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Saturday, July 23, 2011

Tour 2011: Alp d'Huez, leaving the mountains and onto the TT

Tour de France 2011: leaving the mountains and onto the TT

The Tour de France is now only one day away from finally answering every question posed of it, and its riders, almost three weeks ago.  A time-trial in Grenoble holds the final answer:  Schleck or Evans?

But much fell into place during the Alp stages - we now know that Contador wasn't quite up to the challenge this year (though the relative effects of the Giro and the knee problems are not known), we know that Andy Schleck carried good form into week 3, and we've seen Cadel Evans' strength and consistency, and has certainly had the least drama-filled Tour.  We also finally saw Thomas Voeckler pay for his great performances, but he certainly inspired along the way.

Aggression in the Alps

Yesterday's stage up the most famous climb in the race, Alp d'Huez produced some incredible racing.  If the Pyrenees were described by the word "conservative", then the Alps were the polar opposite.  Aggression was the feature, not only yesterday but all the way back to the foothills of the Alps where Contador ignited the race through his attacks on Cat-2 climbs.  Then on Thursday, it was Andy Schleck, launching with 60km to go, and finally, to bookend it all, Contador attacked even earlier, on the Col du Telegraphe and pulled Andy Schleck away from the chasers.

That brought a concerted effort from BMC at the front of the peloton on the Galibier.  At one point, Contador and Schleck had almost two minutes' advantage over Evans and Schleck, but BMC first held it, then slowly reeled it back, before Evans found himself, for the second day in a row, pulling the peloton up to an early break with a Schleck in it!  His effort closed the gap to around 30 seconds by the top, and on the very long 40km descent to the foot of Alp d'Huez the gap was removed.

So had you tuned in then to watch the final climb, it looked like just another day.  It had been anything but.  Meanwhile, Thomas Voeckler was doing a ride to admire, if not wonder about slightly - he tried to follow the Contador/Schleck break, but wasn't quite able to bridge.  And he hung to a tantalizing gap of around 30 seconds for a big part of the Galibier.  It went to 40 seconds, then he fought it back to around 20 seconds.  Then it went up, then it came down.  Voeckler the yo-yo was agonizingly close, and at times, less than 100m away from the group.  But he couldn't quite close it and within the final 4km of the climb, he finally cracked.

He was reeled in by the pressure from behind, and promptly dropped from that Evans group as well.   Perhaps, in hindsight, having failed to bridge, he might have waited for the chase group and been pulled back by them - but this is easy to say afterwards.  Fact is, Voeckler was inspirational.  While he managed to catch up on the descent, it seemed that barring a miracle, his yellow jersey tenure was over, but not without providing some of the race's great performances and highlights in the process.

Alp d'Huez: instant separation

Then on Alp d'Huez, the race exploded (I'd say "literally exploded" but that's what Paul Sherwen says, and fortunately, it's not quite true!).

And it's worth analyzing some of the performance times for different stages of the climb, because they show how Contador actually cracked about two thirds of the way up the climb, after an incredibly strong bottom third.

The historical context of the climb is equally interesting - the 41:21 climb of Sanchez was the fastest of the day - that's a return to the times we saw in the 1980s, when bicycles were considerably heavier.  However, I don't want to become too repetitive because the issue of performance analysis and characterizing the power of the climbs has been a regular feature of our Tour coverage this year.  So rather than spend minutes on it now, I have included that discussion in a separate "sub-post" section at the end of this post, for those who are interested in further debate.

If you want the summary though, the times yesterday do little to dissuade me of the view that performances are universally slower, and by a considerable amount.  Of course there are tactics, and there are varying conditions, but consider for example that all three regularly completed HC climbs in this Tour have been over three minutes slower in this Tour than were seen the 1990s and 2000s.  And not a single HC climb in the last two Tours have been done at anything close to 6.2 W/kg, let alone the 6.4 W/kg seen in years gone by.

And so the combination of performance times decreasing, the physiological implications of those performances and the bio-passport data suggest progress in the anti-doping fight - only more time will confirm or disprove that hypothesis.  For more, check the bottom of the post.

Contador's climb - hard, medium, crack pacing strategy

Contador's times were easiest to record, because once he attacked with 12.5 km to go, he was on camera most often.  I'll look at Roland's times relative to his, to give an indication of how the climb was structured by the two of them - it's very different.

So Contador rode the whole climb in 41:30, but it was set up with a first 3.8km of 11:24.  The next 5 km would take him 15:59 and then the final 5km 14:07.  His speeds thus dropped from 20.1 km/hour for the first 3.8 km, to 18.8 km/hour, before increasing to 21.3 km/h for the final segment (which includes some leveling off right at the summit)

Rolland, on the other hand, rode the first 3.8km in about 12:34 (he started 50 seconds ahead, then was caught and a gap of ± 15 seconds opened).  His next 5km was done in about 15:51 and the final 5km in 13:29.  His speeds per segment were 18.3 km/h, 18.9 km/h and then 22.2 km/h.

That is put into perspective when you consider the profile of the climb.  The first two kilometers are the steepest of the climb at over 10%, before it becomes more gradual, and then gets steeper at the top again.  Contador therefore attacked in the steepest part, and rode over a minute faster than Rolland over the first few kilometers.  He then slowed progressively even though the roads got less steep, and Rolland was able to hold him to 20 seconds before closing the gap and winning the stage.  This is further illustrated by the time gaps to the yellow jersey of Thomas Voeckler who held Contador to around 2:45 for much of the final 5km.

Contador therefore cracked, and that's partly the toll of stage and earlier aggression, both on the climb and those before it.  It's also because he probably rode well above capacity in those first 5km - I don't know the precise elevation of the climb by kilometer, but perhaps someone does and can estimate the power output per section based on the above splits?  The fact that Contador was faster on the steeper earlier slopes than from about 10km to 1km to go says much about how he ran out of reserves towards the top.  It was all Contador could do of course - he had to throw everything in and he did (to his credit).  In the end, just too much to ask.

Pacing strategy and the time-trial

And speaking of pacing strategy, perhaps that's a good point to leave the mountains and talk time-trial.  Today will see Cadel Evans try to overturn a gap of 57 seconds to Andy Schleck to win yellow.  I've spoken to a number of people about their projections and they range from a 2 minutes loss for Schleck to an equal performance!  Clearly, there will be some intrigue!

The two biggest problems with trying to guess the outcome of the final time-trial of the race are 1) the cumulative effect of fatigue is so difficult to predict, and 2) riders often don't ride them at 100% or with the same incentives at stake, because they don't need to.  Therefore, when you look back over the last few final time-trials, you find cases that support either position.

For example, in 2009, the final time-trial of the race was 41km (comparable length), and Cadel Evans beat Andy Schleck by 30 seconds.  But, that was a race where Evans began that time-trial well off the lead, whereas Schleck was in contention for the podium.  To highlight this even more, in last year's final TT, Evans finished 166th and over 5 minutes behind Andy Schleck!  Again, this was the time-trial where Schleck was fighting for the race win, Evans had little to gain and came off what was a relatively poor Tour and was riding with injury.

This year, that's quite different.  Evans has been strong and consistent - he's followed every attack, he's shown the strength to pull the peloton up two mountains in the last two days and he looks really solid for the win.  There's the yellow-jersey effect, of course, in that being in yellow supposedly adds the motivation necessary to find a better performance.  And while that's true, I don't believe it's a competitive advantage in a race like this.  Consider Cadel Evans - he has been trying to win the Tour for years and has come close on a few occasions.  Is there more motivation than that of a rider who knows his chance is 60 minutes of effort away?  I've always found it quite presumptuous to try to guess at people's motivation anyway.

The next issue is fatigue - Andy Schleck has had two enormous days in the Alps - a 60km break and then yesterday's efforts.  Cadel Evans hasn't exactly had it either though - he did all the work on the Galibier on Thursday and a great deal more yesterday.  But his allocation of effort has been more controlled and maybe a slight edge here.  Again though, it's impossible to guess at recovery and even effort allocation unless it's quantified, so this doesn't really help.

Pacing strategy is another interesting one.  When you're talking about an hour of riding and 53 seconds advantage, then small 1% differences as a result of pacing can be telling.  Going last is a slight advantage in that regard, because you know what the targets are.  And Schleck may be able to pace himself off Evans.  However, that's pretty meaningless if Evans is 2 minutes faster - all that will happen is that Schleck will be "pulled" too fast over the first half, and pay in the second.  So it will be fascinating to see how the relative gaps between the two unfold and how they structure their effort.

All in all, it should be a fantastic day.  We'll see what it throws up in terms of analysis and bring you the final yellow jersey tomorrow!  Thanks again for reading and discussion!  One day to go!  (and I won't lie, as enthralling as it's been I feel the need for holiday!  The Tour de France really is grueling!)


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The historical overview of the climb

In terms of the historical context of the 2011 performances, the overall time for Contador was 41:30.  Sammy Sanchez was the fastest of the day in 41:21, while Pierre Rolland, first to summit, did it in 41:52 because he started the climb with a 51 second lead (bear in mind small errors in timing off the TV - I'll watch it again and correct small errors later).  

It does not escape notice that the times were comparable to what we saw in the 1980s.  In the 90s and 2000s, sub-39 minute performances were expected, after Gianni Bugno and Miguel Indurain had been the first to break 40 minutes in 1991.  In fact, since 1994, seven of eight climbs have been done in under 39 minutes, let alone 40 minutes.  

Carlos Sastre in 2008 rode a 39:30, a sign of the passport, perhaps, and this is the first time (unless I'm missing something) that the fastest ascent of the climb has been outside 40 minutes.  And it wasn't just slightly outside - Sanchez did 41:21.  And many have commented that this fails to account for the earlier climb and tactics. True, but the size of the effect is too large to be dismissed.  The earlier efforts on the Galibier (which were not as massive as many think) might account for some of the difference, but this climb was over four minutes slower than Pantani's record, and 3:30 behind the times of 1995, 1997 and 2001.

Implications for power output

In terms of the implications for power output, below is the graph that I showed the other day as well, courtesy Alex Simmons.  It shows the expected climb time for different power outputs and different wind speeds.  On the note of wind, I have watched the climb three times now and there seems to have been a breeze in the trees, but the flags on camper vans and poles on the climb show very little wind, so I think the effect was minimal, but to give the benefit of the doubt, assume a headwind.  

Without wind, the climb was done at an estimated power output of 5.65 W/kg.  A headwind would push it up towards 6 W/kg.  At this point, it's worth saying that Chris Anke Sorensen (who we've been following all Tour) rode Alp d'Huez at 5.3 W/kg, and finished the climb in 47:10.  So just over five minutes off.  Within the relatively linear region of this graph, those 5 minutes are worth about 0.7 W/kg, so that puts the top climbers at ± 6 to 6.1 W/kg.  An alternative method is to take the Sorensen performance (47:10 and 5.3W/kg) an estimate the headwind and then derive the power output for the faster time of 41:30.  Turns out that it it predicts a headwind close to the yellow line shown above, and so the race leaders are climbing at an estimated range of 6.0 to 6.1 W/kg.  And that's a highest case scenario, I suspect it to be lower.

This is exactly what I'd expect of this level of rider at their maximal efforts at the end of a three-week Tour, as seen today, and as has been seen the entire Tour long.  To repeat a common observation in the Tour - this is much, much lower than we used to see in the 90s and 2000s, where climbs over 6.2 W/kg and higher were common place (for some of the data, see this post) and the lack of those performances now is conspicuous.

Of course, Alp d'Huez has rarely been done after such aggressive riding on the preceding climb.  Then again, it's rarely been done after only 93 km of riding either - today's stage was short, the total riding time "only" 105 km and took 3:13:25. 

And I readily acknowledge that any one climb in isolation paints a picture of nothing.  But I'd point out that this year, there have been three HC climbs that are regularly done in the Tour - Luz Ardiden, Plateau de Beille and Alp d'Huez.  Every one of them has been more than 3 minutes slower than the record times for those climbs, all of which were set in the EPO and blood doping era of the 90s and 2000s.  The same was true last year, incidentally - not once was an HC climb done at more than 6W/kg, whereas that was common in the 90s and 2000s - 6.4 W/kg was the average back then.  Even when you correct for tactics and weather, the number and magnitude of those differences is compelling.

The dividing line, I believe, comes in 2008, when the biological passport was introduced (and please read this for the context).  And now, as the Tour rolls out of the mountains again, it has once again suggested to me that a) performances of greater than 6W/kg (let alone the 6.2 to 6.7W/kg we used to see) are not credible and that b) the doping problem, while no doubt present, is coming back under control thanks to the stringent testing.  Obviously, this is still a hypothesis - let's get thirty or forty climbs that are slower, not the five or six in the last two years.  But so far, the data support the hypothesis, and only time will tell if it's true.  

Thursday, July 21, 2011

Tour de France: Andy throws down the gauntlet

The high Alps, Part 1: Andy Schleck rides to a big win

So if anyone saw today's stage coming, I'd be very impressed.  In case you missed it, Andy Schleck, one half of the Schleck brothers who had been widely criticized for their lack of aggression and attacking in the Pyrenees, attacked on the second to last climb of the day, with fully 60km to ride, and was able to first build the lead, then extend it, then defend it, and he won the day by just over 2 minutes from a group that contained brother Frank, Cadel Evans, Ivan Basso, and Thomas Voeckler, who produced enough to hold onto yellow by 15 seconds.

Andy Schleck moves into second overall, and Frank Schleck is third, 1:08 off Voeckler. Evans is still well positioned in fourth, 1:12 off Voeckler but only 57 seconds behind Andy Schleck and with the long individual time-trial to come, still looks a good chance to win this Tour overall.

Notably absent was Alberto Contador, who fell out of the chase group with just over a kilometer to ride, but who never looked particularly sharp throughout the stage.

Schleck's break

Schleck attacked on the steep parts of the Col d'Izoard, 60km from the finish, and soon found himself a minute clear.  Nobody in the group behind was chasing, and by the summit, his lead was over two minutes.  On the descent, he opened up further time and put himself into virtual yellow, and still the urgency from behind was not apparent.

At 16km to go, it was 3:45.  14km to go, 4:01.  At 12km, 4:08.  It maxed out at around 4:24 with 10km to go, and then it gradually began to come down - it was Cadel Evans who led the chase, going to the front of a big group of over 30 riders and slowing eating into the lead.  The steepest part of the climb was the final 8km and this is where the lead would come down more significantly.

Cadel Evans did all the work in the final 10km, and eventually, his efforts did reel Schleck back in somewhat. But Schleck climbed at a strong pace for most of the climb, conceding perhaps 5 to 10 seconds per kilometer, and it was a question of how much time he'd gain, with the stage win already secured.

The final kilometer saw Schleck finally pay for his long, solo effort.  Having had a 2:38 advantage with 1 km to go, Schleck finished up winning the stage by 'only' 2:07.  He thus lost a full 31 seconds in the final kilometer (having lost 52 seconds in the first 7 km), and that was enough to allow Thomas Voeckler to claw back control of the yellow jersey, for at least one more day.

In the end, then, Schleck was the big winner today, of course.  But, it's interesting to note that he climbed the steep Galibier (8.3km) about 1:45 slower than the chase group (give or take timing errors - I haven't had the time to manually time it, just yet.  Maybe later tonight).

That's obviously because his effort was spread out over the Izoard, the descent, and the more gradual climb of the Lauteret, whereas the chase group really only rode aggressively in the final 10km of the race.  All in all, a great ride by Andy Schleck, and perhaps opportunistic is the word for it, because he capitalized on the race situation.  However, having said this, I still find myself agreeing with Chris Boardman, who tweeted "I am speechless at these tactics" when he referred to the chase and how lacking in urgency it was on the easier descents and flatter parts of the day.

The chase tactics and a lack of urgency

Not to take anything away from Andy Schleck, but the urgency in the chase was noticeably absent today.  Schleck was thus the beneficiary of a game of 'poker' behind him, with none of the leading riders wanting, perhaps, to risk expending energy over so long a period to pull him back.

And this is partly understandable, of course - it's a risk to pull everyone along and be beaten in the final climb.  No GC teams wants to do work and lose out in the final reckoning.  But the problem is that it wasn't necessarily about charging on up the road to eat into the 2 minute lead that Schleck was allowed to gain on the Col d'Izoard.  Nor was it about going to the front on the Col du Lauteret to get Andy back before the summit with really aggressive riding.  All it needed was upping the pace just slightly, showing some urgency, to hold the lead to say 3 minutes, rather than the 4:30 it got to on the easier part of the race (the descent and gradual slopes of the Lauteret), so that the time gaps could be controlled.

The fact is, when you have 30 + men in a chase group, then it's not a true 'chase' group - it's just the front of the peloton.  And what is curious about this is that it's not as though any of the main leaders were isolated - all had team-mates with them, and again, we're talking a small increase - descend at the same rate as Schleck and climb the easy slopes at the same speed and the gap is held to 3:00.  What happened is that the GC rider's teams didn't want to work together, and the pace of the race at the back was really very slow.

We'll get confirmation of this when the power output data become available, but the climb of the Izoard was done at a relatively comfortable pace by the main peloton, and that is what allowed a) Schleck to build over 2 minutes by the summit, and b) about 25 riders to stay in the group.  That this lead grew on the descent, and in the transition to the Lauteret, further tells the story of a race that was allowing 'poker' to have an influence on the result.

So we'll look for Sorensen's data to give some insight into how the elite race progressed on the Izoard and the early slopes of the Lauteret, because he was there until the pace was ramped up 10km from the finish.  But expect some pretty low numbers - if I had to guess, I'd say that the main group rode the Izoard at 5.6 to 5.7 W/kg (and so Andy Schleck would have produced around 6W/kg for the final 5km of the climb), and the Lauteret was even slower.

The fact is, the chase group would eventually do the final climb fully 1:43 faster than Andy, and that's entirely down to the allocation of energy resources in the stage - basically, it's pacing strategy.  And to finish that fast relative to Schleck paints a picture of Schleck's huge efforts early (and remember, 31 of those seconds came in the final kilometer), but also of a really sedate effort from behind.

Tactical games 

The thing about race strategy is that there's always an interplay between what is good for one and bad for another.  Ideally, you want to do what is best for you at the exact time that it is worst for another, whether it's in a bike race, a marathon, or even a rugby or soccer match - your best scenario, their worst.  Simple equation, and it works because tactically, one's gain is often another's loss! (this is not always the case - sometimes there's mutual benefit, or neutral scenarios, but often this it is a zero-sum game)

Now, there can be no doubt that Andy Schleck and Leopard-Trek pulled off a major tactical coup today - over 2 minutes gained, and a protected day for Frank Schleck (who may see the benefits tomorrow on Alp d'Huez).  For them, the tactics were just excellent.  But inherent in this fact is that the tactics for others were not.  A few people have debated this, suggesting that there was nothing unusual in the response of the riders to Schleck's attack and the lack of urgency of their chase.

But there's an internal inconsistency here, because if you believe that Andy Schleck rode with a tactical plan that was ideal for him today, then inherent in this is that the strategy adopted by other GC teams was definitely not optimal.  Neutral for some, perhaps, but certainly strange for others.  If Andy benefitted from his attack, then someone lost.  So the likes of Evans, Contador (although to be frank, he didn't have it today) and co lost out as a result of failing to deny Schleck and Leopard-Trek what they wanted, what was ideal for them.  One's gain is another's loss!  Had this been rugby, football or soccer, analysts would say that they were outplayed, and in that case, they are tactically questionable.  And that's why the tactics left some speechless.  Given that Evans ultimately pulled back so much of that gap, having begun so late, it's worth wondering what the perception is from the teams.

The saving grace is that Evans has, by virtue of his earlier form in the Tour and the fact that he lost time to the "right person", stayed close enough to be the favorite for the TT, provided he loses no more time.  Contador, as mentioned, didn't have the legs to do anything anyway, and probably neither did Voeckler.

Ultimately, as good as Schleck was, he didn't do anything outrageous - it's not like he produced the fastest ascent ever to ride away from an aggressively pursuing pack.  He rode an incredible ride, over sixty brutal kilometers, but opportunism won the day, not pure wattage.

The race from here - Alp d'Huez all set for another Schleck showcase

As has been the case almost every day, the Tour leaderboard looks subtly different every day.  Today, it sees Andy Schleck rise up to second and put himself squarely into the yellow jersey argument.  The only consistency in that leaderboard is Cadel Evans, who remains a strong likelihood to top the podium in the Tour.  He is now only 1:12 off Voeckler, and 57 seconds behind Frank Schleck, and you have to think that with the individual time-trial to come, someone needs to take time out of Evans.

Today, Evans rode incredibly hard, doing a mountain (literally) of work to claw back almost two minutes on Andy in the final climb.  Tomorrow sees the final climb of the race up to the finish of Alp d'Huez and that may be where Frank Schleck looks to attack and gain time ahead of the time-trial.  Frank Schleck had about as comfortable day as one can have on a stage with three HC climbs on it, but it sets tomorrow up well for him!

Given Andy's efforts, it would not be too surprising to see him ride more conservatively tomorrow, but he too would want more time.  So both perhaps will be bargaining on Evans' efforts from today costing him too much.

Voeckler - one more day in yellow.  Or how about two?

And what of Voeckler?  He has shown so much heart, and let's give credit, riding ability in this Tour, that he can't be totally discounted yet, not for a podium finish at worst.  He has not yet cracked, and today, he showed that when the race goes as fast as possible, he is able to ride with the very best.  The lead group of the Tour, led by Evans, climbed the Galibier at what really is maximal effort today - nothing was held back, it was pure max effort, and Voeckler was able to stay in the group.  A great ride, again, of more than just guts, but also ability.

He has only 15 seconds advantage on Andy Schleck, but if Andy feels today's efforts in his legs tomorrow, then the gap to note is the 1:09 to Frank Schleck and 1:12 to Cadel Evans.  And based on what I saw on the Galibier today, I wouldn't bet against Voeckler holding that yellow jersey for one more day!  As I said the other day, to lose 1 minute on a climb will require that Voeckler cracks - if he climbs at the level he has on three mountain-top finishes so far, then he will not lose that much time, and so only Andy Schleck is in position to claim yellow off a strong Voeckler tomorrow.  And that's the key - Voeckler needs one more climb like he's shown all Tour, and I can't see anyone but Andy taking yellow.  Once the time-trial begins, of course, it's another story.

As for Contador, his Tour is now over, he lies in seventh, 4:44 down.  I wouldn't count out some big effort tomorrow, since this is really his last chance, and given his standing in the race, he may be allowed to go clear with a few kilometers to go.  However, I think the larger race situation will probably mitigate against this.  More likely is another conservative day for Contador, and the relinquishing of his title confirmed.


The Tour of questions is now starting to see answers taking shape.  If I had to guess at the likely result now, I'd make Evans the favourite, by virtue of that time-trial.  Unless he loses time tomorrow, he is in the best position to top the podium.  Will he pay for his efforts today?  Only time will tell.

The Schlecks and Voeckler seem most likely to battle it out for second, third and fourth, the relative positions hopefully becoming a little clearer tomorrow, on the sport's most famous climb!


Tuesday, July 19, 2011

Tour de France 2011: Rest day musings

Tour 2011:  Rest day, risk-taking and relative margins

The Tour is enjoying a rest day.  Call it the calm before the storm that awaits in the Alps, starting on Wednesday.  Most of my thoughts have been covered in my last two posts, first on the state of the race (and the sport, really) in the Plateau de Beille post and then yesterday, giving some context to the performances by looking at the biological passport and how it seems to have altered doping behaviour.

But, today being a rest day, it's a good chance to catch our breath and look ahead.  I'm absolutely snowed in with a research grant application due today, so I had time only to throw together some quick thoughts.

Anxiety among the GC contenders?

If you look at the current leader board, the name that jumps out instantly is Thomas Voeckler.  His presence there is only part of the story - the real plot is the apparent ease with which he marked all the attacks on the Plateau de Beille, controlling the race with aplomb, in the manner one might expect Contador and Schleck to do.  He didn't hang onto the jersey, he controlled it.

I'll get to Voeckler shortly, but in terms of "anxiety" (too strong a word, but let's go with it), the question is around the other GC contenders.

First, the Schlecks.  Currently in second (Frank) and fourth (Andy), they trail Voeckler by 1:49 and 2:15 respectively.  What attacking there was in the Pyrenees was primarily instigated by these two, as was the tempo on the early part of the climbs, with their Leopard-Trek team doing most of the work.  The source of any concern for them will surely be the relative ineffectiveness of both the tempo and their attacks.  The team effort at the front saw fully 30 men ride the first quarter of the climb together, and their attacks were marked sharply and neutralized.  Contador responded to all but one of them on the Plateau, and Voeckler was similarly responsive.  To date, only one attack by Frank Schleck has gained time (if we ignore the little sprint that got Andy two seconds the other day).

The Schlecks may well have more in the tank, and they'll need to find it, because front of their minds, alongside Voeckler, will be Cadel Evans, who is arguably the best time-trial rider in the Top 5.  He currently concedes only 17 seconds to Frank and is ahead of Andy by nine.  So the Schleck's thinking must surely be that if we could skip the Alps, and jump straight to the time-trial, they're not winning this Tour, even if they can beat Voeckler by 2 minutes!  So the onus is squarely on them to attack and to make an even bigger effort to a) drop Evans and b) trim Voeckler's lead to at most a minute before Saturday.  That's cause for some nervousness ahead of the Alps.

Then there is Evans.  Of the top 5, he may have the least to be concerned about in terms of the race situation.  His time-trial ability affords him the luxury of not having to attack, though there there is the 2:06 to Voeckler that might concern him.  But for him, the anxiety takes the form of doubt.  Will he be able to avoid even 10 bad minutes in the Alps, let alone a bad climb or day?  Those 10 bad minutes might cost him a minute, be it to Voeckler, the Schlecks, Contador.  And if that happens, it doesn't end Evan's Tour hopes, but they're under threat.  A bad day, two or three minutes, and his Tour hopes are over.  And so he'll climb knowing that attacks must come, from the Schlecks, as mentioned, and Contador, as we'll discuss next, and his question is whether he will be able to respond?

Contador next.  His hold over the Tour (and his streak of six consecutive Grand Tour wins) is slipping away, and the Alps are his only chance of setting up a win.  His gap of 4:00 to Voeckler is bad enough, but the 1:45 to Andy Schleck and 1:54 to Cadel Evans make his Alp performances rather desperate.  He must attack.  And if (or when) this happens, he might ultimately be the catalyst that decides this race.

Whether he can make up the necessary time remains to be seen.  His Pyrenean performances were unusually 'flat', and that has one of two explanations.  Either he is carrying fatigue over from the Giro, or his knee and other problems that affected him in week 1 were hampering him.  If it's the former (Giro fatigue), then expect Contador to lose more time and at best, respond to attacks in the Alps.  No gain, only maintenance,and more likely is that he'll get worse.  But if it's the knee, then the rest day, and the two easier days following it, may just see him regain some form.

Contador holds the key?

And with form may come a Contador attack.  If that happens, Contador may actually have the decisive say in where this year's final yellow jersey is going.  Up to now, we've seen attacks from the Schlecks, but they've done little to the other big 5 (we've added Sanchez!)  If Contador attacks, and if it's anything like a typical move, then he won't just sit up and allow the regrouping we saw in the Pyrenees - it'll be a prolonged attack, or repeated attacking, and the field will be split, if only for a short time.  That may be the platform that the Schlecks, Basso, or Evans need to finally break the race open.  The irony then is that it may be Contador who holds the key, even though his chances of winning the race overall need more than a few good rides from him.

Basso has climbed solidly, and even shown signs of aggression.  His time-trial abilities have always been questionable (he lost about 4 minutes to Cadel Evans in the recent Dauphine time-trial over much the same route as Saturday's TT), and so he's in the same situation as Contador - he must attack before we leave the Alps.  Whether he has that ability is a question, and I suspect at best, he'll be the beneficiary of others' aggression and rides strongly without making a decisive move.

Aggression vs conservatism, and the Alps to force the risk-taker's hand

There's been some great discussion in the previous two posts about the apparently cautious strategies to date, and suggestion that more aggression is needed.  I feel that the Alps will provide this aggression, a risk-taking style of riding that we didn't see in the Pyrenees.  The simple reason is that in the Alps, the strategy is going to be dictated by the approaching time-trial rather than the current GC standings, and as mentioned above, there are riders who absolutely must take risks.

The thing about strategy, and particularly in the Tour de France, is that it's like a game of poker with one crucial difference - the cards you have and the way you play them on one day has repercussions for the cards you'll have the next day!  A big effort one day - call it a large investment or spending of energy - will invariably be followed by a poorer day the next, so the key is to decide how to spread the investment most effectively.  This is pacing strategy on a grand scale, not the allocation of 'physiological resources' within an exercise bout, but over many repeated bouts.

And while I'm not going to go on about the doping issue, since that came across in the post on the weekend, a cleaner Tour would place a premium on those resources - they are not infinite.  They never were, but they're now far scarcer than before (call them a precious resource) and so conservatism will invariably rule.  And when you get that caution, then riders who ordinarily might be 1 to 2 minutes down as a result of perhaps those 3 to 4% differences in capacity, are able to survive, the beneficiaries of 'doubt' so to speak, and so this caution is also responsible for the expanded groups we've seen on the climbs so far.

Of course, it is possible to ride aggressively - take advantage of a "good day" and really go for it, with a long attack.  But the problem is again shown by the poker analogy - as in poker, you don't know what cards the other riders hold, and so you have to try to decide what's best for you, worst for them, without complete information!  You don't even know whether your cards will hold throughout the day, and so even on a single climb, a big attack 11km out could prove costly, because the ability to sustain the kind of super-high power outputs needed to accelerate away from a group and then maintain an advantage is limited to maybe 25 minutes.  Time it wrongly, and you'll be going backwards with 2 km to go and the result is a lost Tour.

But the Alps will force this risk-taking on the race, and that's why it should produce some fantastic racing!

Voeckler - the margins and the implications

Finally, there is Voeckler, perhaps the biggest story of the Tour.  I mentioned the other day that Voeckler's lead of 1:49 was large enough to keep him in yellow until the time-trial, unless he drops off the level we've seen.

That's because I don't believe that anyone in that big 7 can elevate performance by more than a few percent.  There's definitely some reserve there, make no mistake, but even a jump to what I consider a ceiling will see them chip away at his lead, not blow it out.  The only way Voeckler is not wearing yellow during the time-trial is if he cracks in the Alps.  If he continues with the form he showed in the Pyrenees, he's in yellow.

And to illustrate this, take a look at the following graph, which was drawn by the always insightful Alex Simmons (who sometimes posts on this site), and taken from the cyclingnews forum last week.  It shows the the predicted time on Alp d'Huez as a function of power output (in W/kg) and with different wind conditions.  The blue line shows the predicted times without any wind.

So for example, climbing at 6W/kg will produce a time of about 39:20.  The question to be asked around the 2011 Tour is how Voeckler might lose a 1:49 lead?  And bear in mind there are two mountain top finishes - the Galibier is longer, comes after a tough stage, finishes at a higher altitude, but it is less steep. Alp d'Huez is the final climb of the Tour.  Both have the capacity to change the Tour leaderboard, but let's look at what it will take.

So below is the same graph, with three additions:

  • First, the blue circle indicates the performance we'd expect if the power output was similar to what was predicted on Plateau de Beille.  There, it's been estimated that the top men averaged 5.7 W/kg for about 47 minutes.  The same on Alp d'Huez gives a time of 41:10.
  • The yellow indicates the equivalent to Luz Ardiden, where the average was 5.9 W/kg (an estimate, admittedly).  There, it predicts a 39:50.
  • The green box indicates that within this range of power outputs, a time gap of 1 minute would be created for every ± 0.2 W/kg difference.  In other words, if Voeckler were to ride at 5.8 W/kg (in line with what he's done so far), then his rivals would need two consecutive days of 6 W/kg in order to wipe out his 1:49 lead.  

So, a few scenarios:

  • If Voeckler can produce the same kind of performance as he did on Luz Ardiden, then he's going to ride Alp d'Huez in around 40 minutes.

    Next question:  how much faster can the others go?  6W/kg gives them a predicted Alp time of 39:20, and so they cut the lead by ± 40 seconds.  Maybe they'll find 6.1 W/kg, in which case they do a 38:50, and Voeckler's lead is cut to under one minute.  Per day, which may see a new yellow jersey by the Grenoble TT.

    Of course, there's a chance that they're already near the limit - perhaps 5.8 to 5.9 W/kg is the capacity.  In that case, Voeckler holds basically the entire lead and starts the time trial with 1:49
  • If Voeckler drops his level even slightly, but the others don't, then expect to see a time gap of 60 to 90 seconds on the climb.  5.6 W/kg vs 5.9 W/kg means just under two minutes on the climb.  One day like this and Voeckler's out of yellow
  • Obviously, if Voeckler cracks big time and rides at even 10% slower than he has so far, then he'll lose significant time, many minutes, and it'll be a race between the top men
Finally, remember that the race is not an individual time-trial or mountain climb. The group nature means that Schleck or Contador riding at say 6W/kg will not simply gain a minute into anyone riding at 5.8W/kg, because he'll just pull him up the hill. So what I described above for Voeckler, the one minute per 0.2 W/kg is only true if a gap is created and it becomes a race against the clock, so to speak.

Therefore, the ability of any of the Big 7 to create time gaps in the Alps takes more than just a higher power output.  It takes an initial attack where the power output will hit 700 to 800 W (11 to 12 W/kg) for a short time, followed by the ability to sustain that higher power output.  You'll often see an attack that splits the group, but then it gradually comes back together - that's because the attacker is able to lift the power output instantly, but not to sustain it, whereas those behind can gradually ramp up and pull themselves back up.

So Contador, again, may hold the key, because his normal attacks will split the group, and then if anyone has the ability to lift the tempo at the front, Contador may provide them with the chance to express what may be the small, but very real, differences between the potential champions and the top 10 riders.

Regardless, it'll be a huge showdown in the Alps, full of intrigue and drama, and with fully seven or eight role-players!

Enjoy the flat stage, and the first Alpine showdown!


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Monday, July 18, 2011

Tour de France: The biological passport context

The biological passport - giving some context to the performances in the Tour

Thank you all for the tremendous discussion on yesterday's post with some insights on the Plateau de Beille stage.  As usual, whatever doesn't come out in the post is brilliantly debated in the comments and discussion afterwards, so thank you for the thoughts and opinions!

Most of the discussion has been around the issue of the 2011 Tour tactics and strategies, and particularly what this implies for doping (or a lack thereof) in the sport.  That is obviously a big talking point - it is implicit in what we are seeing, to the point where I actually tried to avoid mentioning it in the post because I'd rather focus on the racing.  But of course, it's a big issue, and it's also a positive thing for cycling to suggest that the sport is moving in the right direction, so worth discussing.

And so I felt the need to do this post, somewhat reactively, in order to provide some context to the debate and to my interpretation.

Complexity of sports performance

What one has to really understand is that sporting performance is so incredibly complex, that when you watch a competitive sports event (and this is true of any sport, incidentally), so many factors affect the outcome that taking a "reductionist" approach will always be incomplete, and sometimes very misleading!  That is, if you reduce things like performance and racing tactics to being the result of only one variable (in this case, the presence of absence of doping), then you are invariably over-simplifying things.  This is not necessarily a bad thing - simplifying a problem is often the first step to building an understanding of it!  And if you do it systematically, then it's actually the only way to work towards understanding a complex phenomenon like performance.

But it's important to acknowledge the complexity and recognize that there's no proof in performance alone, only context.  And I do think it's valuable context, particularly if you can adopt a systematic approach, and ask yourself "What would the sport of cycling look like WITH doping?".  Make a list of characteristics that you would expect to see if the best athletes doped.  And if you know that, then you can find signs (not proof, take note) that suggest otherwise, that the sport may be getting cleaner.  But I'll post more on this tomorrow, when I'll do some "Rest day questions and insights".

For now, I want to repeat part of a post I did earlier this year on the biological passport.  And this is important, because I want to impress on you that I'm not just basing this idea of a cleaner Tour on the slower times, the less aggressive racing and the power outputs.  There is physiological, anti-doping context as well, and the interpretation of the performance and race tactics actually come AFTER this physiological finding, which is why I interpret it the way I do.  And for this reason, we must revisit the biological passport concept

The biological passport - what is it and how does it work?

I'm not going to go into this in great detail now.  If you're new to this site, or missed the two posts I did on this earlier this year, then click the links below to read more on the bio-passport - this is what I believe has helped produce the results we may be seeing.  The articles are:

It's the second one in particular that might be of interest, and below is a section of that, copied into this article (forgive me for the re-run, but it's relevant right now to the discussion)

The biological passport is an effective deterrent - the absence of convictions is not a symptom of ineffectiveness

I guess the ultimate question about the passport is "Does it work?".  It had a bad rap initially, mostly because people are saying it's caught so few riders, despite suspicion.  There are reasons for this, but I'd argue that actually producing positives is only a small part of doping control.

Allow me an analogy.  Say you have a stretch of road that is known to be a high accident zone as a result of speeding - guys hit 100 mph in the 70 mph zone.  Authorities might decide to install cameras to catch people speeding.  They might estimate that in a given week, an average of 500 cars speed through this section - it's impossible to know the precise number, because it can't be documented without the camera.  Having installed cameras, they review the statistics and find that they are now catching 2 speeding cars per week.  A failure? Are they looking in the wrong place? Not necessarily, for the obvious reason that as soon as drivers know that the risk has increased (provided they also believe that the punishment will be enforced if they offend, of course), they modify their behavior accordingly.

This is an obvious and simple example that just because the passport is not catching doping cyclists, it may actually still be exerting an effect on the professional peloton as a result of what I would crudely describe as "fear" that this new system can catch dopers.  Doping behavior would thus be modified as a result of awareness, and the end result is that authorities might catch FEWER transgressors, but should still feel content that they're getting a problem under control. 

Will people still speed?  Of course.  But will they speed less severely, and try to speed only when not being observed?  Yes, and the end result is positive.  Similarly, cyclists will dope, there is no doubt of this.  But they will be more careful, and that has positive consequences.

Evidence of effectiveness - a fascinating graph

But, you are not going to just take my word for it (nor would I expect this!), so let's look for some evidence.  If the cyclist is changing their behavior in response to the increased chance they will be caught, then you can expect to see changes in the markers that reveal the EFFECTS of doping.  In other words, you apply the Biological Passport concept, and investigate whether things are changing.

So here is a graph that gives me great confidence and hopefully some cause for optimism (thanks to Dr Mario Zorzoli via Prof Yorck Schumacher for steering me in the direction of this graph and allowing me to use it - the reference for the paper is at the end of the post for those who want it)

It shows the percentage of blood samples measured in professional cycling that had UNUSUAL reticulocyte percentages.  You might recall from my last post that:
  • a LOW reticulocyte percentage indicates that there are fewer immature red blood cells because red blood cell production has been switched off - this happens after the infusion of RBC, or blood doping
  • a HIGH reticulocyte percentage indicates that there are more immature RBC, and this happens because of removal of blood or the use of EPO, which both stimulate RBC formation
  • a 'normal' or physiological range for reticulocyte percent is 0.5% to 1.5%.  Anything outside these is suggestive of doping
Source: Zorzoli & Rossi, 2010; Zorzoli 2011           

So, what are you looking at?

The green blocks show abnormal samples where reticulocyte percentage is HIGHER than normal - either 2 to 2.4% (light green) or above 2.4 to 5% (dark green).  Remember that a higher reticulocyte % means more immature blood cells, suggesting EPO use or blood removal.  So quite clearly, in 2001 and 2002, you had a high percentage of samples that suggest EPO use - between 9% and 11% of all samples, and 80 to 90% of suspicious samples.  No surprise there - this was the era of EPO use.

Then comes the introduction of the urine test for EPO in 2002, which I've shown with a blue line.  Suddenly, things change - now, you see much larger pink bars.  The pink represents LOWER than normal reticulocyte percentage - either 0 to 0.2% (dark) or 0.2 to 0.4% (light)

So clearly, the EPO test changed things - from 2003 to 2007, between 6% and 10% of samples had low reticulocyte %, and these tests make up 80 to 90% of the abnormal test results.  Remember, this suggests blood doping, and a shift in practice after the EPO test was introduced.

Introduction of the Passport and another change

Then comes the Biological Passport, shown by the red line in 2008, and immediately, you see a substantial drop in the total number of tests with abnormal reticulocyte %.  This is clearly a good finding, because only 4% of all tests have unusual reticulocyte percentages, a drop from 14% in 2001.  That's an enormous impact, and while it does not prove that doping is reduced, it does suggest that the Biological Passport has had a measurable and expected impact on the sport.

And there is the "elegant" timing where the introduction of a test first shifts the trend from high ret % (EPO use driving RBC formation) to low ret % (blood doping which suppresses RBC formation) and then seems to bring it right down.  This strongly suggests that professional cycling has adjusted its behavior in order to avoid detection, not once but twice - the first was a change, the second a reduction.  The threat has therefore induced change.  But there is more to this - it's linked to performance, and that's what the Tour data suggest.

But first, an important question.  Does this prove that doping is not happening?  Of course not - riders are smart, they micro-dose, they mask doping by using EPO to switch RBC formation back on when infusion would normally switch it off.  There is still corruption, and no science, however powerful will be 100% effective if there is any hint of cover-up.  Going back to my speeding analogy, people will always speed, but instead of hitting 100 miles an hour, they pull back to 80 miles an hour, and they "select" when to speed.  Traffic officials will still accept bribes, officials will cover up some cases, but the overall trend would still be positive.

I would propose that a similar thing has happened for cycling.  There is almost certainly doping, and I will remain a skeptic, but I'm also optimistic that this new method, which will continue to be developed and improved, is having an effect by forcing more caution, and smaller dosages.

That optimism comes in part from this graph, from testimonies within cycling (I honestly believe that cyclists are "nervous" of the science behind the Passport), and of course, performance.

And so that's why when the climbing times are down, when the power outputs drop, when the physiological implications of those power outputs are suddenly "credible" based on what we know about physiological capacity, when the racing is more conservative, when attacks are less frequent, when groups are more bunched, my interpretation is that the sport is moving in a positive direction.

The physiology, the marker for doping, says that doping behavior has changed.  The performances confirm it, and even though each of those things by themselves proves nothing, they mount the evidence, confirm the hypothesis and all in all, I think they portray a positive message!

That's the context then.  Into the future, a rest day tomorrow, and maybe a good time for some questions - what will the last week bring?  So join me for some insights, where I'll try to talk racing as well, not just the doping, because there is a fabulous climax to this Tour on the horizon, much to look forward to!


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Thank you for taking time to read and follow our coverage of the Tour de France here at The Science of Sport. We hope you've enjoyed the insights we've tried to provide!

We run this site as a "labour of love" and will continue to do so, but of course, any support is greatly appreciated. So, if you would like to donate and support our continued efforts to bring you the insights and analysis, please consider donating to our site. You can do so by scrolling up to the top of the page, where you will find the DONATE button at the top right of the page.
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Tour de France: Post-Pyrenees state of the race

The Tour leaves the Pyrenees with more questions: State of the race and insights

The 2011 Tour de France has continued to throw up question after question, and today's finishing climb up Plateau de Beille has proved no different.  This was the stage that was supposed to bring the curtain down on Thomas Voeckler's reign in yellow.  But yet again, as has been the case the whole Tour, for every question that was answered, two new questions emerged and we are still no closer to knowing who will be wearing the final yellow jersey into Paris next Sunday.

The stage today included the brutal pull up the Plateau de Beille, 15.8 km at an average of 7.9%.  It's the hardest climb of the race so far, and it's the final climb of the Pyrenees.  Thomas Voeckler had 1:49 over the chasing group, and the general projection was that he'd be dropped near the base of the climb as a result of the aggressive racing between the Big 5.

Well, it turns out that Voeckler had other ideas, and the only thing we know tonight, as we head into some flat stages before the Alps, is that the Big 5 that consisted of Frank and Andy Schleck, Cadel Evans, Ivan Basso and Alberto Contador now has a new member.  And for the duration of the 2011 Tour, it's the Big 6 - Voeckler is now part of that group, whether by virtue of the amazing climbing form he showed today (he didn't just survive on the climb, he actually responded sharply to attacks and looked composed), or his 1:49 advantage.  And it sets the Alps up as fascinating for reasons that few could have foreseen before the race began.

The climb unpacked

More analysis of the climb will come tomorrow, as soon as SRM publish the data from Sorensen.  That will unfortunately add limited information, because Chris Anke Sorensen stayed with the head of the field for only a few kilometers of the final climb.  However, we'll take a look at that tomorrow.

Some of the estimates for the performance are in, however.  I can tell you that the main group did the climb (by my watch) in 46:53.  Jelle Vanendert, who claimed second on the climb to Luz Ardiden two days ago, went one better and won the stage with an attack about 7 km from the finish.  He did the climb in about 46:05.  Incidentally, the fastest performance on this climb belongs to Marco Pantani, a 43:30 back in 1998 (but this was on a slightly shorter time).  Other notable performances are a 44:17 by Contador and Michael Rasmussen in 2007, and a 45:40 by Armstrong and Basso in 2004.  So today was a slow climb - won in 46:05, with the big favourites doing 46:53.

Tactics, conditions?  Of course, but without wishing to focus a whole post on this, the climbing performances have clearly changed in the last two or three years.  Once-off slower performances on isolated climbs are easily explained by race situation or weather, but it has been two years, and about a dozen climbs, and we see a consistent increase in the time taken to ride these big climbs.  The pattern then is quite clear, and today's performances conformed to that pattern.

In terms of the power output estimates, for those interested, it projects to about 5.9 W/kg for Vanendert, with the chase group averaging around 5.7 W/kg (assuming 65kg riders - the range doesn't change too much).  As mentioned, I'll check the numbers more when the SRM data provide some context.

Tactical sparring

However, this was anything but a one-paced climb.  It was, as expected, Andy and Frank Schleck who were primarily responsible for the repeated attacks.  Those attacks were ultimately responsible for producing a fairly stop-start climb in that chase group, because as aggressive as the attacks were, they were short, and always followed by a lull in the pace as the group rejoined.  The result is that the attacks would stretch the top 10, even causing small splits, but it always came back together, and by around 5km to go, even riders dropped on the early slopes had rejoined the elite group.

Meanwhile, as it had been on Luz Ardiden, the time gap to the leaders out on the road told a good part of the story. At the start of the climb, the gap to Sandy Casar out ahead was 2:10. It was chipped by about 10 seconds per kilometer from then on, until Vanendert assumed the lead with 5km to go. From that point, Vanendert actually increased his lead, because the attack-then-sit up nature of the chase behind was allowing his steadier rhythm to move away.

Massive groups

It's been a long, long time since I've seen such large groups on HC climbs at the end of Tour stages.  The group was 24-strong at 4km gone, and there were 13 men battling it out only 4km from the summit of a finishing climb in the Tour de France (has it ever happened?).  The days of brutally hard tempo riding from the start of the climb, eliminating all but two or three rivals, seem a distant memory.

When you think about it logically, you would expect large groups because a) the differences between riders at this level should small at only a few percent, and b) there is a drafting benefit that is equal to or larger than the natural performance differences between riders at that, even on the climbs at relatively slower speeds of about 20km/hour.  This is what helps the peloton stay together so that 180 men can finish flat stages together, and I dare suggest it's normal for climbs to have so many men together, especially in the first mountain range because the cumulative fatigue effect is so much smaller.

Consider for example that in marathon running, lasting 125 minutes, the gap between the best in the world and 40th best is only 4%, and you realize that it's normal for elite performers to be bunched within a few percent of one another.  Then consider that a drafting effect of only 5% would offset a potential performance effect of 4%, and suddenly, the size of the groups is expected.  This doesn't take into account attacks and the ability to change pace quickly, but when the group is so big to begin with, even rapid accelerations are buffered because there are sufficient riders to gradually pull back attacks.  Only those at their limit are gapped permanently, and that's what we saw today - the top 5 or 6 were riding at one level, and those behind, in the elite group but not in the top 5, were benefitting from repeated accelerations and then slower periods of regrouping.  Had the pace been hard and consistent, that group would have thinned, but still, seven or eight at the front of the race, that's a large group.  But it's encouraging for the sport, and certainly adds to the intrigue of this year's Tour.

Neutralized attacks

Also gone is the destructiveness of the attacks.  Today, Andy Schleck attacked around five or six times (and the attacks came much sooner than on Luz Ardiden), with Frank Schleck making a couple of moves of his own, but each one was marked almost instantly and neutralized.  Only Ivan Basso joined in the attacks, until the final kilometer when Cadel Evans made something of a bid.  Again, they were neutralized almost immediately, and the group was glued together.  In the end, the only attacks that succeeded were those that were allowed to go - first Vanendert and then Sammy Sanchez.

Ivan Basso was actually critical of the Schlecks after the stage, saying that they needed to thin the group down to four or five and then make attacks, rather than attacking when the group consisted of twenty riders.  That's all good and well, but the Schlecks may not have the artillery to make that happen.  Today, the intensity on the early slopes was clearly higher than it had been on Luz Ardiden, but the group remained large - I counted 24 men still in the group a full 4km into the climb.  The Leopard-Trek effort was thus not sufficient to cut the group down.

I am not sure what the Schlecks, or anyone else, can do to cut that group to four or five, as Basso suggests.  The Schleck attacks could perhaps be sustained for longer - they have sat up very quickly after being marked, and perhaps the answer is to go off the front and hold that higher tempo for a few more minutes, to really test the followers.

But that is easy to say.  The question is: Can the elite riders go any faster?  I'm beginning to suspect the answer is no, not by as much as one may think.  The top 6 riders in the Tour (and yes, I'd include Voeckler in this based on today) are locked together so tightly, that I don't see anyone just riding a hard tempo and doing damage to anyone but themselves at the front.  Given how quickly attacks were followed, I wonder whether perhaps the group would form with five or six riders who would then be pulled along by whoever the "risk-taker" is, until he himself is burned off.  Perhaps the Schlecks will have to agree who this will be and the sacrifice can be made, because they will see Evans' time-trial as the big threat to their yellow aspirations.

The Alps - cumulative fatigue effects and look for bad days to eliminate riders, rather than great days to win it

This is what sets the Alps up so intriguingly.  Given how tight and competitive the racing on the climbs has been, it is beginning to appear (to me, anyway) that for any given rider, this Tour may be lost by a bad day, rather than won by a decisive move.  Within that group of 6 riders, one will be eliminated more by their inability to produce the power outputs we have seen in these two mountain top finishes than it is by one big attack and one remarkable performance.

Then there is the effect of cumulative fatigue - in the third week of any Grand Tour, it is fatigue resistance that makes a huge impact, and so we should expect to see a thinning of the numbers, because riders have limited energy and may have allocated a great deal to ride in that group of 12 on climbs like today.  So the group should thin, and perhaps Basso will have his wish of attacking against half a dozen.  But within the top 6, it really is taking the shape that one will be eliminated by a bad day where they lose time to the other five,  rather than by a great day where one of them rides away from the other five.

As the race hits the Alps, however, there'll be a good deal more desperation, longer attacks and less cagey tactics.  The individual time-trial that awaits next Saturday will start to dictate strategy more than the current time gaps do, and it may produce some more risky racing.

I think the Pyrenees have produced hard racing, probably not quite maximal, because of cagey tactical battles and conservatism.  That will end in the Alps, certainly by Alp d'Huez, but probably on Thursday's brutal stage.

Thomas Voeckler - can he hold on?

As for Voeckler, one is tempted to take the default option and say that he "survived" today's stage and kept his yellow jersey.  I think that this is incorrect.  He looked sprightly to me, and covered every move relatively quickly.  I'll watch the stage again, but I don't recall an occasion where he was pulled up to an attack by someone else - he did the work for himself and that suggests that he may not have been at his absolute limit.  If anything, he didn't need to ride as fast and as hard as he did today, and he might well have conserved a little more energy.  But had it been Andy Schleck or Alberto Contador in yellow, everyone would be saying how solidly they controlled the race and how composed they looked.  And Voeckler deserves to be spoken of as a realistic contender now.

As for the Alps, I expect that the intensity will be a little higher, particularly on the finishing climbs of the Galibier and Alp d'Huez.  If we work with the estimations from Luz Ardiden and today (and bear with me - the assumptions are applied to all riders, so it's relative), then it seems that the elite of the race are climbing at an average of 5.7 to 5.9 W/kg.  I expect that this will increase up to 6 to 6.1 W/kg at some point, either on Thursday or Friday (Alp d'Huez).

If we assume that Voeckler cannot match that increase, then he'll lose time, no question.  How much?  Well, over 40 minutes of climbing on Alp d'Huez, if Voeckler rides at 5.8 W/kg as has done in the Pyrenees, and the others ride at 6W/kg, then he'll lose approximately one minute on the climb.  In order to lose the entire 1:49 lead, he has to slow down far more relative to his performances in the Pyrenees - we're talking in the order of 5.5 W/kg, or the likes of Schleck, Evans and Basso have to find a huge increase in power output (which I don't believe is possible).

Of course, it's conceivable that Voeckler will break at some point.  If that happens, and he cracks, then he loses minutes and the race is back on between the big 5.  However, if he can just remain solid, and continue to hold the kind of level we have seen in the Pyrenees, then he looks a good bet to hold that yellow jersey all the way to the individual time-trial, because the main rivals probably have only a minute's worth of 'capacity' or 'reserve' to improve by.   One more day like today, and even a small time loss on the other big Alp day will see Voeckler ride the time trial in yellow.  And of course, there is no guarantee that Voeckler himself doesn't have the capacity to ride even faster than we saw today.  And what a story that would be!

A Tour of questions continues

We started this Tour, two weeks ago, with questions.  Was Andy Schleck timing his peak to perfection? Could Alberto Contador recover and peak again after the Giro?  Would Cadel Evans be able to avoid the one bad day that costs the Tour?  And here we are, 14 stages in, and we have no answers!

Every day, we get new questions.  We still wonder about Andy Schleck.  We still have doubts over Contador, who looked better today, but not back to his best or we would have seen at least one counter-attack.  Is he recovering from week 1 and the crashes, or is he just flat from the Giro?  We are none the wiser.  But we now have a host of new questions, most of them about a Frenchman in yellow who is not merely clinging to the jersey, but controlling it.

All in all, the Pyrenees may have produced some conservative racing, and maybe even frustration in observers wanting longer, more aggressive attacks.  Physiologically, that may not be possible.  But they produced enthralling racing, and that seems set to continue.  A few flatter days now, and a rest day, and then it's the decisive days.  Then again, we said that on Thurday and today!

More analysis tomorrow - will look briefly at Sorensen's data, because it has limited value - we already know the climb today was relatively slow and that the power outputs will be in the same range as they were on Luz Ardiden.  And so we wait for the Alps!


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Friday, July 15, 2011

Tour de France: Luz Ardiden analysis and thoughts

Analysis of Luz Ardiden: ± 5.9W/kg and thoughts

It's a day late, for which I apologize (grant proposals due at work!), but hopefully better late than never, some analysis of the first big mountains of the 2011 Tour de France.

The race's first foray into the Pyrenees went some of the way towards 'cleaning up' the top page of the overall GC, but also left many questions unanswered, and introduced more than a few new ones!

Obviously, with three more mountain-top finishes and a time-trial to go in this year's race, this was never going to be the race's decisive day, but given the profile and the stakes after a tough first 11 stages, much was expected.  At the very least, yellow was expected to change shoulders, but even that did not happen as Voeckler produced a brave, inspired ride on Bastille day.

In the end, the stage is tricky to analyze and interpret, because at times, it was done quite conservatively.  The fireworks that were expected never really came, at least until about 4 km to go, when the first real testing moves came from Andy and Frank Schleck.

The pace of the lead group - the time gaps tell the story

The rhythm and intensity of the climb is best judged by looking at the time gaps between Sammy Sanchez, the eventual stage winner, and the peloton.  Jeremy Roy and Geraint Thomas began the climb with a lead of just over three minutes, while Sammy Sanchez and Vandendert had left the peloton and began the climb with a 20 second advantage.

The 3 minute lead was cut to 1:43 with 10km to go, and it seemed that the race would come together before long.  Sanchez and Vandendert were however edging ahead of the peloton, and when they caught Thomas and Roy at 8km to go, the gap was 44 seconds, meaning that Sanchez and Vandendert had grown their advantage on the yellow jersey group by a further 24 seconds over the first 5km of the climb.  At that stage, there were around 20 riders in the yellow jersey group (there had been 30 a full 3 km into the climb), which itself tells a story.

Meanwhile, back in the peloton, Basso and Sylvester Szmyd of Liquigas had gone to the front with about 10km to the summit.   Their presence may have nudged the pace up very slightly, but it did little to erode Sanchez's lead.  It dropped to 40 seconds with 7.5km to go.  The Liquigas drive was also the impetus behind thinning the lead group slightly  - it had been cut to 18 men with about 5 km to go, an extremely large group so late in the climb.  One of those to find the pace slightly too hard was Chris Anke Sorensen.  Immediately after the stage,  I was very eager to see his power output data because that would confirm the initial impression that the pace at the front of the race was solid without being exceptional.  More on that below...

But over this period, from 8km to 4km to go, the peloton actually slowed down.  Sanchez's lead grew from 40 seconds to one minute, then even more, and with 4km to go, the gap had grown to 1:20.  That means that Sanchez and Vandendert covered a 3.5km stretch 36 seconds faster than the big group chasing from behind.  It was quite clear that the tempo at the front had dropped.  And as well as Sanchez and Vandendert climbed, and as pedigreed a performer as Sanchez is, their climbing performances relative to those of the GC riders reveal that for all the talk and hype about the "brutal effort on the front", the top riders were not throwing every weapon at the climb.  When that finally happened, it was dramatic, and a 1:15 lead would be cut to only 30 seconds within about 2km, around 25 seconds per kilometer (and even more for Frank Schleck).  But on average, the climb today was a shade below the level we may see in future climbs.

Schleck attacks and the race hots up

The attacks, as mentioned, came in the final 4km, when the Schlecks did the expected and alternated going off the front.  The elite group was now cut to only eight men.  The fast-slow tempo with the attacks allowed others to rejoin, and by 2.6km to go, the gap to Sanchez had grown back up to 1:14.  Then Schleck made the decisive attack, and was able to go clear.  This was the catalyst to suddenly reduce the lead - it fell rapidly and with 500m to go, and Schleck had basically bridged the gap to Sanchez.  Sanchez responded, sprinting away to take the stage win, but Schleck had effectively knocked away a 1:20 second lead over 2.5 km.  The rest of the field were only 20 seconds back.

That field did NOT include, most notably,  Alberto Contador.  He lost 13 seconds to the main peloton, apparently all in the final two kilometers.  It doesn't augur well for Contador, because this was not an all-out effort by his biggest rivals.  Their efforts were hard, certainly, and it would be naive to think they had too much more, but the intensity could have been lifted slightly, and that suggests that unless Contador can recover remarkably well, he's in for a very tough few days, first on Saturday and then in the Alps.

A look at the power output values from yesterday will confirm this...

The power output analysis - under 6 W/kg, even at the front

First, take a look at the direct measurement (always the best) of power in Chris Anke Sorensen.  As mentioned, Sorensen stayed with the front of the race for the first 5km on the climb to Luz Ardiden.  He then dropped off soon after Liquigas went to the front.  His power output values, especially for the first 5km, would tell us exactly what kind of power output the lead riders were producing.

Very important point that I must make here - after Sorensen fell off the lead group, the pace of the Big 5 (and Voeckler and co) did not actually increase.  If anything, it slowed, as judged by Sanchez (who himself may have been slowing, remember).  So when you look at Sorensen, you're seeing a measure of the higher range of power outputs recorded on the climb, with the exception of the attacks that came later.

So here is Sorensen on Luz Ardiden (click to enlarge):

The key points:
  • The first 5km, when Sorensen rides with Contador, Schleck and co, the power output in the front is ± 5.8 W/kg (376 W)
  • Sorensen drifts off the back soon after, and completes the stage (final 8km) at 5W/kg
  • His heart rate reaches 172 bpm.  You may recall that on the climb of Super-Besse last Saturday, he attacked on the final climb, having ridden the first 6 min at 6.4 W/kg, and his heart rate there reached 176 bpm.  So this was pretty close to a maximum effort.
  • Once he dropped off the lead group, and settled down to the 5W/kg, his heart rate dropped to around 160 bpm, which is approximately 90% of maximum (I think it's safe to say his max is 176 to 180 bpm)
Frank Schleck's power output

Unlike Sorensen, none of the big GC contenders provide their power output data, but it's still possible to estimate power output knowing the time taken, the gradient and the distance.  This has been done (courtesy halamala over on the cyclingnewsforum), and the calculation is below:

Change in elevation: 979 m
Distance: 13.3 km
Time: 37:21
Weight rider: 67 kg
Total weight: 75.0 kg
Weight bicycle, clothes etc: 8 kg
Grade: 7.4 %
Average speed: 21.3 Km/h

Calculated power output = 394.6 W, or 5.9 Watt / kg

The same calculation over the final 10km, incidentally (where it's steeper, and where more of the climb includes Schleck's attack), produced an estimation of 396 W or 5.9 W/kg.  That is, basically the same.

Implications and testing the estimation

Of course, there is always error in these calculations, and situations where the actual power output will differ from what is estimated.  Wind and drafting factors are particularly important.  However, the data from 2011, courtesy Sorensen, give some real support to the accuracy of the calculations for Schleck.  Remember, Sorensen was riding at 5.8 W/kg to stay in the group for 5km.  Once he drifted backwards, the overall pace was probably slightly slower, until the attacks (distance of about 4km), when it picked up again.  So to estimate that Frank Schleck rode it at 5.9 W/kg over the entire climb seems reasonable to me.  If anything, it's too high.  It would be similar to Sanchez and Vandendert, and their subsequent performances will be interesting to see.

And again, part of the discrepancy might be explained by people saying that the race tactics were in play, that the situation was different, and that Frank Schleck and the leaders were not riding as hard as possible.  And sure, this may be true.  But if you think that can bridge the 10% gap between the likes of the 2003 performances and what happened in 2011, well, I find this optimistic. 

How much faster can the top men ride?  An increase of even 0.1 to 0.2 W/kg, which would project to a sustained power output of 6 - 6.1 W/kg might be expected to give a rider an additional 3 to 4 seconds per km, and they would cover the final 10km of a climb around 40 seconds faster than we saw today.   

For comparison's sake, when Lance Armstrong rode up to Luz Ardiden on the way to winning the 2003 Tour (the famous stage with the fall), his time for the final 10km was 27:08, a full 2:02 FASTER than Frank Schleck yesterday (again, thanks to halamala for the numbers).  The estimated power output for Armstrong then was 458 W, or 6.4 W/kg.

Where all this leaves us is with a couple of realizations:
  1. The big shake-up is yet to happen.  To repeat, I don't think we're going to see massive increases in the power outputs from Luz Ardiden, but I do expect that the climb to Plateau de Beille and Alp d'Huez, for example, which are of similar length (37 to 42 minutes) will be climbed slightly faster.  Look for 6-6.1 W/kg on those slopes, and if that seems a trivial increase, it's enough to create gaps of five to ten seconds per kilometer compared to a guy riding 5.8-5.9 W/kg.  So the big effort still awaits.
  2. All of this further confirms, to me anyway, that there is a "limit" to how much power a rider can produce going up a hill.  I've given the theoretical argument why this is the case before, and I estimate that around 6 to 6.2W/kg on these long climbs is the ceiling for normal performance.  But now, as we get more and more data, we're seeing the same thing emerge over and over - guys just do not ride these HC climbs to finish stages at 6.3, 6.4 W/kg or higher. 

    This is obviously a topic worthy of much more discussion, but that is for the gap between the mountains, when I'll look at it in more detail.
Right now, attention turns to the big stage on Saturday, which finishes on the Plateau de Beille.  As I said right at the outset of this post, there are some unanswered questions and some new questions from Luz Ardiden.  Contador's ability on the climbs is probably the big one - was his bad day a carry-over from the first week, in which case one extra day might have allowed him more recovery and he'll return to better form come Saturday?  Or was his performance the carry-over from the Giro, in which case things will only get worse?

One thing is for sure - if his form is off by even 5% thanks to the Giro, then the Plateau de Beille will expose it more than Luz Ardiden will, because the tempo at the front is likely to be harder (only slightly, but it counts!), and the attacks likely to come slightly earlier.  But don't expect big, decisive moves at 13km to go - those days are gone, along with the days of 6.5 W/kg climbing performances.

The other big question is how do Evans and Basso compete against the alternating attacks by the Schlecks?  Their tactic seems reasonably certain, and it's to go one and then the other, until eventually one move sticks.  Basso and Evans have never really been known for their ability to accelerate on the climbs, as good as they are in the mountains.  And so Contador's apparent lull in form does threaten to make the race a Schleck affair, because Contador was the one rider who could counter-attack.  It'll be interesting to see if the Schlecks just continue to chip out 30 seconds advantages on each stage, up to the time-trial when the race will be decided.

And Voeckler?  Great effort to keep yellow, but will it cost him on the second mountain-top finish?  Only time will tell!

Enjoy the racing!


P.S.  One last word on power - Chris Anke Sorensen's power output data is available for all three climbs in yesterday's stage, and you can see it here.   

Just to summarize:

La Horquette d'Ancizan, 9.9km at a power output of 338 W or 5.2 W/kg

Col du Tourmalet, 17.1 km at a power output of 349 W, or 5.4 W/kg

Luz Arideden:  5km at 376 W (5.8 W/kg) and 8 km at 325 W (5 W/kg)

And finally, here is the climb of the Plateau de Beille, to set the scene for tomorrow's finish: