Welcome to the Science of Sport, where we bring you the second, third, and fourth level of analysis you will not find anywhere else.

Be it doping in sport, hot topics like Caster Semenya or Oscar Pistorius, or the dehydration myth, we try to translate the science behind sports and sports performance.

Consider a donation if you like what you see here!

Did you know?
We published The Runner's Body in May 2009. With an average 4.4/5 stars on Amazon.com, it has been receiving positive reviews from runners and non-runners alike.

Available for the Kindle and also in the traditional paper back. It will make a great gift for the runners you know, and helps support our work here on The Science of Sport.

Sunday, September 02, 2007

The men's 800m - analysis of the event and preview of IAAF Final

Tonight in Osaka, the IAAF World Champs concludes with some potentially great races. One of them, the 800m Men’s Final, which is one of our most anticipated races, could be won by any one of the eight finalists. There are few events that are more open and competitive than this race, with some of the pre-race favourites being eliminated in the semi-finals, such is the unpredictability of the event.

The 800m distance is a fascinating one, and well worth discussing further, because it straddles the divide between what people usually refer to as “sprinting” and “middle distance” running. To some, it is the first of the middle distance events, whereas to others, it’s the last of the sprints. Of course, using such jargon can pose challenges, but generally, when people refer to a sprint, they refer to an event where the athlete goes ‘flat out’. This is of course never true, because even in a 200m race, there is some pacing, as evidenced by people who go out a little too fast and end up faltering in the final 40 to 50m!

However, the fact remains that the 800m is a unique distance, requiring a combination of sprint ability and endurance ability. Coaches (and physiologists) have often spoken of an aerobic-anaerobic divide for different events, and they often refer to the 800m distance as being a 50% split for each. That is, they say that approximately 50% of the energy comes from aerobic sources, 50% from anaerobic. This is a contentious issue in itself, one that I would argue with, as recent evidence suggests there is no black and white split between the energy sources, as is often put. But anyway, that’s another story altogether, back to the 800m event.

It is often said that the ideal way to run an endurance race is to aim for what are called ‘even splits’. In other words, the first half and second half must be run in the same time. If you are a 10km runner, for example, the ideal strategy seems to be to run even pace the whole way. An underperformance happens when you either start too fast and slow down (called a positive split – the first half will be faster) or you finish very fast, running the second half faster than the first (called a negative split). For most recreational runners, aiming for a negative split is probably the prudent approach, recommended as a safety first option.

What all this refers to is the “pacing strategy”, or how the athlete chooses to pace himself over the course of the distance. And at the Science of Sport, we thought it might be interesting to look at what OPTIMAL PACING is, based on the world records from various events, from 800m upwards. Of course, we make the assumption that the world records are optimal, which is of course not always true. Sometimes, world records are set in tactical races, and that affects the strategy. Sometimes, they are set IN SPITE of, rather than because of pacing strategy. But generally, if you take 30 world records, you can be pretty sure the guy running the time is running on the limit of performance, and so the pacing strategy is at least close to ideal. So let’s look at the track events. The graph below shows the running speed for intervals during various track events. We’ll discuss them each, in reverse order.

10 000m distance – even pace is the way to go, with a fast finish

In the men’s 10000m distance, 34 world records have been set in the modern era. It’s quite clear from the graph that on average, the race is even paced, with a fast start, more consistent period in the middle, and the final kilometer is fastest. In fact, in 33 out of the 34 world records, the final kilometer was the fastest of the race. What this means, practically, is that even the elite have left themselves something in reserve for the final kilometer. You may be thinking that this indicates that the athletes are not performing maximally, because surely, if you have enough for a sprint at the end, you might have been able to go quicker in the middle part? And you’d probably be right.

In fact, what is really interesting is to look at the pacing over the different generations. So what I’ve done in the figure below is to break the 34 world records into three groups (somewhat arbitrarily), and show the kilometer times for each group. What you see then is that in the older groups, the pacing strategy was far more exaggerated – the pace slows much more in the middle and the final kilometer is much faster than the middle part of the race. However, in the latest group (which, interestingly enough, is since the Africans arrived on the scene), the pacing is much more consistent – a much more even pace, and though the end-spurt still happens, it’s far less pronounced. What this indicates is that athletes are becoming more and more capable of running even pace, and future world records will be set because the middle kilometers are faster, not the final kilometers. In days gone by, world records could be set thanks to a fantastic final two lap sprint – no longer is this the case – the pace will be even in future world records, and perhaps we have only a few seconds of improvement left.

Men’s 5000m – similar to the 10000m, the pace is even, with a final kilometer kick

There have been 32 world records in the 5000m event, and the pacing is similar to that of the 10000m. The first and final kilometers are faster than the middle three kilometers, which again suggests that the middle kilometers are somewhat ‘conservative’. The final kilometer has been fastest in 21 of the 32 world records.

When we do the same thing for the 5000m, and look at the records in three groups over the years (figure below), it’s also apparent that the pacing strategy for world records is changing – gone are the big drops in pace in the middle, replaced by even running with only a slight increase in pace in the final kilometer. This again suggests that the event is evolving to the point where you have to be able to run even pace – if you start too slowly, you cannot make up the difference in the end, regardless of how fast you attempt to push.

Men’s 1 mile – a much more even pace

The men’s mile event begins to get down into the range where speeding up at the end is a lot more difficult to do. On average, the final lap is run in the same speed as the first lap. In fact, in more than half the world records set, the first lap is actually faster. There is still a drop in pace in the middle part of the race, but the overall strategy is even, in contrast to the longer races, where the fast final kilometer ensures that the second half is usually faster. So here, in the even that lasts about 4 minutes, we see a subtle change, which has physiological relevance. Because the even pace in the mile suggests we are getting down to the point where speeding up at the end is becoming increasingly difficult for optimal performance. Which brings us to the 800m race…

800 m – it’s not possible to run optimal times with a faster second lap

In the 800m event, 26 world records have been set. The top graph below shows the average lap times in these 26 races. It’s immediately clear that the second half is quite a lot slower than the first. Some of you may be thinking, hang on a moment, what about the 200m splits? Unfortunately, they are not available for the 26 world records, but in the ones they are available, they follow the same pattern – the first 200m is fastest, followed by the second, and the pace gets slower and slower.

So this is a departure from what we’ve seen before – suddenly, speeding up at the end doesn’t happen. In fact, in the 26 world records, the second lap has only been faster than the first on two occasions. Therefore, a world record seems to require that you run a fast first lap, and then hang on in the second, but speeding up does not appear to be an option.

Some of you may now be questioning this statement. Among the biggest challenges would be the assumption that you’re seeing ‘optimal performances’. And of course, this is true. If a guy goes out and run 1:46, who is to say that is not optimal? Perhaps it is. However, I still maintain that with this pacing strategy observed in 24 out of 2
6 world records, the best way to run the race is to run the first lap faster than the second. On average, the difference is 2 seconds. This means a first lap of 50 seconds would be followed by a second lap of 52 seconds.

What is even more interesting is that the two fastest second lap times ever achieved in 800 m world record performances were run in 1972 and 1966 respectively. The graph below shows the lap times from all the world records, and if you look at the panel on the right, you will see that the second lap time of a world record performance has not improved in 35 years, since Dave Wottle broke the world record with a time of 1:44.3 (min:s) and a second lap of 51.40 seconds in 1972. The current world record holder, Wilson Kipketer, has broken the world record on three occasions, with second lap times of 52.12, 52.90 and 51.80 seconds. Therefore, a 3.2 second reduction in the world record in the 800 m event between 1966 and 1997, from 1:44.3 to 1:41.11, has been achieved by running the first lap significantly faster, rather than an improved ability to increase running speed on the second lap.

The Figure below shows the lap times for the 26 world records in the 800m event. The left panel is the first lap, the right panel is the second lap

Another interesting fact is that even in the Olympic Games, where the first lap is often tactical and slow, is the second lap slower. The average first lap in the Olympic Games finals is 52.8 seconds and the second lap is 53.4 seconds. They slow down, even with a faster first lap! In otherwords, even if the athlete slows down and runs the first lap quite slowly, the second lap is still slower.

What this suggests is that the ability to run faster during the second lap of an 800 m is limited, and so the optimal pacing strategy may consist of a faster start followed by a relatively slower second lap. I’m going to go out on a limb here and say that if you are an 800m athlete, or you are coaching an 800m athlete, if you want that athlete to run their best, you have to plan for a second lap that is about 2 to 3 seconds slower than the first. So, if the goal is 2 minutes, it’s not good enough to aim for a first lap of 60 seconds. It has to be 58-something, because if your athlete is going maximally, then he should slow down to a 61 on the second lap, giving him a final time of 2 minutes.

Similarly, if you want to break the world record, forget about running the second lap in 51 seconds. It’s not going to happen. Therefore, you must plan for a second lap of 52 seconds, which means the first lap must be 49 seconds. This is also an indication of the sort of speed needed to challenge Kipketer’s world record – you have to be able to run a 400m in 48.5 seconds as part of an 800m race. Your basic 400m speed therefore needs to be down in the 45’s, maybe 46 seconds (but that starts cutting it fine).

So looking ahead to the 800m final…

The 800m final is more likely to be a tactical affair, unless someone has decided that his best shot is to follow in the Women’s champion’s (Jepkosgei) footsteps and go as fast as possible. This means the race will be roughly evenly-paced. I suspect the first lap will be run in about 52 seconds (wild guess), meaning that the second lap will probably be run in about 52.5 seconds. You’ll note that this is still a slower second lap, which is really interesting from a physiological point of view – why can you speed up in a 1500m, 5000m and 10000m race, but not the 800m race? Is it a different type of fatigue? Again, I’ve said this before, but it’s worth repeating – we don’t really know what causes this, and if anyone says they do, they’re lying! It’s quite a mystery.

But for the race, it means that the athlete who has the ability to maintain speed is likely to come out on top. In the past, the Olympic Champion, Borsaikovsky, has mastered this. He has earned a reputation as being the fastest finisher. I hope that by reading this, you now appreciate that this is not true – he is in fact not the fastest finisher, he is just the least slow finisher!

The race will then come down to the final 300m, where tactics will be incredibly important. As will speed-endurance – the ability to sustain a fast pace on the second lap, running as close to even splits as possible is a unique physiological ability. That is what makes the race so unpredictable. For my money, it will come down to a repeat of the Athens final, Mulaudzi versus Borzakovskiy, but keep an eye on Laalou, the Moroccan, to spring a surprise. But hey, take your pick, anyone could win this one, it should be a great race!




Anonymous said...

thanks alot im a high school track athlete who is looking for help in lowering his time and has decided to take a more stategic view on the 800m race and this article greatly helped and i also agree with the fast fist lap and slightly slower second. I give a lot of cedit to the author of this article and as i sated earlier thanks.

Anonymous said...

Is your analysis based on split times of the race winner or the times of the leaders at the 400m?