Even or positive splits seems to be best in events greater than 800? 24 out 26 of the WRs in the 800 were run with positive splits as documented in the Science of Sport article
http://sportsscientists.com/2007/09/iaaf-world-champs-mens-800m/
Is there research backing up a physiological explanation for positive splits in 800 being more effective?
These questions came up on another thread,
From the other thread:
What most runners and coaches don't understand is that the physical demands of each event change AND SO DOES THE PHYSIOLOGY OF EACH ATHLETE WHO SPECIALIZES IN THEM. Take two runners running 800m. One is a 400m runner, who can tolerate 17mmole lactate without breaking down in form or pace. The other is a 3000m guy, who cannot acquire more than 7 mmole, as he has not done the lactate-tolerance work and is not genetically predisposed.
If both do the first 100m in say, 13.0 sec, the physiological effect is very different. For the 3K guy, he sprinting all out, and will soon have to drop from the race. The 400 guy is comfortable and can continue, with a gradual slowdown, for an overall positive split, say of 26/28/28/30=1:51. The 400 guy wins of course.
If instead the 3k guy goes out in say, 14.0 sec the first 100, then his lactate is tolerable (under 7mmole), and he can continue without decrease of pace, as his superior aerobic engine dissipates any further addition of lactate. So running this way, he can run 28/28/28/28 and contend at the wire for the win. So two athletes, two strategies for the win.
Now the 800 specialist has the lactate tolerance of the 400 guy, and also the aerobic support of the 3K (or at least 1.5K) guy. So his best race will fall in between the two: 27/28/28/29. So you can see where the typical 2-sec. positive split for an elite 800 race comes from. For those who are chosen and train the event, it has a "special" characteristic, due to a higher lactate tolerance than found in distance events. Distance races do not start out near a sprint the first 100m, as it would impose too high a lactate load for the remainder of the race. For the 800 it can be done, due to the special training (and genetics, not all runners can build high lactate)
This effect is even greater in the 400. No top 400 runner will ever win against serious competition with even splits. They would feel as if they are jogging the first 200 and losing the benefit of accumulating lactate to run a faster overall time.
Read more:
http://www.letsrun.com/forum/flat_read.php?thread=7499401&page=3#ixzz4EnxpfAte
YMMV, your comments seem very reasonable. Do you know of any relevant peer-reviewed research?
The most impressive part is where the runner runs for 112 seconds but records a time of 1:51.
YMMV wrote:
From the other thread:
What most runners and coaches don't understand is that the physical demands of each event change AND SO DOES THE PHYSIOLOGY OF EACH ATHLETE WHO SPECIALIZES IN THEM. Take two runners running 800m. One is a 400m runner, who can tolerate 17mmole lactate without breaking down in form or pace. The other is a 3000m guy, who cannot acquire more than 7 mmole, as he has not done the lactate-tolerance work and is not genetically predisposed.
If both do the first 100m in say, 13.0 sec, the physiological effect is very different. For the 3K guy, he sprinting all out, and will soon have to drop from the race. The 400 guy is comfortable and can continue, with a gradual slowdown, for an overall positive split, say of 26/28/28/30=1:51. The 400 guy wins of course.
If instead the 3k guy goes out in say, 14.0 sec the first 100, then his lactate is tolerable (under 7mmole), and he can continue without decrease of pace, as his superior aerobic engine dissipates any further addition of lactate. So running this way, he can run 28/28/28/28 and contend at the wire for the win. So two athletes, two strategies for the win.
Now the 800 specialist has the lactate tolerance of the 400 guy, and also the aerobic support of the 3K (or at least 1.5K) guy. So his best race will fall in between the two: 27/28/28/29. So you can see where the typical 2-sec. positive split for an elite 800 race comes from. For those who are chosen and train the event, it has a "special" characteristic, due to a higher lactate tolerance than found in distance events. Distance races do not start out near a sprint the first 100m, as it would impose too high a lactate load for the remainder of the race. For the 800 it can be done, due to the special training (and genetics, not all runners can build high lactate)
This effect is even greater in the 400. No top 400 runner will ever win against serious competition with even splits. They would feel as if they are jogging the first 200 and losing the benefit of accumulating lactate to run a faster overall time.
Read more:
http://www.letsrun.com/forum/flat_read.php?thread=7499401&page=3#ixzz4EnxpfAte
To fix the arithmetic, the 400 guy, the 800 guy, and the 3k guy do 1:42, but split differently.
That is the magic of high lactate tolerance ;)(my math was off, but hopefully conveyed my point)
Lenny Leonard wrote:
The most impressive part is where the runner runs for 112 seconds but records a time of 1:51.
As for the "peer-reviewed research", I suspect that pacing and physiology is too specialized a subject for academic study, especially compared with say, the marathon. My conclusions are from decades as a coach and athlete in these events.
tldr; If you are a
400 specialist: 2-4 second positive split may be your best strategy, in order to take advantage of your superior lactate tolerance.
1500 or longer specialist: consider even splits to take advantage of your superior aerobic capacity.
800 specialist: 1-2 second positive split to take advantage of your strength in both areas.
Of course weather and competition must be considered for adjusting the optimal strategy.
The only "magic" of lactate tolerance is that it is conjured up nonsense. Lactate does not impair performance, it fuels it.
Acidity may impair performance, but the concurrent presence of lactate ions doesn't imply correlation with that acidity, which is to say, it's not "lactic" acid. There are a lot of other anions involved.
The important thing is getting rid of the excess CO2, and while gas transport is the vehicle for this, it's not the 1500 specialist who is best at it, but the 800 or 400h specialist. They have the biggest aerobic engines. Oxygen use is fastest when the pH gradient between blood and muscle is greatest.
Positive splitting is best for nearly everyone, including distance runners, because you will get the greatest power output when you prime your aerobic respiration by quickly lowering intramuscular pH, i.e. going out fast. Going out slower is playing it safe, ensuring a strong finish with no risk of rigging up, but you won't set PR's that way unless it's your only way. And it rarely wins the big races either. Everyone else has to die, and you have to get through the traffic too.
Racehorses always positive split.