Breaking the Wall

Sasha,

I have a question for you. Two guys John and Dan like to run. They train togther and race against each other alot. When they race John always beats Dan in a 100 meter, 200 meter and usually in a 400 meter, but Dan beats John everytime at an 800 and 1600 and a usually in a 5K. Sounds normal enough so far. But when John and Dan race the longer distances 10K, half marathon, and marathon John always beats Dan and the distance, and the mph only seems to get bigger. Both train about equal amounts of time and close to the same mileage. Any good explantion for what would cause that?

Several things are here at play. First, it illustrates that the traditional fast-twitch you are sprinter/slow-twitch you are distance runner model is oversimplified. There are a lot of factors that determine your ability to sprint, and there are also a lot of factors that determine your ability to hold the speed as the distance increases. Those factors change as the distances increase.

For example, when the race is over 10 K fuel issues become significant. So John might be deficient on aerobic support, excellent with fuel and peak muscle power, but also not necessarily good at sustaining the muscle power even if the aerobic support is adequate. Dan, on the other hand could be deficient on the peak muscle power but good at sustaining what he has, strong aerobically, but very bad with fuel.

It is commonly assumed that the ability to sustain muscle power is primarily an aerobic function. It is true that if the aerobic component fails the power will not be sustained for a long time. But the reverse is not true - given the adequate aerobic support there could be limiting factors on non-aerobic nature. For simplicity I call that nervous system failure even though it could involve a whole lot more. In other words, aerobic endurance does not equal power endurance.

We must also note that same training for two different athletes does not always produce the same results. While it is safe to say that solid aerobic conditioning is a must for everyone, past that training must address the existing weaknesses in a way that the athlete responds best to. In this example, John should train for 800 meters and the mile, and Dan should do a lot of 10-15 mile tempo runs to fix his fuel issues.

This is, of course, assuming that both have been running at least 70 miles a week year round for the last three years. If not, they should build their aerobic base first so they will know what is really going on. Lack of aerobic base can distort the picture quite a bit.

Thanks for the insight on this it is great help.