Why do are Olympic sprinters mesomorphs and long distance runner look like starving refugees?

Question

Yes, this is a physics question.

Answer 1

its all about their training. Runners who race above 800m have a completely different training regime. Sprinters lift heavier weights with less reps and long distance runners do the opposite. also long distance runners have much higher mileage in their training  

Answer 2

People who actively participate in strenuous activities tend to be thinner than others who do not.  I know there are Sumo Wrestlers, for example, who have DIFFERENT shapes and their activities are strenuous, but it is a short time burst versus the long distance runner's extended activity.

Also, these folks train to do what they do, developing the body shapes needed to have success in their own sport.  A 12,000 calorie a day diet would make me quickly look like a Sumo wrestler, but a gold medal winning swimmer can use that many calories a day just training and racing.

Finally, there is the issue of air drag, momentum, and a whole batch of other items involved.  Thin means less air drag.  Light means less energy need be expended to accelerate (increase momentum).  Do these kinds of ideas help you?

Answer 3

They only look that way on TV. In real life, you'll be amazed how muscular these long distance runners are. Of course COMPARED to sprinters, they are less developed. Sprinters need strength, whereas distance runners need endurance.

***

OK, sprinters need more acceleration, therefore they must have muscles that can provide a large force.

Long distance runners need to exert a smaller force over a longer distance. In the end they do more work thus must have more energy. Large muscles are not what they need to complete their race. Now if they carry a lot of carbs on their body, that will increase their weight, which in turn will require strong leg muscles. Instead they get their energy from the foods they eat just before the race, and the stuff they drink during the race. Their bodies evolve such that they have a low weight, and a high enough strength to weight ratio.

I still think it's more biology than physics. Or phyiology or biosics.