Question

Why do you think a runner will most likely develop bigger leg bones than a swimmer? How does this happen?

Answer 1

it is because of more running and using the legs more running then swimming

Answer 2

A runner primarily only excercise his/her legs, while a swimmer exercises most of his/her body

This is why runners primarily have stronger and bigger leg bones, because their exercise is only focused on making one thing (or two) stronger

hope this helps