" You cannot change your height, the width of your hips, the length of your feet, or any of several other anthropometric variables affecting endurance performance that I have discussed in this chapter. You can’t change your genetic potential for leanness, either. But you can reduce your body-fat percentage (and thereby adjust your weight) to the level that is optimal for performance in your chosen endurance sport given your unchangeable genetic constraints. "

― Matt Fitzgerald , Racing Weight: How to Get Lean for Peak Performance