hako saidAugust 23, 2007 at 2:48 am Sorry, too many generalizations for me. Male strength and bone density, according to science, peaks between 35 and 45 years of age. Most endurance athletes reach peak performance in their late 20′s to early 30′s. Roger gets his power from the leverage of his long arms, shoulder rotation and racket head speed. He could work on his core, if anything, but he doesnt need bigger “guns”. Also, Nadal’s round butt is not an anchor, it’s probably largely muscle, which he can use for acceleration while sprinting. It’s no coincidence that sprinter typically have massive thighs and glutes…..and they dont slow anybody down.