yeah ive heard around late 20's for sports that dont destroy your body are your physical peak and you kinda just plateau till your mid 30's IF you keep your body injury free. early to mid 20's for sports that fuck your body up, and plateau for a couple years.
ive heard from multiple people, an athlete marketing agent and a race car driver, that peoples prime in most sports is their early to mid 30's its when your minds more mature and sharpest, your body is still in peak physical form, and it gives you enough time to have a good amount of experience in your sport.
makes sense to me, you look at all the best quarterbacks, pitchers, race car drivers, skiers(who dont destroy themselves) etc.. they usually show their dominance around early to mid 30's. id say the best skiers i know of in freeskiing right now are around that age, when you count more than just park. (i think people get bored of park more than anything)