It’s no different than rowers backs a gymnasts upper body and small lower body (males anyway).[/quote]
Hours and hours and hours of practice of their sport. In skating you are basically holding the ‘‘knees bent 90 degrees’’ position for a combined tension time of an hour a day in practice, not to mention the powerful leg drive with each stride.
It’s the total volume of tension that eventually leads to adaptation in the quads.
I currently train a female speed skater who has humongous quads but a dismal upper body. Previously she did next to no upper body work (recently their coach accepted some shoulder and back work). Even her lower body strength training was minimal (leg press and cleans twice a week). When you see the size of her quads you’d expect a lot more strength training volume.
NOTE: the above workload was NOT from me; it’s from before she started working with me.
I always smile when people ask how gymnast train to get their body… they think that doing a few chin-ups, dips and blast straps work once or twice a week will get them there.
Gymnast (and rowers, and speed skaters, etc.) have the body they have NOT because of the exercises they do, but mostly because of the amount of total loaded (even if it’s just bodyweight) work they do.
Do chin, dips, bar work and ring work 30 hours a week and you’ll build a huge back, arms and shoulders. Doing it 30-45 minutes a week will NOT give you the same results.