Equestrian sports: Athleticism of the rider

The other day I read an article in the New Yorker.  It was about human physical individual differences and how it makes one person better at a sport than another. Examples:

•  Why are guys and girls from Kenya so successful at running? Well, for one thing -- they have long, skinny, but most importantly, light weight lower legs. Think about the impact of just a few ounces over the course of a long run.
• One high jumper was found to have an unusually long achilles tendon, and he only trained eight months before competing in the Olympics -- the tendon gave him more leverage/bounce. 
• A champion skier was found to have an unusually high number of red blood cells than the average human -- more red blood cells, more oxygen. 

What does this mean for riders? Certainly longer legs and a certain body type can help, but look at the many exceptional riders who don't conform to this 'ideal.' I think more general whole-body skills have more to do with it.

Late to the party
I'm behind the curve in coming to grips with the fact that people who are good athletes tend to be good riders. Body control, fine motor skills, flexibility, and of these things make someone good at tennis, or skiing,  and riding, I bet. Geez, I regret all of the years I avoided competitive sports after a few superficial failures. I wish I could turn back the clock and fail my way to more success in sports.

On the plus side, I've started running again! It's not going to make me agile like tennis might, but it's a winner from a cardiovascular standpoint. Three miles in 30 minutes, three times a week!