Yeah, there's a "golden ratio" (if you will) of physical builds and APFT scores approaching 300. Medium/small-built, lean bodies excel at body-weight-resistance strength endurance tests. It's why most Ranger candidates have very similar builds, right around 5'6"-5'9" and 145lbs-170lbs, they tend to naturally be the guys that can pull themselves through the Darby Queen and then head off for another 6 weeks chock full of wick-fun Hooah(TM)*
* - See also: Masochists' fantasy.
[Edit - That story is pretty ****ing amazing though. The sheer will to wake up after 6 months, your entire body aching as bones are still trying to realign themselves, and to decide to not only begin walking again, but to try to regain a physical condition comparable to your former SOCOM level, that's the definition of resilient.]
omnia mea mecum porto