For Crossfit, I’d suggest checking out “Mobility WOD” where a Physical Therapist who works with athletes breaks down do-it-yourself maintenance for functional range of motion, that will help you stay injury free.
A friend was talking about how Crossfit could be an interesting model for discipleship: Camaraderie around a common goal, positive peer pressure, challenge/accountability, intentionality, etc. 

There’s some really good practical in this post, for being a good steward of body and mind. I still wrestle with where the sweet spot is between human discipline and Christ-empowered living. I guess it’s always obedience beyond what we can handle on our own, and trusting him to come through, even if obedience is getting up early to pray and workout.