Muscle ups are one of the most advanced moves in the regular CrossFit arsenal. Muscle ups are just plain hard. The vast majority of the strength and fitness training population, almost by definition fitter and stronger the vast majority of the non strength and fitness training population, will have to train long and hard to get one, if they ever will. A massive pull combined with a super deep push, the muscle up is one of the real rites of passage in CrossFit.
But, every great now and again someone walks in and just nails them. Like AJ.
On the minute for 12 minutes:
1 Full Snatch (Heavier than the previous week)