Krygen XL "Man ." After some steroid cycles, Krygen XL production slows down and estrogen increases. The user will develop female breast tissue unless they take an estrogen suppressant during post cycle therapy. I experienced this personally. It is not very attractive.Everyone seems to have their own opinion on sit ups. Some say they aren't good for the spine, others say they are the best exercise for overall abdominal development. To be honest, I'm on the fence. I don't recommend doing 200 sit ups every day but I do incorporate them into my programs. Like other muscle groups, it's important to train your abs with variety.