So CrossFit is not enough for you? Try SealFit. SealFit is a fitness program developed by a former Navy Seal. CrossFit is part of the concept, but workouts are much longer.
CrossFit was the big fitness trend in 2013. Is the new thing SealFit? SealFit gets a lot of attention this week via an Reuters report.
SealFit is taking the training of US Navy Seals to "normal" people. It is though super hard and only for people who want to go to the extreme.
Former Navy Seal commander Mark Divine developed the program. He authored: "8 Weeks to SEALFIT: a Navy Seal's Guide to Unconventional Training for Physical and Mental Toughness."
SealFit is not just physical fitness, but also a program to improve your mental power. I already find CrossFit hard, so SealFit would break me, but I guess that is the idea. If you go to your limits you can grow not just physically, but mentally - the pain though to go through to get there... Below is a video from a recent Level 1 Academy at the SealFit HQ in San Diego.
See also the SealFit site.