Niv, you certainly can do either, some of it is a personal choice about whether you like the video led work out or the gym based ME. As you’ve likely noticed the Cham level 4 purposely starts to cross the border into muscular endurance type work much more than levels one through three in my opinion. I would say one of the biggest differences is the ME we have in the training plan has a real progression over the 12 weeks where as with the Chamfit you run the risk of plateaus in your training. If you really like the Chamfit and are an advanced athlete you could add a light weight vest to progress the difficulty.