I have been doing Insanity for the past two weeks. It's sheer hell , but perversely I enjoy it.
However, I don't know how to keep my core contracted/ tight/ etc as Shaun T (peace out :)) keeps telling me to.
If I hold my stomach in, I forget to breath and if not my stomach just flops about while I/m trying to suicide jump or power jack my way through each session.
maybe I should try hip hop abs y'all.
I do love it though- it's the longest continuous exercise regime I've ever done !!