Has anybody ever used the program sold by the makers of Insanity designed for people at athlete-status fitness? (Can't remember what it's called...Apollo Anton Ohno and Hope Solo do the commercials for it).
Well I only did a few weeks at a time before having to stop for some reason, but in that time I did see a lot of definition in my body. I'm slim and in shape anyway so there probably won't be any drastic change.
The cardio does make it easier for me to run for my military fitness tests. I did about 2 weeks of Insanity and knocked more than 1 minute off my 2-mile run time and I wasn't anywhere near as tired as usual.