I've read a bit about high intensity training (tabata, hiit, crossfit, etc.) and there seems to be quite a good bit of evidence supporting their utility. The 7-

I've read a bit about high intensity training (tabata, hiit, crossfit, etc.) and there seems to be quite a good bit of evidence supporting their utility. The 7-minute workout may well fit in that same category. However, as an old fogie, I recall a craze back in the 70s and 80s called 5BX, which stood for 5 basic exercises, created by Swedish aircrew iirc. The reason I recalled it is the mention of rapid-style jumping jacks and push ups in the 7-minute workout. 5BX had increasingly quickened routines for jumping jacks (from a crouching position), sit-ups and push-ups (with claps thrown in as you completed each push-up). All of this worked very well in terms of actually toning your body, getting a good daily cardio workout, and a sense of fitness... until it did irreparable back and other damage to quite a few people. So just be careful, especially if the high intensity and the 7 minute time limit drives you to a regimen that gets anywhere close to a 5BX style work out in terms of quick, jerky movements. Personally, I've reverted to playing basketball like I did in my college days, with high intensity worked into it with repeated lay up, jump shot routines, etc. It's working great for cardio and overall body toning. I would like to do weights as well, as there is a body of evidence pointing to its value, but basketball is plenty far for me at this stage.