I hear ya First Blood, but I have been doing HIIT nearly every single day now for the past for weeks, and the results have been outstanding! But, it's possible that part of this could be due to the fact that I am now regaining a previous level of outstanding conditioning, but I haven't had this outstanding level of conditioning in nearly 10 years, when my VO2 Max was measured at 71 ml/kg. Remember... There is such a thing as under-training as well.