I've been following the plan at http://www.musclemedia.com/training/hiit.asp (30 seconds of jogging, 30 seconds of sprinting) and I'm up to 6 minutes this week. I swear, when I'm running, I feel like I'm gonna die, but I'm still pushing myself... Anyhow, I had a few questions: I do this first thing after I wake up (mid afternoon; I work late). I usually do a few stretches first, and walk around the track twice before starting. Is that enough of a warmup? I do this on an empty stomach. I typically go to bed around 5AM and at that point, I may have only had a light, healthy snack. When I'm running, my stomach is growling. Is that bad? My breathing technique may be inefficient because I'm always gasping for air. Any tips on improving this? For the record, I'm 24 and in pretty good shape (5'11", 165 lbs). Prior to HIIT I hadn't done much working out at all. Thanks in advance.