20 minutes or 4?
i've read some of these, and i'm confused.. people are saying 5 min warmup, then 20 mins of tabata.. but others are saying it's only 4 minutes, so what's with this? is it really only 8 sets of 30 seconds with 10 seconds of rest to make 4 mins of work, or do you do sets of those sets? i want to get into this, but need a bit more knowledge on it. thanks