I read this in Hierarchy of Fat loss at T-nation. I don't really understand it. What's the difference between HIIT and High Intensity Aerobic Interval Training???

Well, HIIT is anaerobic (does not use oxygen), while I assume Aerobic Interval Training is aerobic and does use oxygen. I haven't read the article though, so I'm not positive if that's what you were meant to get out of it.

Do you have a link?

http://www.t-nation.com/readTopic.do?id=1526539

owoed basically hit it. I've seen the article you're referring to.

Aerobic intervals are just variations in general intensity...like...if you're running 5 miles, picking up the pace a bit for a half a mile at a time or something. Still exercising at a level you can maintain for a while. John's HIIT routines (especially the first one) fit this description. Warm up at 60%, then intervals at 60, 70, 80 and 90% _effort_ (not % max heart rate - just a judgement call about what effort level you're putting in). His other routine is a 60%/90% effort alternating routine. Each finishes off the training time with a 100% effort (prior to cooldown).

I've been using those routines a bit lately, but I also do some full-on anaerobic work. I'll do a longer warmup of 5-10 minutes, and then do 30 seconds at absolute max effort, and then 30 seconds at 60%. I'll do that 4-5 times, then just maintain the lower effort for 5-10 minutes and do it again. This is what the "hierarchy" recommends, but 99% of us mere mortals can't handle this kind of effort 5 days a week.

I can attest to the effectiveness. When I was just doing LISS, I never seemed to get in much better shape. Now I can beat an elevator up 4 flights (from ground to 5th floor) and not really be winded. :D Still got a long way to go though.

Either one of them will get you results/burn you calories. While HIIT (anaerbolic) is still probably the most effective, the most important thing is that you're doing cardio. For me personally, I like to incorporate both HIIT and lower intensity cardio into my weekly routine.

Hope this helps.

Oh, so BFL style HIIT would be considered aerobic intervals?

Oh, so BFL style HIIT would be considered aerobic intervals?
I haven't looked over the BFL program in years. Can you remind me briefly what the recommended cardio is?

There are 10 intensity levels. You warm up at level 5, then 1min at 6, 1 min at 7, 1 minute at 8 and 1 minute at 9. Then you bring it down to level 6 and repeat until the last minute. At the last minute, you go for level 10.

I would assume aerobic for the most part. The last minute would be anaerobic though, since it's sprinting.

Let's see what others have to say though.

There are 10 intensity levels. You warm up at level 5, then 1min at 6, 1 min at 7, 1 minute at 8 and 1 minute at 9. Then you bring it down to level 6 and repeat until the last minute. At the last minute, you go for level 10.

That sounds like aerobic interval work. I don't know much about BFL, but I think that program is meant for many beginners, and I think if they threw at them anaerobic HIIT, they would probably quit right away.

Anaerobic HIIT is very uncomfortable. You must work very hard, much harder, IMO, than with aerobic exercise.

Yeah, if that's what BFL says then I certainly would call that "aerobic".

It's a good workout to be sure. When I do aero intervals by John's plans I end with a good sweat in a reasonably short workout time...but nothing like when I do anaerobic intervals.

When I do aero intervals, my heart rate stays between 130-155 most of the time (I'm 37, so that's a theoretical 70%-85%) only stretching up to ~ 170 towards the end of the 100% interval at the end.

When I do my anaerobic intervals I pretty much stay over 160 and I've seen 180 a few times.