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View Full Version : Whats the preferred HIIT work/rest interval?



twm
05-03-2009, 08:36 PM
I have searched around, read powermanDL's thread on HIIT, googled etc, and found many variations. Is there a consensus here as to what interval is best for fat burn? He was suggesting 15/45 or ever 6/9 work/rest. I've been doing 20/10 a la Tabata, which is very hard.. especially on the last 2 work sets. What I want to do is the most effective regimen but I haven't been able to find a reliable, definitive answer

Tabata only goes for 4 minutes (not including warmup/cooldown).. some people were saying they do 15/45 for 10-12 minutes. What is best?? :help:

KingJustin
05-03-2009, 09:34 PM
There's not reliable evidence that is going to tell you an exact number. It's just way too individualized. What the research suggests is that the greater you can make your intensity, the higher your heart rate will stay for longer (and therefore burning more fat). Point being that excessively long work periods will not result in a very high intensity because you can't sustain it over the whole work period.

So, determine the max pace you feel comfortable sustaining (even if just for a few seconds) without getting injured.
Then, decide on how long you can sustain that pace over several rounds. (this is the work time)
Then, give yourself an appropriate level of rest based on your recovery ability. (this is the rest time)

A longer rest period is generally preferred for just burning fat. A shorter rest period is generally preferred for improving your cardiovascular ability. Don't take that to an extreme either way (i.e. max work:rest should probably be 1:3or4, and minimum work:rest should probably be 1:.75 or so).

What this probably boils down to, is that if you are in "ok" shape (i.e. 7 minute mile), you probably want a 12-15:25-35 or so.

twm
05-04-2009, 05:53 AM
Fair enough.. I'm going to stick with the 4 minute Tabata protocol and see how it goes for another 2-3 weeks. If I don't see some results in that time frame, maybe I'll try 15/45 for a more prolonged period of time. thanks

KingJustin
05-04-2009, 08:43 AM
If you are going to do tabata, I would do more than one 4-minute round. 4 minutes is fine for when you are just beginning, but you wan to build on that. Why not do a 4-minute tabata "set" of sit-ups in between run attempts, for example?

(i.e. four minutes of tabata running, 4 minutes of tabata sit-ups, 4 minutes of tabata running?)

twm
05-04-2009, 11:38 AM
have you tried doing that? i doubt i'm capable of that, frankly. by the time i'm done with my 8th 20s work set of my 4 minutes, my legs are like jelly.

Hellrazor
05-07-2009, 06:16 AM
Huh ? Sit ups dont work your legs at all so whats the problem ?

twm
05-07-2009, 04:54 PM
I gave it a try yesterday doing biking then decline situps. i didnt have even remotely the same intensity that I had with biking. also with situps, there is the possibility of failure. i failed on the 6th 20s work set averaging like 10-12 per 20s.

it just seems to me there are are diminishing returns with prolonging HIIT conducted in this manner.... but I'm not exactly running marathons over here either. I'm just trying to burn fat. Justin, do you do multiple tabata sets? its very challenging.

KingJustin
05-07-2009, 07:27 PM
Well, before, you were doing 4 minutes of intense sprints. Now, you're doing 8 minutes of intense sprints with an easy 4 minutes in between. I see that as a progression. (btw, I've always felt like doing sprints on the bike is trash because my legs wear out way before my lungs ... maybe I just never developed enough muscle endurance to appreciate it though)

Also, if you can handle an exercise that is more exhausting than sit-ups, then do that exercise. Burpees, thrusters, double unders and C2 Rows (if you have access), snatches, and clean & jerks are all really good for making you really tired before you hit muscle failure. Just keep the weight as low as you need to.

Last, tabata for exercises like push-ups/sit-ups/pull-ups (etc -- exercises where you reach muscle failure before your lungs give out) will generally improve muscle endurance a lot, and will help cardio a bit. That said, yeah, you'll probably hit muscle failure and not be able to spend all 20s working until you've been doing it awhile. That's OK. (If you are concerned about recovery, then don't train to failure ever)

ThomasG
05-09-2009, 05:02 PM
I do 3 rounds of tabata resting 60 seconds between each round.

twm
05-09-2009, 05:43 PM
i'm going to try biking then burpees tomorrow i think. probably another 5 min of casual biking as a cool-down after that.

Sensei
05-10-2009, 07:19 AM
If your main goal is fat loss, I don't know that Tabata is necessarily the best option. It all depends on goals, but running through multiple rounds of Tabata kind of defeats the purpose - IMHO, if you're going to do that, you might as well be doing some version of EDT because it's essentially the same thing.

Lyle McDonald has/had a lot of articles and blog posts about fat loss and interval training. They were very good and worth your time if you want to actually know something about EPOC and HIIT - they'd be here:
http://www.bodyrecomposition.com/

VikingWarlord
05-10-2009, 08:54 AM
If your main goal is fat loss, I don't know that Tabata is necessarily the best option. It all depends on goals, but running through multiple rounds of Tabata kind of defeats the purpose - IMHO, if you're going to do that, you might as well be doing some version of EDT because it's essentially the same thing.

Lyle McDonald has/had a lot of articles and blog posts about fat loss and interval training. They were very good and worth your time if you want to actually know something about EPOC and HIIT - they'd be here:
http://www.bodyrecomposition.com/

Truth.

twm
05-10-2009, 10:38 AM
link (http://www.bodyrecomposition.com/research-review/research-review-effects-of-exercise-intensity-and-duration-on-the-excess-post-exercise-oxygen-consumption.html)

The link is an article about interval training from Lyle. I assume this is what you're referring to, Sensei. From what I understand, having read this, there is no benefit of interval training beyond an amount of EPOC that Lyle seems to be implying to be negligible. The duration of the interval training itself seems to be the driving factor (not really a surprise, unfortunately). Furthermore, apparently, I'd be better off with prolonged, less intense intervals such as 30 min stair master interval 45s fast/45s slow. Correct? In fact, the individual interval length probably doesn't even matter as long as its strenuous.....

KingJustin
05-10-2009, 11:10 AM
Really interesting article. This, and the theory that after 3-6 weeks, HIIT might become very ineffective for fat loss turns a lot of beliefs on their head.

I took some quotes from the article for the people that don't have time to read it. EPOC = Excess Post-exercise Oxygen Consumption

[T]he picture that has developed from the research is that EPOC goes up linearly with increasing exercise duration but exponentially with increasing intensity.
The paper concludes that, despite the variability in studies, the intensity of exercise appears to be of the utmost importance in terms of generating an EPOC. No argument there.
...
There is absolutely no doubt that higher intensity activity generates a larger EPOC
...
[But] The absolute magnitude of the EPOC simply doesn’t amount to very much in the first place. [For example, o]ne interval study, which found a 14% increase in metabolic rate via EPOC measured an irrelevant 32 calorie afterburn. Yayyy.
...
The simple fact is that the calories burned during activity are going to contribute the most to calorie burn, not EPOC and focusing on increasing that value is going to have a much larger impact on calorie balance (all other things equal) than worrying about EPOC.
There was also some commentary regarding the fact that you can't make great conclusions regarding metabolic weight training, or heavy weight training, because of limited studies. (It is nevertheless my opinion that you can almost always generate a higher EPOC after these sessions than nearly anything else)

Anyway, I think this article does support the theory that the higher your intensity in cardio (% max heart rate), the greater the metabolic effect, and therefore the greater the number of calories burned. BUT, it turns on its head the idea that the actual number of calories is going to be significant in the first place. You'd be a lot better off burning the calories during your cardio, according to this article.

My take from it: For the purposes of fat loss, do maximally intense cardio for as many rounds as you can (thus, shorter durations and longer rest so you can maximize intensity), and follow it with low-intensity cardio.

Mr. Mustard
05-24-2009, 05:35 PM
people were saying they do 15/45 for 10-12 minutes. What is best?? :help:

15/45. Does that mean 15 second sprint 45 second rest? re'tarded question, I know.

KingJustin
05-24-2009, 06:43 PM
15/45. Does that mean 15 second sprint 45 second rest? re'tarded question, I know.

Yeah, 15/45 = 15 second sprint, 45 second rest.