HIIT is High Intensity Interval Training.

HIIT is NOT interval training.

HIIT was originally developed by a Japanese scientist (Tabata) who wanted to mess around with athletes. He gave them the hardest workout they had ever had - and it was only FOUR minutes.

(Skip this quote if you aren't sciency)

"Seven students, also young and physically active, exercised five days per week using a training program similar to the Japanese speed skaters. After a 10-minute warm-up, the subjects did seven to eight sets of 20 seconds at 170% of V02max, with a 10 second rest between each bout. Pedaling speed was 90-rpm and sets were terminated when rpms dropped below 85. When subjects could complete more than 9 sets, exercise intensity was increased by 11 watts. The training protocol was altered one day per week. On that day, the students exercised for 30 minutes at 70% of V02max before doing 4 sets of 20 second intervals at 170% of V02max. This latter session was not continued to exhaustion. Again, V02max and anaerobic capacity was determined before, during and after the training.

"In some respects the results were no surprise, but in others they may be ground breaking. The moderate-intensity endurance training program [Note: Control group not doing HIIT] produced a significant increase in V02max (about 10%), but had no effect on anaerobic capacity. The high-intensity intermittent protocol improved V02max by about 14%; anaerobic capacity increased by a whopping 28%.

"Dr. Tabata and his colleagues believe this is the first study to demonstrate an increase in both aerobic and anaerobic power. What's more, in an e-mail response to **** Winett, Dr. Tabata said, "The fact is that the rate of increase in V02max [14% for the high-intensity protocol - in only 6 weeks] is one of the highest ever reported in exercise science." (Note, the students participating in this study were members of varsity table tennis, baseball, basketball, soccer and swimming teams and already had relatively high aerobic capacities.)" (http://www.cbass.com/FATBURN.HTM)

(end of quote)

The surprising finding was that even with highly conditioned athletes who should have already been at peak condition, their VO2 max was increased. In other words, they got in much better shape much more quickly than any other method ever before.

In subsequent studies, it was found that HIIT training, when done for just 6 minutes a day, three times a week *for only two weeks* was the equivalent of doing hours of traditional aerobics per week for weeks on end in terms of increases in endurance. What that means is this: People were able to increase their ability to do aerobic exercise from 26 minutes to 51 minutes in only two weeks. That's impossible with traditional measures.

In other studies, those participants who did HIIT were able to burn actual fat (not water weight, muscle, etc) at NINE TIMES the rate of those who did traditional aerobics, even in cases where they burned less calories total, because this type of exercise if more efficient at burning fat and raises your metabolism.

HIIT also has an anabolic effect - that is, instead of catabolic, muscle breaking endurance exercise, HIIT supports muscle growth - as long as you eat enough.

Now you are wondering - I'm doing interval training, more than 4 minutes, but I haven't seen the results! Here's why: you're not doing HIIT. Sorry.

Keep this in mind - if you read the original study, the college athletes, who were already in good shape - were vomiting after 4 minutes. They mentioned that in the actual published report. They were not "going hard" for a few seconds. They were going AS HARD AS THEY COULD. (170% VO2 max!) Not pacing. Not anything.

If you can do HIIT more than three times a week (which you should not) and you are not already a conditioned athlete, you are probably not doing HIIT. It should take all the energy you have to get through a workout that only takes up to 4 minutes or so. That isn't to say that what you are doing isn't beneficial, won't work, etc. That's just to say - you're doing interval training, not HIIT, so you shouldn't misrepresent HIIT to people who are learning.

Here's the basic workout. Can be done running, biking, etc.

10 minute warmup (especially if you don't want to hurt yourself)

Then do this 7-8 times:
20 seconds AS HARD AS YOU CAN - imagine you're running for your life.
10 second rest

Repeat. Should only take 4 minutes when you are first starting.

Cool down - otherwise you'll just die. Stretch, or you'll feel terrible.

Keep this in mind - as it says above, once the athletes could do more than 9 sets, they made them go harder - in other words, once you can do it 9 times, you're not running/biking/whatever hard enough. You should only be able to do this a few times.

Warning: this can be dangerous in certain populations. Enjoy!

lol nice first post. very informative

Holy sh!t, no joke this is what happened.

I did that workout above last night, but i was sprinting not bike. Anyway, i only did it 6 times and on the 6th go i fell to my knees and threw up! i know pretty gross, but after it felt good - coz i worked so hard. Thats the hardest ive ever pushed myself physically before!

But, i know for next time, to lower the intensity just a noch so i can get 9 out, and not throw up lol.

Good work, Tim...

Actually, in most of the original studies, they did use a bike. Your body will probably get used to it, too. And you don't have to do it nine times .

Good luck!

Ill keep to 8, coz i managed to do that. But dam im sore!

hiit was around long before tabata, sprinters have done it for years.
i am very familiar with tabatas work but he was not the inventor of hiit.
and hiit is interval training its just that the intervals are more intense.
fartlek is another form of interval training that has been around for over 25yrs.

Sorry for reopening the old thread but the sticky at the top of the forum advises 1 min sprints then 2 min walks etc for 10-15 min, yet this theory claims 20 sec sprint 10 sec rest for a total of 4 min.

Someone please advise me on what method is the most effective?
I can't seem to get a definate answer around here, is this thread divided by these two completely different theory's?

I assume the harder you try the better the results. It doesn't matter how long you do it. You really can't go all out on long distance though since you have to pace yourself. Better to go all out and see how high you can get your pulse. Than let it climb down and do it again. Do this as many times as you can without burning out.

I think you will find at least a dozen different opinions about what is the most effective interval lengths for HIIT in any forum. Like any exercise regimen, what is optimal may somewhat depend on what you are trying to accomplish, your present state of fitness, your genetics, and what you psychologically are prepared to do on a continuing basis.

No one can sprint all out for more than about 15-30 seconds. Look at the difference between the guys who hold world records in 100 meter sprints and 400 meter runs. The 100 meter sprinters are large muscled guys and the 400 meter guys are slim. Why don't the 100 meter sprinters just keep sprinting for 400 meters and set new world records that are just 4 times the time of a 100 meter sprint? Because even the best in the world can't sprint all out for more than about 100 meters. So I would argue that if you truely want to do a HIGH Intensity Interval (an all out 100% sprint), it must be much shorter than 1 minute. I like 100 meter sprint interval and then walk or slow jog back to the start, and repeat. I find it too hard to look at a time piece when I am sprinting all out.

Of course, in the end, any exercise is better than none and the best exercise is the one YOU will do consistantly for the rest of your life!

So what's stated is that not only does it improve anaerobic capacity (which would help for a 55m or 100m runner), but it also improves aerobic endurance more then long distance does? I did HIIT for like, 2 weeks, but even then I saw a difference in how I look. So if you want to increase aerobic endurance, you would want to start off with an HIIT program?

this one..20 seconds hard out and then 10 seconds rest is a good idea for people who do not have much time to do something. I don't agree with the sticky thread because I think thats overtraining whoever posted the sticky. no one can sprint 1 minute total. I can see jogging for 50 or 40 seconds and then sprinting for 10 or 20 seconds.

When I go back to school next wednesday, I want to try sprinting the curves and jogging the straight-aways on the track and sprint each curve 8 times at the most to make I can sprint at around 18-20 seconds the curves or straight aways and my goal is to get it to 12 seconds or even 10 seconds for the curves or straight aways. I am training for soccer and I need something like this.

I will keep the 4 minute HIIT in mind when I don't have much time to do the other.=)

This thread definitely has 2 points of view. 30secs to 1min sprint vs 10-30sec sprint. I have been doing the longer sprint with decent results, especially in my cardio health (I rarely get winded anymore, before I would winded walking up a flight of stairs). My fat burn is not where I would like it to be.

I check out the 10 sec sprints and report back.