This seems to be #1 in the misunderstood category right now so I am posting this sticky to clear things up on what exactly HIIT is but not getting to science heavy. Hopefully this should put some confusion to rest.

What is HIIT?

High Intensity Interval Training is a type of interval training that is broken up into 2 segments. An extreme high bout of intensity followed a low bout of intensity.

What are the Benefits?

-Increasing your VO2 Max oxygen intake (in short increasing lung capacity and use)
-Lowering resting heart rate
-Longer increase of metabolism over more extended periods of time
-High levels of energy used in a single training session
-Better protection of muscle tissue over standard aerobic practices

The list goes on.

How does it work?

When you are doing a session of HIIT correctly you start with warm up of at least 5 mins to get your body prepared for the extreme work it is about to undertake. I recommend not only warming up by walking, but prior doing some dynamic stretches to prepare your body for the impact especially if doing the training in walk/sprint intervals.

When the first interval kicks in you need to go at an ALL OUT SPRINT for 10-20 secs. Unless you are a highly trained athlete you will not (if doing it correctly) be able to do more than this, period. This isn’t running, this is sprinting or better put running for your life as hard as you possibly can. I have seen people fall flat on there face before. You are working at a 85 to 90% of your heart rate. You cannot physically move and go much higher than this. I see a lot of people trying to time themselves or their heart rate during these sprints, it isn’t possible. You can’t do anything else other than pray and run for that 10-20 secs.

After that sprint you will then walk at a very light pace (you really have no choice but to) for 1 min or even a little longer depending on what you need for recovery time when you are beginning this type of training. After 1 min you will then do it again for 10-20 secs.
You will repeat this for a MAXIMUM of 15 mins. Most people however starting out will do this for about 10 tops.

After you are done with your interval sessions you will then cool down your body for 5 mins at a light walk pace.

Here is how a normal HIIT schedule breaks down

Warm up-Dynamic stretches (lunges, walking kicks, side bends, toe touches)
Warm up-5 mins walk to brisk walk
10-20 secs-Sprint
1 min walk
10-20 secs-Sprint
1 min walk
10-20 secs Sprint
1 min walk
10-20 secs-Sprint
1 min walk
10-20 secs Sprint
1 min walk
10-20 secs-Sprint
1 min walk
10-20 secs Sprint
1 min walk
10-20 secs-Sprint
1 min walk
10-20 secs Sprint
1 min walk
5 min cool down
Post workout Static Stretches

How intense is this workout?

EXTREMELY intense. After a real HIIT session you will feel light headed, dizzy, you may even throw up, I know I have. This is not a normal aerobic session, infact this is about increasing anaerobic threshold, this is nothing like what most people have done before, even those who claim to do HIIT.

Who can do HIIT training?

Not everyone can start out doing this kind of program. This is again a very intense and extreme program. It may take you a very long time to get to HIIT.

What can I do if HIIT isn’t for me?

You can do interval training at a moderate level or other style of cardio like Steady State.You do not have to do HIIT to lose fat, it is merely one option. However it is an extremely powerful option not only for fat loss but for health.
You can also do interval training and throw in one or two sprint in your program and build up from there. Building up to this type of program isn't to difficult, it is much like weight training. You have to have bouts of increasing your intensity.

This sounds dangerous, is it safe?

If done properly and with the right conditioning yes it is very safe. I highly recommend though being cleared by your doctor before engaging in new exercise activity.

I have read about what HIIT is and this isn’t it. Do you know what you are talking about?

Yes, but if you don’t want to take my word for it you can read these studies and decide for yourself.

Medicine & Science in Sports & Exercise - Abstract: Volume 28(10) October 1996 p 1327-1330 Effects of moderate-intensity endurance and high-intensity intermittent training on anaerobic capacity and [spacing dot above]VO2max.

http://etd-submit.etsu.edu/etd/these...d/king0417.pdf

Nice Post Leigh.

I will add for any of those who are reading this and may be conditioned enough. You can do whatever ratio of high/low intensity you like. Actually, it is good to change things up after a bit.

Yeah! Now I know what ya'll have been talking about for the past month!

Thanks for the post!

Thanks for clarifying this....do you think you could post the same info, same format (benefits, how it's done, etc.) for IT and LISS as well??

I guess at this point in my journey I have begun Interval Training. I hope this will work for weight and fat loss for me for awhile before I bump it up to try HIIT. A post like this on the other forms of cardio workouts would help guide me....

(in my best Borat voice) Verrrrry niiiiice Leigh. I like! Is good!

Personally I have been warming up by jogging a mile, then going a little longer on the sprints... 200 yards, but I don't know how long exactly it takes me. Given my current conditioning and age, I'm guessing between 25-30 seconds, at least at first. All I know is that I hit it balls out as if I were running a 40, then I briskly walk or lightly jog the rest of the way around the track, which should take me about a minute or a little more, then I fire it up again. Holy hell man, I'm lucky to get 5 sets in, and those last two feel like I have concrete blocks tied to my feet, and that's with me being a sprinter in track all my life even for a college team, I've met all my weight loss goals and then some, and I either go cycling for 15-25 miles, run a 5K, or do 1,400 jump rope reps along with a circuit workout nearly every day. Yet, considering a 30 second sprint and 60 second walk/jog 5 times... that's 7.5 minutes, half of the typical 15 minutes that you often hear about with HIIT workouts.

A friend of mine caught wind that I was doing this and he tried to mimick my workout without me knowing about it and he injured himself, he can't hardly run at all right now, and he was in at least decent shape, we go mountain biking and running and snowboarding together, and he simply needed to lose 20 pounds.

So, truly no offense to any of you who have been preaching HIIT, but these experiences are exactly why I have questioned preaching it to this particular crowd, because it's a hell of a lot more intense than most people realize, which means many will be thinking they're doing it right but actually aren't, or else they'll do like my buddy and will in fact go balls out but they'll end up injured because they're not ready for it.

Agreed.

List above is merely a basic program style, you can do all kinds of things with HIIT. It also does not have to be just running, you can use ellipticals, bike, cones, the list goes on.

Here is an article on cone usage from a great trainer who posts on this forum some as well as others.

Alterna-HIIT by Jonathan Fass

I will put something up this evening

Yes I think you are right and it is exactly why I posted it. I believe in optimizing training programs, but I also believe in working towards that in a smart and healthy manner. Just as you shouldn't go into a gym and start squatting your body weight without gradual progression the same is true for this. Hopefully this will help people understand that.

I thought I should also add that one of the greatest benefits from an athletic perspective, as crazy as it sounds, is that it trains your body to buffer hydrogen ions, which is a byproduct of lactic acid, and they slow you wayyyyy down, your muscles turn acidic and start shutting down when they are formed.

I'm glad you mentioned forms other than running. Just for variation, I've done HIIT using the elliptical, stationary bike, rowing machine (even tried it with a jump rope once - will never be that stupid again!) Every method left me facing the question at the end "do I throw up now or later?" - so I was hoping every method was equally effective - but I'm glad you said it.

I haven't ever felt really dizzy or sick when I am done with my HIIT
program...am I not pushing myself hard enough? This is what I am currently doing....

Treadmill
Walk 4 min at 3.5 mph
Jog 6 min at 6.5 mph
Sprint 30 sec at 8.5 mph
Jog 30 sec at 6.5 mph
I do this sprint/jog cycle 5 times
Then Sprint 30 sec at 9.0
Jog 30 sec at 6.5
Do this sprint/jog cycle 2 times
Then I sprint at 9mph for 1 minute
Walk at 3.5 for 3 minutes

Sorry that's kind of confusing. What if anything would you suggest I change or improvise?

Mine is similar...I call it HIIT, but according to the article is not the true form...but modified, as Steve indicated.

I use my treadmill at a 1.0 incline primarily. Sometimes I up the incline off and on during my sprints to vary it. My workout is somewhat different everyday depending on the incline and the speed...the time however stays the same.

I warm up for 5 minutes at 3.5 mph
sprint for 1 minute at 6.6-7.0 mph
walk at 3.8 mph for 2 minutes
I continue the sprint/walk pattern until I have 5 minutes left...slow down to a cool down of 3.8-3.0 mph for that last 5 minutes.

I need to add this to my program on my treadmill as I find it most annoying to have to continue to deal with the buttons...hehehe.

Beth

I hit 10.0 yesterday during my sprints on an incline 1, but only kept it up for about 15-20 secs since my knee was starting to feel weird. I didn't make myself go over 3 sprints either.

I need to figure out my RHR so I can see if I'm hitting 85-90% of it. hmmm. .I have read the best way to do this is go to a room and sit for about 20 minutes doing nothing and after 20 mins you can get your RHR.. do you have any other ideas?

It's best to take your resting pulse right when you get up -- before you've been running around, drinking coffee, etc.

when I walk I start out at like at 3.2 for like 5minutes then I do a powerwalk at like 4.3 for 1 minute then I do a moderate walk 3.6.-3.8 for 2 minutes then I go back and forth between the power walk and moderate walk I do this for 30-35 minutes.