Afterburn effect from HIIT - what to expect measuring calories

[Kevman]

When doing HIIT such as cardio on elliptical cross trainer can anyone tell me their experience for calories burnt after the exercise? From reading I was expecting to see a noticable increase in calories for some time after the exercise which I didnt see.

Also if doing HIIT with weights instead, does fitbit record increased calories burnt after the exercise?

Using a Charge HR I tried the 20 min, 8 interval program (Sprint 8 on Vision Fitness machine) for the first time today but saw no afterburn (increased calories burned after the exercise) over and above a low intensity cardio workout (again 20 mins). 

Note: I peaked on average at 92% (max heart rate) on the intervals so I think I was trying hard enough.

[Heybales]

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@Kevman wrote:

When doing HIIT such as cardio on elliptical cross trainer can anyone tell me their experience for calories burnt after the exercise? From reading I was expecting to see a noticable increase in calories for some time after the exercise which I didnt see.

Also if doing HIIT with weights instead, does fitbit record increased calories burnt after the exercise?

Using a Charge HR I tried the 20 min, 8 interval program (Sprint 8 on Vision Fitness machine) for the first time today but saw no afterburn (increased calories burned after the exercise) over and above a low intensity cardio workout (again 20 mins). 

Note: I peaked on average at 92% (max heart rate) on the intervals so I think I was trying hard enough.

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First, separate what HIIT really is from what the name has been slapped on incorrectly.

There is no such thing as HIIT with weights. If you are doing weights, you are just doing a type of lifting program.

HIIT is High Intensity Interval Training for some cardio activity you would normally do as long and calm.

You don't do that with weights.

Second, HIIT can rarely be done on machines correctly, though elliptical could be a tad better - because you can't ramp up to your full effort fast enough for a brief period (15-45 sec) to actually make it HIIT.

Third, HIIT EPOC is only a tad long, that's where HR would be elevated.

The rest of the increase comes from repair from the activity over the next day.

And that's because HIIT is as close to lifting as you can get for those that want to do only cardio.

But the method of doing it causes the same micro tears, though not as many, as lifting, requiring the same repair 24-36 hrs later. That repair is increased metabolism - which won't show up in increased HR that is going to show up to be counted as increased calorie burn on a HRM.

They use step based below exercise level, so that effect would never show up.

Now, your resting HR may be a tad higher, like when sleeping.

But again, calorie burn for so low a HR isn't based on HR, but calculated on age, weight, height, gender.

[Kevman]

Thanks Heybales for your comments.

My intention wasnt to slap together a name and make the meaning unclear. I did re-check definitions after your post and there are many websites which refer to HIIT to include weights and strength conditioning. Most apply for cardio so I'll keep with your defintion.

Getting back to the main points. Thanks for clarifying HIIT EPOC vs repair that helps. Also your comment about repair and metabolism makes sense. I now know that fitbit only counts calories based on HR which I am guessing is the same for most activity trackers. I happened to come across an article from the Director of Research at Basis (a competing activity tracker) and he referred to a metabolic cart as the best measure of energy by analyzing oxygen and carbon dioxide concentrations. Knowing that activity trackers cant measure this, the best that can be done is to use use an algorithym. So long story short, it seems metabolism and therefore calorie count cant be measured.

[Heybales]

Believe me, I know that wasn't you putting the name on there - it's become a fad ever since tabata made it big, and confused things.

And it is indeed being slapped on all kinds of things that have existed for ages, and were always done with the scheme of do some hard reps, rest, do them again, ect.

By that definition some use, general weight lifting would be HIIT, which it isn't.

The BodyMedia devices that had sensors that measured heat, if the sensors worked well for you (about 50% success on that it seems), could see the increased heat output of repairs and gave higher calorie burn.

The studies that showed HIIT had same afterburn effect as lifting used a metabolic chamber, where the participants had to stay for 3 days having all their heat output measured.

Even the metabolic cart would not be able to be successful with afterburn, because it also sees changes in oxygen carbon dioxide output after you eat, which also does change it.

So indeed an unmeasured aspect of calorie burn.

[reuel]

there IS such a thing as HIIT with weights. try doing fast t-push ups with 10-15 lbs dumbbells. try doing push-press for 1 minute with a 30 pound bar as fast as you can. try doing jumping lunges with 10 lbs weight in both hands. if that doesn't get your heart rate pumping or you achieve muscle failure from those weights, you are either female or you have very low muscle mass (to which you'd adjust the weights used).

anything aerobic can be HIIT, as long as it gets your heart rate moving and you won't achieve muscle failure before you are exhausted.

as to answer your question: i personally do not believe in that "after burn" effect. its a gray area and accounting for it would only end up with you overestimating your exercise calories. i do not know if it is for real, or just some pseudo-science used to promote different HIIT versions as "better," all i know is that its better to underestimate exercise calories than overestimate them.

[Kevman]

Thanks reuel. I originally took the research around afterburn as correct. After your comments I read a bit more about it and found the following:

1. I cant measure the afterburn for myself
2. Research proof is controversial
3. Amount of afterburn is overhyped - I do believe there is an additional gain but small so guessing 15% (I dont believe double or more). Like you I wouldnt count it personally.

With so much uncertainty I think incorporating a balance of HIIT cardio, long slow cardio and weight training would cover all bases rather than take the idea that a lot of HIIT cardio is going to be a "silver bullet" for loosing fat. Also I'd seen a numerous articles that refer to the importance of controlling food intake having a far greater effect than afterburn which I strongly buy into.

[reuel]

i pretty much agree with your post above kevman.

as for my experience with HIIT ... i got overtrained with it. as a martial artist i am inclined to love HIIT because that kind of training is very similar when you are sparring, and competiting in tournaments. i was also taught to "give it my all" and "never quit until i pass out from exhaustion." its basically the mentally of crossfit before crossfit became a thing.

i have to say, it was bad. at a certain age and fitness level, i could handle that training, but when i hit my 30's ... injuries took longer to heal, muscles took longer to repair, i realize that i totally lost my passion for working out, thanks to too much HIIT.

currently, i know better, and i am lot nicer to myself ... i only train max HIIT once a week, as opposed to 4x a week. you definitely have to mix things up, especially if your body is not that of an athlete (which is and was my case).

and yes, losing fat is all about wht you eat. you cannot outexercise a bad diet. back when i was doing crazy HIIT routines, i could last 18 rounds in the ring - 3 mins fighting and 1 min rest. i had very good cardio for my size (5'7, 190 lbs) ... but i was fat lol not much muscle on me. i was a strong fat guy. it was good and all, but my weight was beginning to take its toll on my knees, so i eventually had to stop a lot of crazy routines (burpees and the like)

[DominicJ]

A calorie is a unit of energy.

Energy cannot be created or destroyed.

"Afterburn" needs to be sending this energy somewhere, or it cant exist.

HIIT is the absolute worst way to burn calories, simply because it cant be maintained for long enough.

You will burn more sprinting for 15 minutes than you would jogging for 30minutes, but you cant sprint for 15minutes, you cant sprint for 5 minutes.

If calorie burn is your goal, work for as long as you can, as hard as you can.

Thats very different from work as hard as you can, as long as you can.

[reuel]

dominicJ, there is no best way to burn calories.

it depends on the individual. my female friend loves doing those slow, not getting the heartrate above zone 3, stuff (3 hour runs, endless zumba sessions and what not). while i love doing the bootcamp, circuit, martial arts stuff that is basically HIIT.

she cant do what i do, and i cannot do what she does. we both burn enough calories (obviously, i burn more cause i am overweight, while her body fat levels are low enough where her abs are almost sticking out).

i have burned 1,500 calories in martial arts training, and i have burned 1,500 calories doing a 15K run. which is the best way to burn calories? both. i just like martial arts training more than running. besides, my knees hurt running that kind of distance.

[DominicJ]

I find it very hard to believe you quickly burned 1500 calories at max effort, but open to conversion, what were you doing and for how long?

[Heybales]

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@Kevman wrote:

Thanks reuel. I originally took the research around afterburn as correct. After your comments I read a bit more about it and found the following:

1. I cant measure the afterburn for myself
2. Research proof is controversial
3. Amount of afterburn is overhyped - I do believe there is an additional gain but small so guessing 15% (I dont believe double or more). Like you I wouldnt count it personally.

With so much uncertainty I think incorporating a balance of HIIT cardio, long slow cardio and weight training would cover all bases rather than take the idea that a lot of HIIT cardio is going to be a "silver bullet" for loosing fat. Also I'd seen a numerous articles that refer to the importance of controlling food intake having a far greater effect than afterburn which I strongly buy into.

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3 - Wow, can't believe you found claims of double or more calories, that is exaggerated.

Now, from a good lifting workout, which doesn't actually burn that much during the actual workout, that increased metabolism from repair happening for next 24-36 hrs can indeed equal the amount you burned. But double there would be too much too.

But you gotta have a great workout and really tear it up. Do it tired, failed mission. Don't allow recovery, wasted lifting session.

HIIT being cardio means you are burning more during the workout, and you aren't causing as serious of repairs as lifting would cause, so that increased metabolism while decent by itself, is a smaller % of the workout calorie burn.

HIIT has become a fad just like the fad of doing cardio in the fat burning zone was prior.

Both are valid workouts for specific reasons, and both were misapplied and taken to extremes.

Actually, if you only had 20 min, and were not training for endurance cardio event (a long race), and were purely about burning the most calories, doing that 20 min as hard as possible would be best approach.

But even day after day of that is rather stressful on the body, and especially when in a diet when recovery is impaired already.

It would be a terrible workout proceeding or following a lifting day using the same muscles, as it would negatively impact the lifting.

HIIT is usually done just 1 day a week by pro's for their cardio training, because it is a huge stress on the entire system, and deserves a recovery day afterwards.

And that's where the fat-burning zone comes in to play, because that HR zone was called Active Recovery before it became fad - a great workout zone to get blood flowing and aid repair and recovery - while being active.

And indeed - having the diet in control is going to be more helpful than all these little things that help burn fat a tad better. Actually, trying to do all those things usually leads to mediocre workouts that don't accomplish as much as they could.

Lifting is going to be the best one, not for the increased metobalism, but for the change to body, and what is exposed when the fat does come off.

[DominicJ]

"Actually, if you only had 20 min, and were not training for endurance cardio event (a long race), and were purely about burning the most calories, doing that 20 min as hard as possible would be best approach."

Which weould fit the brief of working as long as you can, as hard as you can.

If you have 20 minutes, go as hard as you can for 20 minutes

If you have an hour, go as hard as you can for an hour

Dont go as hard as you can for 5 minute, rest for 10, and repeat (or 30 seconds with a 10second rest or whatever)

[reuel]

DomJ: i was 200 lbs at 5'7 ... it was a boxing program - its a mix between boot camp style HIIT, sparring, ring work, foot work and punching drills, skill work, etc.

it was measured by my polar HRM. i believe it was 2 hours or so. there's probably a 10-15 minute break after a program ends. it was insane, and it was around 1,300 calories, not 1,500 which i used as just an example. and yes, it is usually hard to believe. what i do is not even half of what someone getting ready for an amateur bout does - although to give credit to myself, i am a very hard worker compared to most who train in our local gym.

a guy who is taller and heavier than me could probably burn way more calories. the thing is, after a few rounds of doing max effort, your heart rate takes awhile to go back to normal. that is the reason why those figures show up in my HRM. there was a time i reached 110% of my max HR. it does not happen all the time, but it has happened more than once. most people just reach 100% of their HR and call it a day. the thing is, you have to keep reaching it several times a session to really reach that amount of calorie burn.

now, i do not recommend that training often. once a week is good if you are tough. once a month if you are normal.

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re your last post: calorie burns are not everything. lifting weights does not burn as much calories as running, but lifting sure is worth it. HIIT may not burn as much calories at a given time as running at a certain pace, but you surely would be more explosive than the guy who can do 80K marathons.

if you think HIIT is a waste of time, then i respect that. it is your opinion. your goal seems to be working out for the sake of burning calories.

[DominicJ]

I don't think hiit is a waste of time (I do think its a bit faddy but that's by the by)
I also lift, not massively at the moment but I'm getting heavier

But, your last sentence nails my point exactly.
If you want to lose weight, sustaining a steady pace is the best way.

[James_R]

When I run HIIT, I tend to find the calorie burn similar to a prolonged workout (when worked out via arithmetic, don't think FitBit actually differentiates between basic cardio and HIIT, it is essentially a glorified pedometer after all), but I find the easiest way to look at it is in terms of zones, e.g. aerobic, anaerobic, etc. and tailor HIIT to burn and steday cardio for endurance and stamina. 

The concept of HIIT with weights however, I can honestly call that a reckless and dangerous idea. Steady reps is the key to any resistance program, by all means superset and work to failure, but under no circumstances should you rush sets. Basically it goes one of two ways, you fast rep light weights to no effect, or you seriously injure yourself on heavies due to bad form and uncontrolled motion. 

[Kevman]

Funny comment about the never quit until I pass out 

Interesting to hear about your experience with injury doing too much HIIT. Unfortunately just hit 40 and I want to build lasting exercise habits so I am putting everything in place that ensures consistency. That includes avoiding injury and keeping motivated - I just saw a post on this thread that mentioned doing it one a week which sounds like a good idea. BTW I would consider myself reasonably healthy and averagly fit but of course wanting to improve that.

[josephz2va]

I have yet to hit my HIIT. So I'm taking it as a step by step level build up. Some can't take 0 to 190 BPM immediately. I know my trainer wants me to do that, but it's like trying to go faster than the elliptical machine can handle at level 8-15. Aggressive enough that you can break the machine or take a trip to the ER.

I'm using the elliptical machine on HR Interval rather than the aggressive approach. 2 minutes 129, 2 minutes 147, down and up for a total of 10 minutes. After my warmup of 129 to 147 10 minutes, I go up to 147-160 10 minutes then 158-170 as long as I can tolerate level 6 resistance until I can go 180 and 190 with level 15 resistance.

Octane Fitness Pro 3700 elliptical trainer.

I haven't seen 1500 calories during my exercise. It would take a massively long time. My current effectiveness is 565 calories in 47 minutes.

[DominicJ]

My output is pretty similar to yours, I can manage 10calories per minute plus another hundred

So I can do 300 in 20minutes, but require a break after that, or 600 in 50 minutes, and then need a break (or have gotten bored and want to go home)

1200 in 2 hours is pretty high but its not shockingly so.

T25, Insanity and so on are all time limited excercise regime, which HIIT is great at.