lately i have been reading alot about HIIT v ss-cardio but most of the studies are based on low intensity ss-cardio not higher intensity ss-cardio.
alot of the guys on other sites i visit seem to be coming around to the point that higher intensity ss-cardio burns more fat than HIIT.
this was a good point made by this guy called mark in answer to this question
EPOC is said to be in effect for many hours (24+?) after a HIIT session.
.
It depends on your definition of EPOC, but yes, most of it occurs within 36hours.
But there's 4 distinct seperate parts -
1. Glycogen replacement - that will occur within 4-8 hours, especially if you eat some carbs.
2. Nerve damage repair - usually within 36hours
3. Muscle repair - usually within 36hours.
4. Muscle growth - peaks by 36hours, but could take upto 7 days.
During (1) glycogen replacement, yes you have an elevated heart rate and raised body temperature. The 'post-exercise oxygen consumption' (EPOC) is because oxygen is used to break fat into glucose, then used to replace glycogen stores.
But your heart rate can be raised due to eating, heat, stress etc, so its hard to judge your EPOC from it.
The other part 2,3,4 are not strictly EPOC but thrown in the wikipedia definition, and they do not raise heart rate.[ actually to be accurate, (2) nerve damage does raise resting heart rate a few beats, and that's how you can tell if your overtrained i.e. you wake up with a raise heart rate meaning nerve damage exists]
If I -
- burned 200calorie's HIIT, but all glycogen no fat during exercise
versus
- 200calorie's from fat during cardio
Then there are no 'extra' calorie's burned in EPOC phase 1. glycogen replacement because i'm simply delaying the use of my fat from during the exercise, until after it.
The only 'extra' potential is 2,3,4 i.e. muscle repair and growth, mostly of fast twitch fibre's.
I believe this is bit of a widespread misunderstanding being spread about HIIT, the only added benefit in terms of fat loss is the potential for muscle growth and resources used in muscle repair, not the fact it delays burning of fat until after exercise.
To be honest, you won't burn as many fat calorie's doing HIIT as cardio in most cases. A 20minute HIIT will burn around 200-300 calorie's if done intensely. Whereas a 40minute cardio will burn around 600-700.
The hope is though that HIIT will cause muscle reapair/growth which increases metabolism, burns exra calorie's above cardio - just as per weight training.
That is definitely true, and anyone new to HIIT should get that effect for the first few months, but then it will slow down. That assumes you EAT ENOUGH and REST ENOUGH to allow muscle growth, which from what I see, most people aren't.
So why do studies show HIIT burning more fat?
There's only a couple of studies, and the methods and results in detail don't show that infact. The main point was HIIT is more TIME efficient i.e. your burning fat faster, but not necessarily more of it, this will come out later as papers are peer reviewed more.
Also most studies are only measuring this 'initial effect', when the quick gains are made.
I'm not saying HIIT is no good, I'm just pointing out people are misunderstanding and hyping these studies and EPOC way beyond what the results show.
I know from myself, HIIT does work for fat loss, but cardio works just as well if not better if done intensely( not low intensity as per HIIT studies).
Edit: just wanted to add, that weight training is the ultimate HIIT !! doing 20reps on the squat at say 60% max weight versus sprinting is basically the same in terms of physiology. There is an important difference though to do with speed of movement.
alot of the guys on other sites i visit seem to be coming around to the point that higher intensity ss-cardio burns more fat than HIIT.
this was a good point made by this guy called mark in answer to this question
EPOC is said to be in effect for many hours (24+?) after a HIIT session.
.
It depends on your definition of EPOC, but yes, most of it occurs within 36hours.
But there's 4 distinct seperate parts -
1. Glycogen replacement - that will occur within 4-8 hours, especially if you eat some carbs.
2. Nerve damage repair - usually within 36hours
3. Muscle repair - usually within 36hours.
4. Muscle growth - peaks by 36hours, but could take upto 7 days.
During (1) glycogen replacement, yes you have an elevated heart rate and raised body temperature. The 'post-exercise oxygen consumption' (EPOC) is because oxygen is used to break fat into glucose, then used to replace glycogen stores.
But your heart rate can be raised due to eating, heat, stress etc, so its hard to judge your EPOC from it.
The other part 2,3,4 are not strictly EPOC but thrown in the wikipedia definition, and they do not raise heart rate.[ actually to be accurate, (2) nerve damage does raise resting heart rate a few beats, and that's how you can tell if your overtrained i.e. you wake up with a raise heart rate meaning nerve damage exists]
If I -
- burned 200calorie's HIIT, but all glycogen no fat during exercise
versus
- 200calorie's from fat during cardio
Then there are no 'extra' calorie's burned in EPOC phase 1. glycogen replacement because i'm simply delaying the use of my fat from during the exercise, until after it.
The only 'extra' potential is 2,3,4 i.e. muscle repair and growth, mostly of fast twitch fibre's.
I believe this is bit of a widespread misunderstanding being spread about HIIT, the only added benefit in terms of fat loss is the potential for muscle growth and resources used in muscle repair, not the fact it delays burning of fat until after exercise.
To be honest, you won't burn as many fat calorie's doing HIIT as cardio in most cases. A 20minute HIIT will burn around 200-300 calorie's if done intensely. Whereas a 40minute cardio will burn around 600-700.
The hope is though that HIIT will cause muscle reapair/growth which increases metabolism, burns exra calorie's above cardio - just as per weight training.
That is definitely true, and anyone new to HIIT should get that effect for the first few months, but then it will slow down. That assumes you EAT ENOUGH and REST ENOUGH to allow muscle growth, which from what I see, most people aren't.
So why do studies show HIIT burning more fat?
There's only a couple of studies, and the methods and results in detail don't show that infact. The main point was HIIT is more TIME efficient i.e. your burning fat faster, but not necessarily more of it, this will come out later as papers are peer reviewed more.
Also most studies are only measuring this 'initial effect', when the quick gains are made.
I'm not saying HIIT is no good, I'm just pointing out people are misunderstanding and hyping these studies and EPOC way beyond what the results show.
I know from myself, HIIT does work for fat loss, but cardio works just as well if not better if done intensely( not low intensity as per HIIT studies).
Edit: just wanted to add, that weight training is the ultimate HIIT !! doing 20reps on the squat at say 60% max weight versus sprinting is basically the same in terms of physiology. There is an important difference though to do with speed of movement.