T Nation

HIIT at Night

Doing HIIT is supposed to help you burn fat by raising your metabolism throughout the day, so would it be a waste to do it at night an hour or 2 before going to bed?

You should post this in the beginner’s section.

But no, I’m pretty sure you burn calories at night too.

A waste? No, just get your cardio done.

I was gonna go jogging but I got all this enery so I figured I’d do something more intense, thanks for the replies fellas.

Interval work is good for the partitioning effect on your macros. If you can sleep at night afterward, then it’s fine. I do my ‘evening’ intervals around 5 or 6 pm, and try to zonk out by 9:30 if I can. Still manage to get at least 2 feedings in before then though.

S

Pretty sure the reason you do HIIT is for positive adaptions with regards to your enzyme pool, specifically acyl-CoA-dehydrogenase (B-HAD) the rate limiting enzyme in beta oxidization. This makes you a better fat burner all the time by increasing the intensity you can work at while allowing lipids to be your primary fuel source [Crossover Point]. Don’t worry though these adaptions have been shown to happen relatively rapidly (within a couple weeks) if you have adequate intensity and volume (10-15 minutes of the high intensity stuff per week).

The raised metabolism is acute at best and really is a non factor when it comes to burning fat. If this was your primary interest a secondary resistance training workout or a form of aerobic exercise would be just as suitable seeing as they have been shown to decrease ones respiratory exchange ratio (RER) with no significance difference between the three modes of exercise.

And really as I am sure you already know, your fuel source will be largely dictated by nutrient availability. The body is lazy and will use whats in the blood first.

[quote]hipbone wrote:
Pretty sure the reason you do HIIT is for positive adaptions with regards to your enzyme pool, specifically acyl-CoA-dehydrogenase (B-HAD) the rate limiting enzyme in beta oxidization. This makes you a better fat burner all the time by increasing the intensity you can work at while allowing lipids to be your primary fuel source [Crossover Point]. Don’t worry though these adaptions have been shown to happen relatively rapidly (within a couple weeks) if you have adequate intensity and volume (10-15 minutes of the high intensity stuff per week).

The raised metabolism is acute at best and really is a non factor when it comes to burning fat. If this was your primary interest a secondary resistance training workout or a form of aerobic exercise would be just as suitable seeing as they have been shown to decrease ones respiratory exchange ratio (RER) with no significance difference between the three modes of exercise.

And really as I am sure you already know, your fuel source will be largely dictated by nutrient availability. The body is lazy and will use whats in the blood first.
[/quote]

The definition of ‘making stuff more complicated than it needs to be’, is this post.