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Interval Training on an Empty Stomach


Quick question.. Is is alright to do interval training in the morning on an empty stomach 4x a week for 20 or so minutes?


I did that for about 3 months and lost like 24 pounds, with a modified diet of course. There is a tad bit of a problem though and that is the fact that I guarantee you will lose muscle, and I mean quite a bit. I would honestly say I believe I lost at least 12 pounds of muscle doing it and will never do it again.


just because of the intensity? do you suggest then steady state?


I know I cannot do HIIT 4x a week; I just can't recover fast enough.

Whether or not you should use HIIT or steady state cardio to burn off fat depends on how lean you are. That's what I think, anyway.


hopefully we don't end up arguing about hiit vs steadystate

ponce, you're saying leaner = less hiit?


It's legal so in that regard it's alright.

I've never had much success with it because I can't work with the same intensity as I can if I eat something. The EPOC is much lower and my body returns to its resting state much sooner.


I'd strongly recommend against doing interval training on an empty stomach unless your goal is to lose muscle!
I'd go with low intensity training(slow cycle or jog) on an empty stomach, or else intervals after an adequate amount of food(at the very least one good meal an hour or so beforehand, and horse down some BCAAs).


Interval Training relies heavily on glycogen and is very taxing. Doing this fasted would most likely burn muscle mass. Would you weightlift in the morning fasted?


You wouldn't have anything to puke up.

If you are worried about muscle loss (as in you are already quite lean) then it isn't hard to set the alarm a little early, scoff some whey shake by your bed and some BCAA's. then go back to sleep for another 30-40 mins before waking up to do burpees, sprint and throw sand bags.

If you really hate life and early morning eating then you could just go for a light jog and or maybe a power-walk. your body might not even notice that kind of well-sold, fashionable "lifestyle habit." You would even be able to feel great about eating a nice low fat muffin and a skinny latte afterward. Be sure to get the soy milk, I hear it helps with menopause.

In other news: If you are over-fat and looking to lose it then doing the intervals is better than not doing them. Besides if you eat right afterward and make sure you get good meals throughout the day and a some fats and animal protein before bed then your body should be keen to keep muscle well enough. testosterone is also at a high point right upon waking and will likely help prevent muscle wasting to some extent if your diet is strong and consistent.



What is your priority right now? Quick fat loss? Take some AA's before doing your intervals to help protect your muscle. When I'm going high gear for fat loss I like to do HIIT and SSC 6 days a week, alternating days as well as skipping any form of cardio altogether the morning after a leg day.

This tears up a lot of subcutaneous fat I have and while I have seen guys burn up their muscle while doing this, I seem to hold onto my muscle pretty tightly, so there seems to be some individual traits here.

Follow a solid diet and take some AA's before hand and get in a quality meal as soon as you're finished. A lot of guys on this forum are terrified of losing muscle just like a lot of the skinny guys here are terrified of putting on any fat.

If you're interested in being balanced then you're eventually going to have to compromise and give up a little muscle and at other times take on a little fat. It's your call, hope my opinion helped.


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If your goal is fat loss do it. Here is an older article which touches on it:


"Assuming you want to be super-shredded sooner rather than later, you'll need to do some steady state cardio in addition to the HIIT. Since you're probably already doing steady state cardio, let me ask you a second question: do you do your steady state cardio first thing in the morning before eating breakfast? If not, then you should be."

I.E. it depends on your goals.


That suggest that your should consider fasted steady state cardio, not fasted HIIT. They're two different things.


It really depends on your definition of HIIT, and your definition of intensity.

I dont believe that fasted cardio of any type will cause muscle loss solely due to the fasted cardio. But I do believe there are a bunch of factors that can make any form of training swing either way.

Theres a delicate balance that must be maintained between intensity and volume(duration) as well as recovery. Intensity and volume are inversely related to eachother, and the greater your recovery, the greater intensity/volume you can handle.

For example:

You could do 45 minutes of fasted cardio and lose minimal muscle, or you could do do 25 minutes of fasted cardio and lose a lot of muscle. The big difference would be the intensity.

There are a lot more factors than just intensity and volume though.

Quality of nutrition
Maintanence or improvement in resistance training sessions

Ive been doing fasted cardio for about two weeks now, and dont think ive lost any muscle. I will say that im not trying to lose weight though, so before my evening resistance training session, I make sure to eat enough to start gaining muscle again. But I have done some HIIT sessions fasted with no problems. But they aren't nearly as intense as they would be later in the day in a fed state.

What are your lifting stats? as well as physical stats?


You're right I misread, my mistake. After rereading more closely again however, I did notice that he does mention that the timing for HIIT doesn't matter as much making it seem to me as though it would not hurt to do them in the morning before breakfast if fatloss is your goal...and that is what I've been talking about.

Anyone else notice that the thread starter hasn't posted again?


I'm starting to believe that you should work a mix of energy systems if you want to get lean.

And yes, I think the more muscle you have, the more efficient your body is at handling that tissue, which to me means not only efficient at maintaining that muscle but also building it up and breaking it down. "Handling" muscle tissue, if you will.

I have noticed this with friends of different body types when we've discussed leaning out and watching each other's protocols. I'm definitely no expert here, though, just my thoughts.

Actually, what I just said regarding muscle tissue would tie would apply to fatty tissue as well if what was said in that thread in Alpha (Things I Can't Prove) regarding taking a bit of oil before a session of cardio to stimulate fat loss.

Again, I'm not the one with degrees...


I would only do steady state cardio fasted myself. I haven't been able to do anything too intense fasted without feeling like I was going to die and having a hard time recovering.

I do fasted runs every morning and sprints 4x a week after work. It seems to keep me pretty lean.


Watch out for those stalkers Debra :slightly_smiling: