T Nation

Switching Up My Fasted Workouts?


For the past two years I have worked out at 6 am before work and don’t eat. Not for any real purpose, simply because a) I have no appetite at that time and don’t want to waste calories on food that I don’t want or enjoy, and b) I don’t feel that my performance is affected at all. I typically eat a high carb meal right before bed (nighttime oats ftw).

My activities range from lifting, HIIT cardio, and one long distance run per week (was a cross country runner in hs and it never left me). I work out 5-6 times a week. I am just one of those fitness nuts and love all things fitness- I have no particular goals right now other than being generally fit and strong, though I would love to lose 5 pounds.

Recently one of the guys I train with noted that switching things up and eating before my workouts could speed up my metabolism and help me lose stubborn fat. I have tried researching this on the internet but the conflicting information out there on fasted workouts is frustrating. Wanted to get peoples thoughts, and if I did decide to try eating before my workouts, how much do I need to eat in order to “break my fast”? I.e. is a shake with half a scoop of protein powder and some berries is enough? Not sure how much more I could stomach.


You train fasted with weights and HIIT? This is terrible, horrible, no good very bad form! If you train fasted in the morning, keep in mind you haven’t eaten in like 8-10 hours, now you’re demanding your body to train. What are you using for fuel? You have no fuel in your body! So your body will literally eat its own muscle for fuel if you do anything beyond some easy walking. HIIT training, weight training, these things require glucose (carbs) for fuel. You’re burning your rubber in neutral while flooring the gas pedal. There’s no WAY are you getting your best possible training or results from training fasted, and there’s a very good chance you’re eating away at your own muscle and screwing up your metabolism. If you’re not hungry in the morning, make a shake or just force yourself to eat for a few weeks until your body gets used to eating. The only thing you should be doing before breakfast is some light steady state cardio if you’re trying to lose fat, and even then research shows almost no difference between fasted cardio and fed cardio for fat loss.

I don’t know what information you could possibly find that shows any benefit to fasted weight or HIIT training. Those authors should be tarred, feathered and sent out to see on a slab of ice. You should absolutely be eating breakfast before training.

Try a shake with a full scoop of whey and a banana or two, or banana and some berries. That’s a least a few hundred calories and shouldn’t be hard on the stomach. You really just need to get past the “I’m not hungry” thing, and find something you can tolerate. It really will get easier after a couple of weeks.


I think robstein is exaggerating just a little bit. Eating before training has been proven to improve your performance during training, as well as being muscle sparing, etc. etc.

That being said, every one is different and the human body can adapt to just about anything. If you’ve been doing this for years, then it obviously works for you. The majority of the nutrition literature out there basically says the warrior diet is bad for you and won’t work for athletes - no energy, lethargic, skinny, no strength, etc. A former team mate of mine began using the warrior diet during our pre-deployment workup, basically eating very little during the day and then having a massive refeed at night - and I do mean massive. It was impressive the amount of food this guy could put down. Our schedule consisted of PT in the morning (lifting, circuit work, run/swim, standard tactical athlete package), followed by a physically arduous day on the river slinging ammo and running his gun (.50 cal, so heavy gun and heavy ass ammo) while wearing full kit in 100 degree Mississippi summer time swamp weather. Not only never fell out, but out performed just about every one who was following a ‘normal’ diet. Sample size of one, I know, but it makes my point - every one is different.

That being said, eating something before training would more than likely have some performance benefits for you - if you can tolerate it. I used to drink a shake before hitting the gym in the morning at work, when my schedule changed after 8-9 years of that and I started making myself eggs and whatever for breakfast, it took some time to get used to eating solid food.

If you can swing the cost, I would recommend Plazma. If you don’t want to drink it throughout your workout, just mix one serving the night before and have it on your night stand so you can chug it as soon as you get up. Not too heavy, but a good mix of macros and electrolytes to get you started.


Pretty much. both Rob and boatguy are dead on. It HAS been impacting your performance and recovery, no matter if you don’t THINK it has or not. This answer is pretty well researched both in the gym with real lifters and in the laboratory with scientists. There are some strange freaks out there like boatguy mentioned who could do the Warrior diet, but they are the vast minority and the chances that you are just like them are near zero.

If you absolutely can’t eat a lot, shake with whey protein and something like surge or ignition for a carb source prior to lifting. If you can’t drink it, drink half before starting lifting and then finish the other half during. But absolutely get something in your body before lifting.

Besides which, you will start to get hungry once you start eating. It will take a couple weeks but it will happen.


I’m a fan of fasting, personally, due to the fact I fucking hate eating breakfast.

Fasted workouts will get you lean, but there is one unavoidable fact (which even the most ardent leangains fan can’t deny):

Fasting is not anabolic

So if you want to get lean, then fair enough. If you want to get big and strong, then set your alarm an hour earlier and get some breakfast in ya.


I get up at 5, take about 15 grams of BCAAs and some caffeine and am working out by 5:20. And that’s after stopping eating at about 2:30 the day before (I’m doing an 8 hour feeding window starting in the morning). I can gain mass or get lean doing this.

Your body has tons of fuel, it’s called adipose tissue. 10s of thousands of calories worth. If you are a fat adapted person, you really do not need dietary intake for fuel.

The “NO THAT’S CATABOLIC” crap is completely overblown. Training is and has to be catabolic. If you are trying to turn pro, fine, it matters. If you aren’t it probably doesn’t. And even then many of the biggest most muscular bodybuilders do fasted morning cardio. Again, despite “the sky is falling” people, getting your body to use muscle for fuel is difficult.

That said, everyone is different and there is no holy grail. Total calories and total macros are 99%. So the bottom line is experiment and find something that works for you and is as easy as possible. Don’t change to something that might be a couple % better for muscle gain if it makes you miserable, it is not worth it. If you don’t like to eat before training (and there are some good physiological reasons not to despite what other posters are saying) then don’t. Take some BCAAs or EAAs before training if you’re worried about the catabolism. Or try a little something beforehand and see if it makes your training better. If it doesn’t or if it makes you feel sluggish or
bloated, stop. It’s pretty simple to experiment and find out, but changing what’s working just because somebody mentioned is stupid. If you feel something needs to change then by all means experiment, but eating before training isn’t the “right” way to do things and fasted isn’t “wrong”, especially for fat loss.


Plazma was a god send when I had to workout at 5am.

Easy to digest, easy on the stomach and you decide the flavour.,. Sometimes I wished for coffee flavour, but that is another story.


I train in the morning as well, and can’t handle a lot of food. So just drink coffee mixed with protein powder and some coconut oil. MCT’s from coconut oil will give you energy in addition to the caffeine from the coffee, and the protein will prevent any catabolic wasting of muscle


Robstein wins for emphasis. I have a buddy who has been doing fasted cardio for a year and wonders why he hasn’t progressed in 11 months. I try and explain, I send articles and studies. It is frustrating having the path to progress and watching someone just spin their wheels. I wash my hands of it all.

Boatguy wins for accuracy.

The weight matters or you want to lose it from fat? Losing the weight will be simple, up your fasted cardio or eat less…just dropping the pre bed oats would probably drop 5 pounds in 2 weeks.

If you want it to be fat and maybe even gain a little muscle just adjust your timing of everything. Move your oats to the AM with a protein source. Continue doing every thing else as you were. Replacing all cardio for heavy compound lifts would also be quite helpful.

Yes. There is a superior alternate version to fasted cardio called Semi-fasted cardio. You eat a protein source but no carbs. Your performance will still suffer (but not as much) but your muscles will be better protected.