Exercise on an empty stomach?

No, not really. There is some evidence that it burns a TINY bit more, but it's an amount so negligible that it's really not even worth bothering with. And that's in controlled conditions where the experimenter can say FOR SURE that the subject is exerting his/herself equally to when they have a full stomach.

You cannot say that for sure, so the extreme likelihood is that you will not exert yourself as much because you are not properly fueled, and will not only wipe away the possible negligible difference, but actually enter that territory where you're doing worse than you would if you ate.

Properly fueling your body for exercise allows you to reach your full potential during exercise, thus burning more calories and avoiding the unpleasant and sometimes dangerous effects of poorly fueled exercise. These include but are not limited to foggy brain, increased risk of injury, dehydration, and loss of lean body mass.

ETA; Note that the few studies where they found said negligible differences are still being looked over by the rest of the scientific community and may well be disputed anyway.

Nope. Because your body still stores glycogen, you'll first use that at fuel. And most people will fade real fast if their glycogen stores get totally depleted.
The main reason I exercise on an empty stomach is when training intense, you don't have to worry about food coming back up.

A.C.E. Certified Personal and Group Fitness Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition

Somewhat, although it's best to take 5-10 grams Branched Chain Aminos first (BCAA's), to help
protect your muscles so they aren't used for fuel too!

I have suffered a migraine twice after exercising on an empty stomach, which is enough that I no longer do it, so i don't know if it affects my performance.
I do that I feel best exercising about 1-2 hours after eating a small meal or substantial snack, if it's too long since I ate,I feel kind of weak and if I ate too recently, I tend to feel nauseous.
Even if you do burn your food first, the stored fat has to be used at some point if you're in a deficit, it just might be burned later in the day when you're resting and your food's already been burnt off. It's like if a friend gives you a fiver and you buy something for a fiver, it doesn't matter whether you use the friend's money or some from your purse, you have the same amount of money later in the day when you go to buy something else.

http://blog.myfitnesspal.com/the-surprising-benefits-of-exercising-on-an-empty-stomach/

I found this to be an interesting read regarding fasted exercise. But in general I think it's up to personal preference. I think if there was a significant benefit to exercising on an empty stomach then we'd all be doing it and it would have been pushed in our faces by scientists (rather than by exercise guru types).

For me, it depends on the workout. For cardio, I feel better on an empty stomach. For strength, I like to eat before working out. Do what feels best/makes the most sense to you.

I run better on a empty/ very little food, hours after eating.

CoffeeNCardio wrote: »

No, not really. There is some evidence that it burns a TINY bit more, but it's an amount so negligible that it's really not even worth bothering with. And that's in controlled conditions where the experimenter can say FOR SURE that the subject is exerting his/herself equally to when they have a full stomach.

You cannot say that for sure, so the extreme likelihood is that you will not exert yourself as much because you are not properly fueled, and will not only wipe away the possible negligible difference, but actually enter that territory where you're doing worse than you would if you ate.

Properly fueling your body for exercise allows you to reach your full potential during exercise, thus burning more calories and avoiding the unpleasant and sometimes dangerous effects of poorly fueled exercise. These include but are not limited to foggy brain, increased risk of injury, dehydration, and loss of lean body mass.

ETA; Note that the few studies where they found said negligible differences are still being looked over by the rest of the scientific community and may well be disputed anyway.

For cardio anyway, nearly all of my personal bests (time or distance) have come from running fasted. When I'm lifting, its quite the opposite. However I can't eat at all within the 2-3 hours before a workout - I get horrific side stitches if I do. So I need to lift fed, but on a closer to empty stomach.

I can't workout (cardio nor strength) on a full stomach, else it will come right back up. Yet fasted workouts make me ill and faint. So I do have to have something in me. My happy place is a meal of something like oats, fruit and yogurt (carbs and a little protein) an hour or two before workout for energy and optimal performance.

ninerbuff wrote: »

Nope. Because your body still stores glycogen, you'll first use that at fuel. And most people will fade real fast if their glycogen stores get totally depleted.
The main reason I exercise on an empty stomach is when training intense, you don't have to worry about food coming back up.

A.C.E. Certified Personal and Group Fitness Trainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition

Same. Nothing like 160 flip turns to make food come back up. I eat something light about two to three hours before. I wouldn't swim while completely empty.

mwood1234 wrote: »

Is it true to exercise on an empty stomach because then you are burning actual body fat? Whereas, if you eat before working out you are burning the "food" ?

btw-I am still early in my weight loss journey (1-2 weeks).

Only if you burn through the first 200g or so of glycogen, which is stored in your muscles.