A Answers (5)
Michael Roizen, MD, Internal Medicine, answeredIt will maximize fat burning in your muscles, but not all over your body. When your body doesn’t have a ready energy store, it turns to the fat and sugars in your muscles. When that’s used up, the next thing to go is your muscle, which is not good. However, if the early morning is the time you have allotted to exercise, and love to exercise, get up a little earlier, make sure you drink two glasses of water, and have a light meal that contains both carbs and protein. Liquids, like a fresh fruit smoothie with non-fat yogurt, will be less likely to cause cramps during your work out. But any exercise is better than none and I like exercising before breakfast.
You will burn a higher percentage of fat by exercising on an empty stomach, but only if using a low intensity exercise (walking, light cardio). However, by exercising at a low intensity you will not burn many calories, which is ultimately what causes weight loss.
As exercise intensity increases (running, weight training) you use more and more carbohydrates as a fuel source. If exercising at a higher intensity your body will turn to proteins (muscle) as a fuel source if you are running low on carbohydrates, which will happen if exercising for an extended period on an empty stomach.
First off, it's important to note that at least 8 to12 hours may pass between dinner or an evening snack until waking. This means energy levels are at their lowest upon waking or after a long break between meals. Secondly, exercise itself does not burn a great amount of fat no matter how long the activity. It is the contribution of exercise to a person’s total daily energy expenditure (TDEE), including the intensity, that affects fat loss. In other words, exercise simply adds to your daily calorie burn, and as long as you don’t consume more to compensate (keeping your intake below your burn) the body must draw on its fat stores and you’ll lose fat throughout the entire day. So if you properly eat before exercise, you have the potential to perform better, enhance recovery and burn more calories, including fat calories. The higher the intensity of your workout (which you can now perform thanks to having filled your energy stores with a pre-workout snack), the more calories from fat you will use throughout the day. The energy or calorie deficit, not the workout or when you eat, determines how much weight/fat you lose. We’re not suggesting you add calories to your daily intake. Simply adjust the way you distribute your total allowed calories (based on your goal) throughout the day. Spacing meals properly has added benefits, such as using more calories to digest each meal, a steady stream of nutrition (enhancing recovery and energy) as well as controlling hunger.
In general, the short answer is no because an empty stomach means lower intensity, and lower intensity does not maximize your fat burning potential. You perform less work and can’t work as hard simply because you don’t have enough fuel in the tank. Lower intensity workouts not only burn fewer calories during the workout but after it as well, a double whammy to your calorie burning efforts.
This particular myth often turns up the microscope on a short 20-60 minute period of time, the duration of your cardio session. Fat burning is about how much fat your burn versus how much you consume over a 24 hour period of time, that is, the big picture. Remember, exercise is controlled stress placed on the body; the body should be well prepared to take that stress on. And part of that is being properly fueled. Your results will be better and so will your recovery.
Fuel your training and fuel your progress!
National Academy of Sports Medicine answeredNo. This theory runs counter to human physiology. The premise that this works on is that in the morning with an empty stomach you will have low muscle glycogen (energy) stores. As a result, when you do your cardio, the body will have little choice but to use fat for fuel. This plan fails to realize a couple of important things. First, fat only burns in a carbohydrate flame. There must be glycogen available to help the fat burn, and if not, exercise performance will be severely limited or stopped altogether (think "bonking" or hitting the wall). Second, total calorie intake versus burn will determine whether you lose fat or gain it not what fuel is used at a specific period of time.Helpful? 1 person found this helpful.