Exercising on an empty stomach, good or bad idea?

Raise your hand if you have ever tried to exercise on an empty stomach. If you have, well, you're not alone! There is a misconception that if exercising without "fuel" you'll burn more fat and calories. Turns out that this is actually probably not the best decision. According to the fitness experts at sparkpeople.com, if you do this, then "your body does not have enough adequate fuel to workout at it's optimum level." Here's some more information about exercising on an empty stomach from Spark People's Exercise Tip of the Day...

Question: I heard that when you exercise on an empty stomach (such as first thing in the morning) you'll burn more fat. Is this true?

Expert Answer:
In the morning, your body has gone 8+ hours since eating or drinking anything. Your blood sugar levels are lower at this point, and your body doesn't have adequate fuel to workout optimally. Usually, experts recommend eating something--even if it's just a small snack--within 2 hours before working out. When your body doesn't have proper fuel in it, many problems can result, the lesser being that your workout performance suffers, and the greater being something like passing out during exercise.

However, every body is different. Some people can workout on an empty stomach with no problems, while others would end up very sick and feel the negative effects of it. When I workout in the morning, I always eat (and drink) something first thing after I wake up. Usually by the time I start my workout it doesn't hurt my stomach to exercise with a bit of food on it.

Also, I think there might have been a bit of confusion here about metabolic rates in the morning. Eating breakfast in the morning has a positive effect on your metabolism, but exercising on an empty stomach does not. Some people say that it will burn fat stores, but overall, the number of calories your burn during a workout (regardless of where they come from) is much more important. Plus, fat burns in the carbohydrate flame. This means that exercising without eating (such as after "fasting" during sleep) your body does not burn fat efficiently, or sometimes at all.

Of course you should always check with your physician before starting any kind of exercise/workout routine, and try to eat something, like a banana, before hitting the gym or going for a cold, morning jog.