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DQueens · 03-22-2007, 12:56 PM

hi there,
actually it is a common misconception that excercising before eating anything will help to liberate your fat stores.

I'll try to explain to you how your body works when exercising in an attempt to colour this answer a bit brighter than simply saying "no."

You have two main sources of energy for your cardio exercise in your body: the carbohydrate (glycogen) stores in your muscles and the fat stores, that you most likely want to get rid of. For the first portion of cardio, you will be utilizing both fat and glycogen stores. After about 20-40 minutes, when you have used up a good portion of your glycogen (it varies depending on your level of fitness), you will begin to rely solely on your fat stores to fuel your cardio.

If you havent eaten anything yet, it is most likely that your glycogen stores are significantly lower and therefore you wil have to rely on "fat" to primarily fuel your workout.

However, if you have had a snack a few hours before and substantial meals and, therefore a full stock of glycogen in your muscles, you will burn this first. This seems like your theory is true, right? Well, after your exercise your body will want to replenish your glycogen for your next round of exercise. A good portion of this energy (assuming you are on a reduced calorie diet to lose weight) will come from your fat stores. There has been shown no correlation between how much proportion is energy is used as fat during exercise and how much fat the individual loses overall.

another thing to keep in mind is that when you are quietly sitting and working, sleeping etc. your body (heart primarily) is using mostly fat to fuel itself to keep you alive, and heart pumping.

the main thing you want to do to lose weight with exercise is to create a combined calorie deficit of 500 calories a day (to lose 1 lb a week). You can do this by eating normally and exercising away 500 cals (about an hour run/ hard bike/ elliptical) or you can eat 250 less, exercise away 250 cals or any combo of the two.

hope that helps.

03-22-2007, 12:56 PM	#2 (permalink)
DQueens Member Join Date: Nov 2006 Posts: 65	hi there, actually it is a common misconception that excercising before eating anything will help to liberate your fat stores. I'll try to explain to you how your body works when exercising in an attempt to colour this answer a bit brighter than simply saying "no." You have two main sources of energy for your cardio exercise in your body: the carbohydrate (glycogen) stores in your muscles and the fat stores, that you most likely want to get rid of. For the first portion of cardio, you will be utilizing both fat and glycogen stores. After about 20-40 minutes, when you have used up a good portion of your glycogen (it varies depending on your level of fitness), you will begin to rely solely on your fat stores to fuel your cardio. If you havent eaten anything yet, it is most likely that your glycogen stores are significantly lower and therefore you wil have to rely on "fat" to primarily fuel your workout. However, if you have had a snack a few hours before and substantial meals and, therefore a full stock of glycogen in your muscles, you will burn this first. This seems like your theory is true, right? Well, after your exercise your body will want to replenish your glycogen for your next round of exercise. A good portion of this energy (assuming you are on a reduced calorie diet to lose weight) will come from your fat stores. There has been shown no correlation between how much proportion is energy is used as fat during exercise and how much fat the individual loses overall. another thing to keep in mind is that when you are quietly sitting and working, sleeping etc. your body (heart primarily) is using mostly fat to fuel itself to keep you alive, and heart pumping. the main thing you want to do to lose weight with exercise is to create a combined calorie deficit of 500 calories a day (to lose 1 lb a week). You can do this by eating normally and exercising away 500 cals (about an hour run/ hard bike/ elliptical) or you can eat 250 less, exercise away 250 cals or any combo of the two. hope that helps.