Fasting during exercise

[NTB]

Here's an article summarizing several recent studies showing that fat loss is accelerated by working out on an empty stomach:

http://news.yahoo.com/s/ap/20100603/ap_on_he_me/eu_med_exercise_while_hungry

The basic point is that if you are low on stored carbohydrate (glycogen) and your insulin levels are low, your body's only option is to burn fat.  And it does so rapidly!
This is a fairly balanced article, giving due space to skeptics and pointing out the possible downsides of such an approach. There are caveats here about moderation and not overdoing the fasting bit.  And others argue that the best approach is to do some workouts fasted, but others after light eating.  My personal experience is that fasted workouts are great, and I've really reduced bodyfat while increasing my strength and lean body mass. 

One point I'd add to this article is the caveat that people should be patient and allow time for their metabolism to gradually adapt to fat burning during exercise.  The first few times, you may actually experience increased hunger, but this is a temporary effect that goes away after a while. Along these lines, since I measure my blood sugar experimentally, I noticed that when I first started out with fasted workouts, my blood sugar dropped after exercise. However, after a few weeks, especially after intense exercise, my blood sugar levels were significantly elevated, and my appetite was totally suppressed. (After easy walks, my blood sugar still stays level or goes down slightly). So obviously, some adaptation was going on. I think this is the effect of adrenaline release mobilizing fat and glucose out of storage. I would be interested if others have found the same thing. This aspect is not explored in the article.

This study is very consistent with a lot of other research on fasted workouts.  One of the best sites on the benefits of fasted workouts is Martin Berkhan's Leangains blog: (http://leangains.com/).  If you want to see an example of a muscular guy with very low body fat, check out pictures of Martin.  I would never want to look that muscular and lean, but at least it makes the point.  Another good site on this is rusty Moore's Fitness Blackbook (http://fitnessblackbook.com/), which aims toward a more reasonable degree of lean muscularity, again advocating fasted workouts.

[nicoledc109]

Here's an article summarizing several recent studies showing that fat loss is accelerated by working out on an empty stomach:

http://news.yahoo.com/s/ap/20100603/ap_on_he_me/eu_med_exercise_while_hungry

The basic point is that if you are low on stored carbohydrate (glycogen) and your insulin levels are low, your body's only option is to burn fat.  And it does so rapidly!
This is a fairly balanced article, giving due space to skeptics and pointing out the possible downsides of such an approach. There are caveats here about moderation and not overdoing the fasting bit.  And others argue that the best approach is to do some workouts fasted, but others after light eating.  My personal experience is that fasted workouts are great, and I've really reduced bodyfat while increasing my strength and lean body mass. 

One point I'd add to this article is the caveat that people should be patient and allow time for their metabolism to gradually adapt to fat burning during exercise.  The first few times, you may actually experience increased hunger, but this is a temporary effect that goes away after a while. Along these lines, since I measure my blood sugar experimentally, I noticed that when I first started out with fasted workouts, my blood sugar dropped after exercise. However, after a few weeks, especially after intense exercise, my blood sugar levels were significantly elevated, and my appetite was totally suppressed. (After easy walks, my blood sugar still stays level or goes down slightly). So obviously, some adaptation was going on. I think this is the effect of adrenaline release mobilizing fat and glucose out of storage. I would be interested if others have found the same thing. This aspect is not explored in the article.

This study is very consistent with a lot of other research on fasted workouts.  One of the best sites on the benefits of fasted workouts is Martin Berkhan's Leangains blog: (http://leangains.com/).  If you want to see an example of a muscular guy with very low body fat, check out pictures of Martin.  I would never want to look that muscular and lean, but at least it makes the point.  Another good site on this is rusty Moore's Fitness Blackbook (http://fitnessblackbook.com/), which aims toward a more reasonable degree of lean muscularity, again advocating fasted workouts.

Thanks for sharing.