Exercise on an empty stomach

[PaulF]

There was a thread somewhere about the fat burning benefit of moderate exercise on anempty stomach. Does anyone have a link? Or can explain it? I just tried to explain the logic to a colleague and got horribly confused

[Jaded]

Cannot explain it, but I know that if I want to lose weight fast the best way has been to go for a ride before breakfast.

[Chris S]

The general idea is to do a Zone 2/3 (ie - easy to moderate, so a fat burning kind of workload) ride when your glycogen reserves are depleted. The theory being, if there is a shortage of glycogen then your body will be more inclined to use it to burn fat, rather than just use it to power muscles.

I think it works. My variant was to go for a 40km ride in the evening, a couple of hours after dinner, then do another 40km ride the next day before breakfast.

Something changes - because when I started audaxing I needed to eat at least every 50km, but now I can ride 100km straight off, on an empty stomach.

[Blodwyn Pig]

saw the original thread somewhere, and tried it. Initially got all wobbly, but very soon got used to it, now its addictive, usualy do 40 - 50 km most mornings, before breaky, you forget that you havent eaten, and IT WORKS. Combined with eating a bit less, I lost 8kg in 6 weeks!! Dont overdo the fitness bit, sit back, relax, pedal slower, pedal through the wobbly bit ,10mins usually, then gradually speed up!  Enjoy!!!!! Stumpy.

[vorsprung]

Your body needs a certain amount of glycogen to do any sort of exercise.  Glycogen is also used to make your brain work.
When you are exercising at a very moderate level the body can convert fat to glycogen ( or use it directly to some extent ) but this also requires a small amount of glycogen
The easiest way to get Glycogen into the body is with carbohydrates
Glycogen is stored in the body in two main places.  In your muscles and in your liver.
Overnight the supply stored in the liver gets run down

When you wake up in the morning your body is very short on glycogen.  But if you exercise moderately the body will react by tapping it's fat stores.  Normally it won't do this until 30 minutes or so of exercise have happened, it will run off glycogen.  I assume because glycogen is in such short supply the fat is burnt off

Also I assume ( and I could be wrong here, I don't remember reading this ) that the way the fat is burnt is not optimally efficient so more fat is used.
Fat is normally 3,500 calories per pound.  Cycling at an "average" rate is 350 calories per hour, so that's quite a lot of exercise.

Also once you stop exercising and eat, the food isn't converted to fat as normal.  Oh no.  Your body wants glycogen.  As long as you have a reasonable active daily routine after the breakfast won't get made into fat at all.

I think this is pretty much right but I am pretty clueless about physiology so experts please correct...

[mattc]

Our local expert on the subject:

Low carbohydrate diet

(it was all the rage last year, even I gave it a go!)

[inc]

There is some info here www.cyclingnews.com fitness and training information

[mattc]

Sci Am has an article this month about fat burning in sled dogs. Annoyingly they didn't mention any of the research in human endurance sport.

But it confirmed the strategy of burning fat over glycogen to cover 100s of miles (at around 10-12mph!).

(Just the precis:
Scientific American Digital: Digital archive of all issues from 1993 to present. - I read it in my LPL* )

*Local Public Library

[LEE]

Sci Am has an article this month about fat burning in sled dogs. Annoyingly they didn't mention any of the research in human endurance sport.

They said it gives you a husky voice.

[border-rider]

There was a thread somewhere about the fat burning benefit of moderate exercise on anempty stomach. Does anyone have a link? Or can explain it? I just tried to explain the logic to a colleague and got horribly confused

Distance training

rescued from a Previous Place, IIRC.