explain to me...this glycogen

[Deleted User]

well, i was thinking about this.

when you have a rumbling tummy, does that mean you have no glycogen left?

or does it mean that your body is reluctantly switching to glycogen from glucose as a source of fuel and is voicing it's protest?

or does it mean that you are starting to burn fat as the main energy source because all the glycogen and glucose are used up.

similarly, how do you know when your glycogen stores are full? apart from a blood test, is there any sensation???

[Deleted User]

BP - I think the main reason for your stomach rumbling is that the food from your last meal has passed through into the intestines. This leaves your stomach empty, which is detected by the brain. This in turn leads to hunger pangs which are designed to be felt well before your body reaches minimal glycogen levels; your body prefers regularity rather than extremes. Sometimes it's also your body's way of saying it's thirsty before you actually feel thirsty. Try having a drink one day when you're 'hungry' and see how long it is till your next pangs, assuming it is less than 2-4hrs since your last meal, not all day, in which case it's definitely food you want!!

The body can exercise at about 70% intensity for around 60mins using glycogen, after which time, stores are greatly depleated. The body then uses a combination of blood glucose and glycogen. After 2-3hrs, the body runs out of glycogen and runs entirely on blood glucose and fat stores. In short, daily life is is not intensive enough to bring about the same effects as in prolonged exercise. We utilise energy slowly enough to either replace it or gradually switch to fat and protein for energy. This is less noticeable than hitting the wall in a marathon, though can often lead to nausia, etc. if you go all day without eating.

I don't really think there's a definnite point when you know your glycogen stores are full - well, my body never tells me! - but if you're ever worried you may be depleated before a run, aim to consume 1g carbohydrate per kg of your body weight about 1hr before your run. This should see you through, though you'll need to experiment. In general, consume around 5-7g carbs/kg, and 8-10g/kg if you're carbo loading. Remember to drink extra water to store all the carbs though, and that these figures are based on averages not YOU, so be willing to fiddle.

Hope this helps a bit to start with at least.

[Deleted User]

thanks for taking the time for the reply freakette,. but i'm not really experiencing a rumbling tummy of anything, and not having trouble witht he carbo loading, i was really just curious!!!

but thanks for the reply.