burning fat or glucose

IncredibleHulk

I have read that for first 20 min of exercise we burn glucose instead of fat What does that mean exactly? Is it the difference between aerobic and anaerobic exercise? If continue after 20 min will it burn fat?

Pugsley

At the start of any workout you burn your muscles energy (glucose) stores before your body starts to use fat stores as fuel.

ali.c

IncredibleHulk wrote:

I have read that for first 20 min of exercise we burn glucose instead of fat What does that mean exactly? Is it the difference between aerobic and anaerobic exercise? If continue after 20 min will it burn fat?

Anaerobic means literally without oxgen* so if you are performing anaerobic excercise your body combusts the fuel (glycogen) in your muscles without oxgen, this type of excercises is high intensity and is performed for short intervals (like sprinting for example) in contrast aerobic means in the present of oxgen*, and is performed at lower intensities than anaerobic excercises.

Depleting the glycogen stores isnt a bad thing though, as it is replished when you eat == less carbs to be stored as fat

*spelt wrong to avoid censoring......

2Scoops

As stated above, the initial period in an exercise session will burn carbs instead of fat. Ditto if you increase the intensity halfway through a session. The relevance? Almost none whatsoever.

Expending energy, regardless of substrate, will ultimately lead to fat loss as long as you're not eating too much. Fat will be used to replace glycogen used during exercise (at least in part) and training will eventually lead to more efficient use of fat during the exercise itself.

In general, light/moderate intensity exercise after ~30min will result in more fat utilization during exercise but it will still be a carb/fat mix. The problem is that at these lower intensities calories burned/min is less than high intenstity exercise. However, high intenstity exercise can't be maintained for as long. But does result in higher post-exercise energy requirements.

rubadub

I was reading that book "burn the fat feed the muscle", it was talking of morning training before breakfast.

Does anybody know how long it takes for the food to take effect? i.e. if I gulp down museli and cycle for 30mins right away do I still, in effect, have an empty stomach?

i.e. it is going to take a while for the food to be digested, so my muscles should still be depleted of glycogen.

crotalus667

rubadub wrote:

I was reading that book "burn the fat feed the muscle", it was talking of morning training before breakfast.

Does anybody know how long it takes for the food to take effect? i.e. if I gulp down museli and cycle for 30mins right away do I still, in effect, have an empty stomach?

i.e. it is going to take a while for the food to be digested, so my muscles should still be depleted of glycogen.

Pro bodybuilders do their cardio before breakfast, im sure if they could of found a way around it they would of found it by now :rolleyes: , Is the question that you are really asking “can I scoff my breakfast then cycle like feck to work and call that cardio on an empty stomach ?” to answer that no once you swallow you no longer have an empty stomach Im not sure how long it takes for the food to kick in my guess would be anywhere between 10-30 minutes , but if your doing intense cardio I doubt it will stay down , Id be inclined to bring a shake with me and down it after the cycle , hope this helps , by they how would you rate the book ???

ps
the pros seem to do about 40-45 mins I’ve done cardio on an empty stomach (first thing in the morning) before and gotten a good hour out of it (then went on to another not so good hour) as far as I know 3 hours without food is considered an empty stomach (although I stand to be corrected)

rubadub

crotalus667 wrote:

Is the question that you are really asking “can I scoff my breakfast then cycle like feck to work and call that cardio on an empty stomach ?” to answer that no once you swallow you no longer have an empty stomach

That is the question pretty much, obviously the stomach is not empty but the real goal is doing cardio with no glycogen in the muscles so you burn fat reserves instead.

crotalus667 wrote:

Im not sure how long it takes for the food to kick in my guess would be anywhere between 10-30 minutes

I would have thought so too. Most say eat 30-60mins before a workout so your body has all the energy ready to go.

crotalus667 wrote:

Id be inclined to bring a shake with me and down it after the cycle ,

I have done that a few times, bring breakfast into work, will probably continue to do this. I am thinking of changing my route to work so I can get 50-60mins cycling done in the morning.

crotalus667 wrote:

how would you rate the book ???

The book is very good, nothing really new (so far) if you have read the links in the stickies, it is in nice simple language, debunks myths and explains how normal diets fail etc. I have only read a few chapters so far. A bit "american" but not as bad as I thought it would be. Lots of sensible advice and maths showing calorie usage.

IncredibleHulk

rubadub wrote:

I was reading that book "burn the fat feed the muscle", it was talking of morning training before breakfast.

Does anybody know how long it takes for the food to take effect? i.e. if I gulp down museli and cycle for 30mins right away do I still, in effect, have an empty stomach?

i.e. it is going to take a while for the food to be digested, so my muscles should still be depleted of glycogen.

Thanks for the replies. I read that by cycling /exercising before breakfast one would burn fat rather than breakfast? I plan to cycle cos cannot walk far due to medical reasons. Better to cycle before or after breakfast?

crotalus667

IncredibleHulk wrote:

Better to cycle before or after breakfast?

IMO before

rubadub

IncredibleHulk wrote:

Better to cycle before or after breakfast?

Yes before. Best to know why though. After sleeping your muscles are low in glycogen which give them/you energy. Now if you cycle your body starts using its fat reserves as fuel (since there is no glycogen). If you ate breakfast your muscles would start to fill with glycogen again and your breakfast would fuel you.

There are other reasons too, raises the metabolism afterwards and insulin levels are low which are meant to help burn fat.

By coincidence today is the first time I properly went without breakfast and took and extra long route to work to get in 45mins of cycling.

Arrived in sweating like a mad man! had an apple and oat flakes and feel great. It wakes you up a lot. Cycling to work is on of the best things I ever took up, I much prefer exercising with a reason, I also cannot skip a "workout" if I am not in the mood.

IncredibleHulk

rubadub wrote:

Yes before. Best to know why though. After sleeping your muscles are low in glycogen which give them/you energy. Now if you cycle your body starts using its fat reserves as fuel (since there is no glycogen). If you ate breakfast your muscles would start to fill with glycogen again and your breakfast would fuel you.

There are other reasons too, raises the metabolism afterwards and insulin levels are low which are meant to help burn fat.

By coincidence today is the first time I properly went without breakfast and took and extra long route to work to get in 45mins of cycling.

Arrived in sweating like a mad man! had an apple and oat flakes and feel great. It wakes you up a lot. Cycling to work is on of the best things I ever took up, I much prefer exercising with a reason, I also cannot skip a "workout" if I am not in the mood.

Thanks very much for the why, I appreciate it. My cycling is not very fast on an old bike, all I can do