I weigh 61kg (some (too much) of which is fat). If you expend more calories than you take in, you will lose weight.

So how come I am supposed to re-fuel mid ride? Why can’t I just keep on riding until I have burnt off the fat? Why do you bonk?

When you eat gels or bars or energy drinks on a ride, do they go to fat then energy? Does some go to glycogen and some to fat?

If you ate a mega high calorie meal, how long does it take for your body to turn your food into fat?

Thanks.

Basically it’s because the muscles use predominantly carbohydrate rather than fat when working hard in an activity like cycling. Our bodies can only store so much carbohydrate as glycogen in the muscles and the liver I think.

Roughly enough for about 2 hours of active cycling depending on the level at which you are riding. After that the body will start to burn more fat but your energy levels will be severely depleted and you will hit the wall or ‘bonk’ as cyclists traditionally describe it.

There are many resources on line that can explain it a lot more fully than I can but basically depending on the level of cycling that you are doing you should look to replace about 50-60g of carbohydrate per hour of activity. This should also be high glycemic index sources of carbohydrate which get absorbed by the gut relatively quickly for use by the muscles.

I can’t answer the rest of your queries about food turning to fat I’m afraid but as I said before there are mega amounts of resources on line which should be able to answer your queries if you Google for them.

as i understand it you bonk/need to refuel to maintain glycogen stored in your muscles. This is easily available energy which is effiecient to use.

Turning fat to energy is a very costly and ineffiecient process which can only be performed fast enough to support very low intensity excersize (ie ‘fat burning zone’ of heart rate monitors)

Depends how hard you exercise. If you ride 100% aerobic then you have enough spare oxygen to burn fat and can ride for a very long time. If you start using Anaerobic bursts, you’ll be using muscle glycogen, which is a finite stored resource, but can be replenished by fat burning / calorie consumption. So you can bomb completely, back off and recover by riding easy enough that your body can burn fat to restore glycogen stores.

If burning maximum calories is the aim, you would do best by riding really hard (using mainly glycogen stores) rather than riding aerobic as you will burn more calories in recovery to restore the glycogen than you would burn for the same duration of aerobic exercise.

If you ate a mega high calorie meal, how long does it take for your body to turn your food into fat?

Your body can’t turn non fats into fat, all it will do is store some of the excess fat in your diet which isn’t needed. So if you eat a diet high in fat & sugar, sugar gets used first to restore glycogen and then the fat gets stored (as its excess calories). If you ate just fat (and not too much) that would get burnt and used to restore glycogen and no excess fat would be stored.

Your body can’t turn non fats into fat, all it will do is store some of the excess fat in your diet which isn’t needed. So if you eat a diet high in fat & sugar, sugar gets used first to restore glycogen and then the fat gets stored (as its excess calories). If you ate just fat (and not too much) that would get burnt and used to restore glycogen and no excess fat would be stored.

I’m afraid that’s just not right at all. Did you not see the recent series on BBC “The Men Who Made Us Fat”?

Fructose in our normal sedentary diets is now thought to be a bigger problem than saturated fat. That’s not including the fructose naturally found in fruit by the way. Watch this YouTube video for the complete lowdown.