What Happens When We Burn Fat?

It’s fairly obvious that the dynamic benefits of exercise improve our health and wellness. But what about the science behind this? What causes the beneficial health changes to our body fat and muscle mass?

A pound of muscle, and a pound of fat weigh exactly the same. A pound (duh). However, a pound of fat covers a lot more surface area than a pound of muscle. So, an extra 5lbs of fat is much bigger that and extra 5lbs of muscle, meaning your stomach will appear bigger with the extra fat instead of muscle. Fairly simple yes?

Now, for the more science – y bit…….

Everyone has a certain number of fat cells. These are a set number for us all and wont change much from our youth to an elderly age. They do, however, increase and decrease in size dependant on our nutrition and activity levels. Its all a matter of calorific balance. Fat cells will stay the same size if our calorific intake is the same as our expenditure each day. But if we consume more calories than we utilise each day, then the size of the fat cells will increase, resulting in gaining more body fat. So, if we burn more calories than we consume, fat cell size is reduced, resulting in you burning fat.

But where on earth does the fat go?

Well, this was debated for a long time.

And the answer lies within our respiratory system.

Yes, that’s right. Our breath eliminates most of the fat from our bodies.

Up to 84% of the fat molecules we ‘burn’ are exhaled as carbon dioxide. The other 16% is removed from the body via sweat, urine, tears, and other liquids.  Exercise both increases the amount of calories we burn and our respiration rate, so vigorous exercise is a great way to maximise the fat burn.