Let's say you've been trying to get rid of fat for years, but to no avail, and now I'll tell you why. When fully understood, it will help you to stop doing something that is impossible to succeed at, and that keeps hitting you.
Most physicians, dietitians and government agencies still say that weight management is simple, as long as you burn more calories than you eat. Their views on weight management are as biased as those of the geographer, the continental drift, or the creationist view of earth science. What they call "eating less and moving more" completely ignores the effects of insulin. Any discussion of how many calories to eat, as opposed to how many calories to burn, must include the role of insulin, which determines whether sugar or fat is metabolized, and a condition called homeostasis.
Homeostasis is when your body stabilizes inputs and outputs to keep you alive, and you don't have to worry about it: your body quivers to keep warm, or you sweat to keep cool. If shivering is not enough to warm your body, you will wear a coat for comfort; And when it's hot outside, you take off clothes. When your body needs your help to maintain comfort, homeostasis calls you into action.
When it comes to eating and exercising, homeostasis goes beyond willpower and determination. Consider this: a pound of fat has 3,500 calories, whether it comes from a salmon, a pig, a pile of soybeans, or your belly fat. An hour of strenuous exercise can burn 700 to 900 calories, depending on your size and endurance. Let's count 700 calories, because that's the metabolic rate most people can afford if they're forced to jog for an hour.
Mathematically, to burn a pound of fat, at 700 calories per hour, you would have to exercise for five hours and not eat any more calories. The problem is, exercise makes you hungry, and when you're metabolizing glucose, you can't exercise for more than two or three hours without getting more glucose. For every 700 calories of carbs consumed, you would have to work out an extra hour to eliminate 3,500 calories from that pound of fat. This extra hour of exercise turns into an hour of activity that increases appetite.
If you make it through five to seven hours of jogging and burn 3,500 calories, you'll be ravenous for the next few hours and will eat all the calories back up, because homeostasis insists on keeping your output in balance with your inputs. Willpower has nothing to do with it. Your body is "bound" to recover lost calories.
So if you're jogging just to burn calories, there's a scientific reason to stop. Exercise strengthens muscles and maintains blood flow, calms you down, gets rid of body waste, and even increases endorphins. There are many benefits, but none of them include weight loss. Enjoy hiking, walking, rowing, cycling and swimming, regardless of how many calories are metabolized.