Losing weight simply means burning more calories than you eat. The sums seem simple, but reality isn’t always easy, especially when it comes to our efficient bodies.
The number of calories we burn varies according to our size, weight, gender, fitness, and muscle mass, so it can be very tricky to calculate exactly how many calories a person is using up during exercise. Calorie counts on fitness trackers and gym machines don’t take these individual differences into account. They’re all based on averages and are notoriously inaccurate so should be taken with a pinch of salt. Experienced distance runners, for example, typically burn 5–7 percent fewer calories than novice runners for the same distance and pace, because novice runners have yet to develop a smooth, efficient technique.You may have heard that low-medium intensity exercise, such as jogging or brisk walking, is the best way to burn calories because you are working out in your “fat-burning zone” in which your body “chooses” to burn fat because, that way, it doesn’t need to plunder the fast-acting glycogen stores in the muscles. It’s a nice idea, but sadly it’s not true; the proportion of calories burnt off as fat remains roughly the same for most types of exercise.
Things go a little better for fat burning when you exercise at full tilt—then you will be burning more calories overall, so more of those calories will be coming from your fat stores.
Go hard or go home
If you walk two miles in an hour, you’ll burn about 200 calories, with roughly 140 of them fueled by fat. Cycle moderately for that period, and you’ll burn about 500 calories, with about 250 of them from fat. we’re all endurance runners
We are the best long-distance runners on the planet, a fact that has helped us conquer the world. A deer will leave you in the dust if you chased after it, spear in hand, but there is a good chance you could outrun the sprightly hoofed animal in an ultra marathon.
Called persistence hunting, our hunter-gatherer ancestors were able to catch and kill faster and stronger animals simply by chasing them doggedly all day until their quarry collapsed with exhaustion, at which point they would close in to kill their prey. We’ve evolved to be the most efficient traveler of any other land animal. Your hips, shoulders, and limbs are perfectly balanced to swing effortlessly, propelling you forward with barely any effort. This economy of movement uses as little as possible of our stores of precious energy—and is precisely what makes losing weight by exercise alone such a long slog.