Your body burns fat or carbs depending on the intensity of your activity. You burn fat even if your body is at rest. Actually you are burning fat right now as you are reading. If you are an average person sitting in front of your computer reading this, your body is burning about one or two calories per minute of which about 70 % comes from fat and about 30% comes from carbs.
When you exercise, as the intensity increases, your body starts using more and more carbohydrates for energy instead of fat. At the higher limits of aerobic exercise, 100 percent of the energy is coming from carbs. When carbs are no longer available, the body will break down your muscle and use it for energy. When carbohydrate stores are depleted, the rate at which fat is used as energy is reduced and that’s why carbs are essential in order to metabolize fat.
You lose fat only if you burn more calories than you eat on a daily basis, not because you burn fat or carbs when you are exercising…!
When you eat after your workout you will rapidly replenish the carbs and fats that you have used up during the workout, as soon as an excess of calories exists, your body will begin to store them as fat. This means that your body’s fat stores will be virtually unchanged.
The key to fat loss is to boost your metabolism so that your body is continuously burning calories at a higher rate 24/7. People with muscle mass are automatically burning more calories and fat. Every 5 pounds of muscle that you build on your body will burn up to 15,000 extra calories a month which equals roughly 2 pounds of fat. Building this extra muscle will give you one hell of an advantage and it shows that muscles are the best engine for burning fat.
High Intensity Interval Strength Training using your own bodyweight is the most effective way to burn fat and build lean muscles. A workout should boost your metabolism for as long as 24 to 48 hours after the workout is over. The more intense your workouts are the more fat you will burn and the stronger and leaner you will become. High intensity interval bodyweight training will also improve your cardiovascular strength and endurance, agility, balance, speed, and power.
The reason why you should keep your workout short is because you want to be pushing at your maximum effort. It is simply not possible to sustain this kind of intensity over longer periods of time. Simply put, if you have anything left at the end of your workout, then you didn’t train hard enough. It is really that simple. Everyone has their own level of what max effort means, but the one thing that we should all have in common at the end of a workout is that we should be completely wiped out. You are the only one that controls the intensity of your workout. Everything depends on your effort and how much you are prepared to push in these few minutes of training. If you decide to put comfort before intensity then you are trading away your results.