Running is proven to be one of the most effective ways of losing weight and getting in shape quickly. Prominent weight loss authority Covert Bailey has said that the only thing that removes fat faster than running is a knife. One of the reasons this is true is that running burn a massive amount of calories.

The primary three factors which determine how many calories you burn while running are your weight, your running speed and the distance you run. Most calculations you will see regarding how many calories you have burned while running are based on those three factors alone. However, there are many other factors which affect the number of calories burned: age, sex, the terrain, the weather, your level of fitness, your body fat percentage and many other factors which are difficult to measure. In spite of this, the standard calculation base on those primary factors is a good rule of thumb to follow to help measure the fat burning power of your running program.

The standard formula used to calculate the number of calories you burn with every mile you run is .75 multiplied by the number of pounds you weigh. This makes running a great weight loss activity because the more you weigh, the more calories you burn. For example, if you weigh 170 pounds you will burn 127.5 calories per mile. That formula assumes an easy jogging pace which would cover about 6 miles in an hour. This would mean you would burn 765 calories in an hour long run. For the purposes of comparison, you would barely burn over 200 calories during an hour long walk.

If you run at a faster pace than a slow jog, you will burn even more calories. However, there is a catch to this benefit. The ability to run at a faster pace means that you have gotten more fit. The fitter you become and the less you weigh the fewer calories you burn with the same effort. So over time, as you approach your goal weight, you must eat less or run more to keep losing weight.

To offset this lower calorie burning during exercise, however, your resting metabolic rate will be higher as you get more fit. Your body will burn more calories at rest than it burned when you were fatter.  In addition, as you become fitter your body will produce hormones which make it more effective at burning fat while retaining muscle.

If you find that you have hit a weight loss plateau in your running program, interval training can help spur more weight loss. Interval training is alternating intervals of faster running with intervals of slower running to recover. This is very effective at increasing fat loss, however you have to be very careful to avoid overuse of this method.

There are many ways to incorporate interval training into your running, however the easiest is simply to head to the local high school track and use the standard track distances. Start out with an easy 15 to 30 minute warm up jog. Follow that up with one fast lap around the track. Of course “fast” will mean different things depending upon your level of fitness. Alternate the fast lap with a very slow recovery lap. Repeat this process according to your workout plan. Start with just a couple of fast laps and work up to as many as 20 over time. Don’t jump quickly to twenty. Build up very slowly.

Later on, you can work in longer fast laps. For example, 2 fast laps followed by two slow laps.

Interval workouts cause your body to produce extra growth hormone to help recover. This increased level of growth hormone causes you to burn more calories and build more muscle. Keep in mind that you must be very, very careful to avoid overdoing this type of training. It burns more calories because it is very stressful to your body. If you find that your morning resting heart rate gets higher, or you start feeling tired even when you are not working out, you will need to back off these higher intensity workouts and allow your body to recover.

Added: Craig Payne