Ever notice the difference between a long distance runner and a sprinter?
Long Distance Runner (left) Sprinter (right)for both pictures.
Notice anything? Perhaps it's hard to tell at first but there are some of the key differences:
1. The sprinter has larger muscles.
2. The sprinter has lower body fat percentage (usually)
3. The long distance runner is more slight in build
4. The long distance runner has much less muscle tone.
If you look up photos of long distance runners vs. sprinters you will notice this trend with most of them.
The way you exercise can determine the shape your body takes. Mainly this is because it determines how your body uses its resources to help you get through these workouts. Long distance runners are doing aerobic exercise, whereas Sprinters and weight trainers are doing anaerobic exercise. The difference is important.
While cardio workouts burn fat and calories over a long period of time, they also tend to burn muscle as well. This is because the body has to find it's largest resource of calories and that tends to be the muscles. Especially after a weight-training workout, one should avoid long distance running, as it negates the process of muscle building. There is nothing wrong with long distance running, in fact it has been proven to promote heart health over sprinting, but if you really want to maintain muscle mass and lose more body fat, sprinting is better choice.
Why does sprinting take off more body fat than long distance running?
Sprinters train with high intensity bursts for short duration periods, burning more sugar, and less fat during the workout. When a high intensity burst of exercise is performed, the body burns more relative amounts of sugar, but burns more fat and calories after the workout. It burns calories anywhere from 16-48 hours after the workout. Low or moderate intensity exercise, such as long distance running, has no after burn effect. You burn what you burn and that is it.
Also important in answering this question is looking at the hormones involved in these two types of exercise. Low to moderate intensity exercise produces a large amount of unopposed cortisol, leading to a catabolic, muscle burning state. High intensity exercise also produces cortisol, but does so along with growth hormone and testosterone, enhancing fat burning, leading to an anabolic, or muscle building state. Therefore the long distance runner has less muscle than the sprinter.
One of the reasons I prefer sprinting is that it takes less time, the workout is harder but not nearly as tedious, and it gets you great results while still maintaining muscle mass. The more muscle mass you have, the higher your metabolism will be. This means that if you can maintain or add muscle to your frame, you will burn more calories than you did before, and lose more weight over time if you continue to take in the same amount of calories you always have. This is why sprinting helps you lose weight more permanently than long distance running. If you had to stop running for a few weeks for some reason, you would still be burning a significant amount of calories by just breathing. However, if you had lost muscle mass, or didn't have much to begin with because you run long distance, you might gain weight over this inactive time, because you aren't burning as many calories.