What Distance To Sprint To Burn Fat

Sprinters have long been admired for their lean, muscular physiques. High-intensity sprinting is one of the most effective ways to burn fat in a short time. When including sprint training in your fat loss program, include both short- and long-distance sprints, ranging from 50 m to 400 m, to promote optimal fat loss.

Anaerobic and Aerobic Exercise

Sprinting is an anaerobic exercise. Anaerobic exercises are activities that are short in duration, typically less than two minutes, and do not require oxygen to fuel the activity. The primary fuel source in anaerobic activities comes from carbohydrates or glycogen stores in your muscles. Fat is not the primary source of energy, because oxygen is required to break down fat to be used for fuel. Essentially, while you are sprinting, a larger percentage of the total calories you burn come from carbohydrate stores, not fat stores. The higher the intensity of the sprint, the larger the percentage of calories that comes from carbohydrate stores. However, when you reduce rest periods between sprints, your aerobic endurance becomes stressed. As a result, your body begins to convert fat stores into fuel.

Intensity and Sprint Distance

In sprinting, intensity is influenced by distance, speed and rest periods between sprints. The faster you run, the more intense the activity and the more calories you will burn per minute. However, extreme high-intensity activities can be sustained only for a short period owing to factors such as lactic acid accumulation in the muscles. Short-distance sprints -- under 200 m or less than 30 seconds in duration -- can be performed at top speed because they are short in both distance and duration. Longer-distance sprints -- 300 m or 400 m sprints lasting 30 to 60 seconds -- are also high-intensity, but cannot be performed at the same maximum speed as short-duration sprints. Last, the rest periods between sprints affect intensity. The shorter the rest period, the less time your body has to recover from the activity, and the higher the intensity.

Post-Workout Fat Loss

Sprinting also promotes fat loss by keeping your metabolism elevated for several hours after your workout to aid in muscle recovery. The higher the intensity of the activity, the longer your metabolism will stay elevated. Because sprinting is a high-intensity exercise, your metabolism remains elevated for longer after your workout than after moderate-intensity aerobic exercise. A greater percentage of calories burned in a sprint workout will come from fat stores.

Sprinting Workouts

Beginners should start with short-distance sprints once or twice a week on nonconsecutive days. After consistently performing short-distance sprints weekly, add an extra day of sprints, up to three a week, or replace a short-distance sprint workout with a long-distance sprint workout. A sample short-distance workout might be eight 100 m sprints at 80 percent of maximal speed. A sample long-distance workout might be one 400 m sprint, two 300 m sprints and three 200 m sprints. Rest periods between all sprints should be the time it takes to walk back to the starting point. Always begin each sprint workout with a thorough warmup. For example, jog 400 m followed by four or five 50 m sprints at 50 percent to 70 percent of maximal speed.