If you've started sprinting in virtually any capacity, you've already put the right foot forward – no pun intended – to start burning major fat. Vigorous sprints put lower-intensity exercises to shame when it comes to the sheer number of calories burned, but your burn has more to do with your exertion and time spent on the track than it does your total distance. There is no magic distance that will help you burn fat, but distance may play a role in designing your regimen.
Running sprints for about a half hour burns between 300 and 600 calories per hour, according to dietitian Christopher Mohr and athletic supplement producer OneResult. Your total burn depends on factors as diverse as your body weight, the intensity of the sprint and even the incline. At an average sprinting speed of 10 miles per hour, this puts your distance at about five total miles. Unless you're superhuman, however, you won't sprint for five miles at a time – effective, fat-melting sprint workouts typically have their foundation in interval training.
Interval training – more than just a fitness mag buzzword – relies on the simple concept of alternating between short bursts of low intensity and high intensity during your workout. For instance, you might leisurely pedal for 12 seconds on an exercise bike, burst into a sprint for eight seconds and repeat. According to a 2012 study from the “Journal of Obesity,” sprinting in intervals causes your body to release catecholamines. These helpful hormones encourage the release of fat – specifically in the abdominal area, for those working on that flat tummy – from your body's stores, allowing working muscles to burn it off.
Time vs. Distance
Rather than thinking of sprint distance – whether it be a 100-, 200- or 400-meter dash – think in time increments as you design your interval training routine to maximize your fat loss. For instance, doing the 8-second 12-second example on an exercise bike for just 20 minutes three times per week burns just as much fat as jogging for seven hours per week, reports the “Journal of Obesity.” Likewise, the “International Journal of Sport Nutrition and Exercise Metabolism” finds that just two-minute sessions of intense, on-foot sprint intervals are just as effective at burning fat as 30-minute sessions of endurance exercise, such as light running or jogging.
At the end of the day, intensity also trumps distance in the arena of sprinting and burning fat. Exercise, as always, is relative; each woman has her own sprinting speed – if you're running at top speed and intensity, even if you're not as fast as the average Olympian, that's your sprint, and your sprint reaps the same health benefits for you as it does for that Olympian. In addition to melting calories on the track, regular, high-intensity sprint training even raises your resting metabolic rate, meaning you'll burn more fat even when you're not crossing the finish line.
- Mayo Clinic: Counting Calories: Get Back to Weight Loss Basics
- Bodybuilding.com: Burn More Fat by Sprinting
- OneResult: How Many Calories Are You Burning?
- Runner's World: Sprinting for Weight Loss: Are Catecholamines the Secret?
- Journal of Obesity: The Effect of High-Intensity Intermittent Exercise on Body Composition of Overweight Young Males
- Time: Can Two-Minute Sprints Burn as Many Calories as a 30-Minute Workout?
- University of New Hampshire: Sprinting to Your Weight Loss Goal?
- The Sydney Morning Herald: Forget the Jog Slog and Fit in a Sprint for Maximum Weight Loss Results
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