It not only increases athleticism by building fast twitch muscle fiber, it is highly effective for fat burning.
Performing sprints a few times a week can replace long cardiovascular workouts on treadmills or ellipticals.
The key to getting the most out of your sprinting sessions is to perform them at 100 percent intensity.
The numbers don’t lie
When the body performs any explosive movement at a high intensity it releases growth hormone in the days to follow, to aid in recovery. One study showed that a 30 second all-out sprint increased HGH 530 percent over baseline levels. High growth hormone levels are ideal for keeping body fat low and building lean muscle.
Sprinting increases size of the mitochondria, the part of the cell which stores energy. This makes the body more efficient at releasing energy and thus it has less propensity to store body fat for energy. This means that sprinting not only oxidizes fat, it also prevents the body from storing new fat.
When compared to low intensity exercise, sprinting and other high intensity training burns far more fat and calories. A 20-minute workout session doing high-intensity sprints is roughly comparable to an hour-long cardio workout at a lower intensity.
Start with caution
When starting out with sprints you need to be very cautious because the body needs time to adjust to this type of intensity. To avoid injuring yourself, start out by stretching and doing a little jogging and then work up to moderate intensity sprints. After completing moderate intensity sprints for your first few sessions you can start doing full intensity sprints.
The only thing more effective than sprints
To get the very most out of your sprinting sessions find a hill to sprint up. The only thing more effective for fat loss than sprinting is sprinting uphill. Many professional athletes use this technique to reach peak physical form.
If you looking to get your body-fat percentage down into the single digits, sprinting is the answer. Combined with the proper diet you can achieve the very lean and sculpted look so many strive for. Sprinting in general is far more effective and efficient for burning calories, increasing athletic performance and burning fat than low intensity exercise. Not only that, but you can enjoy much shorter workout sessions!
The next thing we need to discuss is proper running mechanics. This is where most people get it all wrong.
Since this is not a discussion on maximal speed training or mastering the 40 yard or 100 meter dash we won’t concern ourselves with the start so much.
Instead, to be safe, we will use flying starts, meaning you start by running at less than your maximal speed and work your way up to top speed over the course of 15-20 yards.
• Starting from the top down, the face must be relaxed. Do night clench your jaw or make any crazy faces. Relax.
• Keep the chest up and shoulders back and down.
• No side to side rotation of the pelvis, torso, shoulder girdle is allowed.
• Hips remain forward toward the finish line at all times.
• Arms should be bent ninety degrees with the hands open (no clenched fists or flailing, limp wrists).
• When you are running the arms must pump vigorously, forward and backward. NEVER LET THE ARMS CROSS THE MIDLINE OF THE BODY. Only forward and backward. Little kids run with their arms side to side.
• Think of pulling yourself through the air by driving your arms back as fast and hard as you can. The hands come up to a level even with the face and they come down and cross your pocket on the way back (but no further; don’t have them swinging way behind you).
• Drive the knees high and be sure that the foot strikes directly under your body; not out in front of you (although, on a hill this may be slightly different depending on the incline).
• Only the front portion of the foot should strike the ground; the heel should never make contact.
• When the ball of the foot makes contact with the ground think of yourself as an animal pawing at the ground and rapidly pulling it behind you.
• As Charlie Francis said, running takes place on the ground, sprinting takes place above it. If you do it right you should feel minimal impact or stress and should feel like you are flying effortlessly. If you’re taking a lot of pounding and it feels like a lot of work, you’re doing something wrong and should consider having someone watch or video tape you for some feedback.
What I listed above are basically the instructions for flat ground sprints but can easily be applied to the hill.