Interval Training Builds Fitness Fast
Vary Your Training Intensity to Boost Your Performance
By Elizabeth Quinn, About.com Guide
Interval training has been the basis for athletic training routines for years. The first forms of interval training, called “fartlek” involved alternating short, fast bursts of intensive exercise with slow, easy activity. Fartlek was casual, unstructured training that perfectly fit its English translation: “speed play.”
What is Interval Training?
The interval programs of today have become highly sophisticated methods of structured training for athletic performance enhancement. Physiologists and trainers have designed interval programs that are specifically suited to individual athletes. These sessions include precisely measured intervals that match the athlete’s sport, event and current level of conditioning. Often the appropriate intensity and duration of the intervals is determined by the results of anaerobic threshold testing (AT) that includes measuring the blood-lactate of an athlete during intense exercise.
How Interval Training Works
Interval training works both the aerobic and the anaerobic system. During the high intensity effort, the anaerobic system uses the energy stored in the muscles (glycogen) for short bursts of activity. Anaerobic metabolism works without oxygen. The by-product is lactic acid, which is related to the burning sensation felt in the muscles during high intensity efforts. During the high intensity interval, lactic acid builds and the athlete enters oxygen debt. During the recovery phase the heart and lungs work together to “pay back” this oxygen debt and break down the lactic acid. It is in this phase that the aerobic system is in control, using oxygen to convert stored carbohydrates into energy.
The Benefits of Interval Training
This repetitive form of training leads to the adaptation response. The body begins to build new capillaries, and is better able to take in and deliver oxygen to the working muscles. Muscles develop a higher tolerance to the build-up of lactate, and the heart muscle is strengthened. These changes result in improved performance particularly within the cardiovascular system.
Interval training also helps prevent the injuries often associated with repetitive endurance exercise, and they allow you to increase your training intensity without overtraining or burn-out. In this way, adding intervals to your workout routine is a good way to cross train.
According to the American College of Sports Medicine, more calories are burned in short, high intensity exercise. If you are counting calories burned, high intensity exercise such as intervals are better than long, slow endurance exercise, but you may pay a price. Read more about the benefits and dangers of high intensity exercise.
