An interval, according to Webster's, is a space of time between two points or events, or two recurrent conditions. When you relate this definition to sports training, you have an interesting method of building endurance and muscle strength.
Most of you who participate in fitness programs of one kind or another have used the interval training method without even being aware of it.
Continuous, progressive and interval training methods are all useful for enhancing a specific sport. But interval training methods involve more of the anaerobic, or without oxygen, patterns.
Interval training is high intensity exercise periods for up to five minutes at a maximal heart rate of between 80 to 100 percent. This brief period of elevated heart rate is most often anaerobic, followed by intervening rest or relief periods of walking or easy arm low impact moves to keep the pulse elevated at a lower recovery level.
An example would be running full out for your 10- second to five-minute period, then jogging easily within your breathing range for a short interval until you recover your breath, and then repeating the procedure for the length of your workout time. Your intense periods can lengthen as you build your cardiovascular endurance capabilities. Interval training is a type of exercise program that most often simulates the actualities of competition, therefore, building the athlete's confidence and at the same time building endurance.
You can see how you can apply this training method to your daily aerobic workout. Most exercise students will slow and walk for a short breather during the aerobic portion of class. The swimmer will slow side stroke for 30 seconds between heavy lap swimming patterns. The bicycle rider will push hard to anaerobic capacity and then rest the legs and coast for 10 to 20 seconds. Even cross country skiing has its intervals of rest along with the workout.
In an exercise class, the intervals can be adjusted during one running sequence for high kicks, then an easy jog, knee to chest moves and then a two step, etc. This pattern keeps the heart rate up for good endurance training while pushing the cardiovascular system for higher conditioning levels. Its main objective, I feel, is that of stabilizing the working heart rate and also greatly enhancing the recovery rate, the recovery rate being how quickly the heart can recover back to its lower, less stressful, steady endurance condition.
Progressive training methods are used for increasing endurance levels higher and higher for overload or stress on the body's physiological system. This uses the method of higher intensity more often with increases in length of workout time. It differs from interval training in that the exercise gets progressively harder and longer for strength and endurance building. Both interval and progressive training methods apply generally to the athlete who has: First, a goal in mind for competition, time or level of capability, and second, it applies to the exercise student who is not necessarily a beginner. New students in fitness often lack the ability and knowledge to closely monitor themselves, often resulting in stress to the musculoskeletal system.
Continuous training is by far the safest method of endurance training and certainly more appropriate for the beginner or older adult. However, after you have inserted yourself into a sport or exercise program, consider the benefits and fun that interval training affords you. It will relieve your boredom and it can be self applied for those days that you really feel "up," and those days that find your fitness level around your ankles.
Jerry Vance is certified by the American Council on Exercise and teaches fitness at the Carson City Community Center and for the American Lung Association.