Definition
Anaerobic means “without air" or "without oxygen." Anaerobic exercise is a short lasting, high intensity activity, where the demand for oxygen from the exercise exceeds the oxygen supply. Anaerobic exercise relies on energy sources that are stored in the muscles and, unlike aerobic exercise, is not dependent on oxygen from (breathing) the air.
Examples
Heavy weight-lifting, sprints (running, biking, etc.), jumping rope, hill climbing, intervals, isometrics (in which one part of the body is used to resist the movement of another part) or any rapid burst of hard exercise.
Benefits
Anaerobic exercise uses muscles at high intensity and a high rate of work for a short period of time. Benefits include:
- Development of stronger muscles
- Improved max VO 2 (the highest amount of oxygen one can consume during exercise) and thus an improved cardio respiratory system
- Greater capacity to withstand the buildup of waste substances such as lactic acid and increased ability to remove them from the body. This means your endurance and ability to fight fatigue will improve.
Overall, anaerobic exercise burns fewer calories than does aerobic exercise and may be somewhat less beneficial for cardiovascular fitness. However, it is better at building strength and muscle mass and still benefits the heart and lungs. In the long run, increased muscle mass helps a person become leaner and lose weight, because muscle uses large amounts of calories.
How it Works
As you begin to work out vigorously, there is a temporary shortage of oxygen being delivered to the working muscles. A popular term related to anaerobic energy production is lactic acid. Lactic acid is a by-product of producing energy anaerobically. When lactic acid accumulates at high levels in the blood, it causes muscular fatigue. This is why anaerobic exercises cannot last long. With training, the body becomes better equipped to handle lactic acid. Several efficient changes occur in the body during training that result in decreased production of lactic acid and increased removal of it from the bloodstream.
The body produces “buffers” that delay the onset of fatigue during anaerobic exercise. Studies have shown that with anaerobic training, the muscle’s buffering capacity is increased by 12% to 50%. With this increased buffering capacity, more lactic acid can accumulate during high intensity exercise without causing fatigue.
Cautions
- If you are new to exercise, do not immediately start with high intensity activity. Beginners should start at about 50% intensity and increase from there.
- Anaerobic exercise is not recommended if you are pregnant.
- Do a 5-10 minute warm up before starting any anaerobic exercise, and a 5-10 minute cool down after your workout session.
Training
Interval training is a great anaerobic exercise. It can be done with many types of exercise (for example, running, biking, or swimming). An interval is done by increasing your pace for a short period of time (for example, between 10 to 60 seconds) then having a slow recovery period that is at least 3 times as long as the interval. To interval train, you simply repeat these bursts of exercise during the course of your workout. For example, you can jog for 30 seconds, then walk for 2 minutes, jog for 30 seconds, walk for 2 minutes and so on.
Anaerobic interval training is primarily reserved for those who are very fit and desire to increase speed, lactate threshold, and overall aerobic power. Such training usually results in greater lactic acid concentrations in exercising muscles and is accompanied by greater muscular discomfort. This can be a very intense type of training and should not be attempted by a beginning exerciser. Those who do use this technique should do a considerable low-level aerobic warm up and stretch before and after vigorous activity.
