Two types of activity you need for a balanced fitness program are aerobic and anaerobic exercise, according to The American Council on Exercise. Aerobic exercise elevates your heart rate, as do some anaerobic exercises. Your heart rate zone, or target heart rate, is a percentage of your maximum heart rate, or MHR. You can estimate your maximum heart rate by subtracting your age from 220 if you are male or 226 if you are female.
Any sustained physical activity that elevates your heart rate and breathing can be aerobic exercise. It must be steady and continuous, but may be done at a comfortable pace. The longer your aerobic exercise lasts, the greater the benefits. Penn State's Recreational Sports Fitness program recommends a duration of at least 12 minutes. Aerobic exercise increases stamina, helps you manage weight and strengthens the heart. Examples of aerobic activities include walking or jogging, swimming and cycling.
If you are just beginning a fitness program, or if you are warming up, your heart rate should be 50 to 60 percent of your MHR. Once you achieve a measure of physical fitness, you should increase your pace until your heart rate is in the 60 to 70 percent of MHR range. At these levels of aerobic exercise intensity, about 85 percent of the calories you burn come from fat and you gain significant cardiovascular benefits.
If you goals include more strenuous activities, such as running a marathon, you’ll need to move your aerobic exercise up to the 70 to 80 percent of MHR range. In this “training zone” you burn more calories, although only 50 percent come from fat. You build your endurance and level of cardiovascular fitness.
Anaerobic means “without oxygen” and refers to the fact that, unlike aerobic activity, it forces your muscles to work in a state of oxygen deprivation. Doing push-ups or weightlifting are examples of anaerobic exercise. However, these exercises don’t raise your heart rate for any length of time. Running or swimming sprints, or a vigorous game of tennis, will raise your heart rate. Anaerobic exercise strengthens your muscles and bones.
For exercises like running sprints, your heart-rate zone to achieve the strength-building benefits of anaerobic exercise is 80 to 90 percent of your MHR. At this level your body burns short term energy reserves and only about 15 percent of your energy comes from fat. Lactic acid builds up in your muscles and you will quickly become winded. Consequently, you can only do anaerobic exercise for short intervals. However, your body will recover in a few minutes, so you can repeat the exercise several times during a single workout.
- The American Council on Exercise: ACE IFT Model for Cardiorespiratory Training: Phases 1–4
- Penn State: Recreational Sports Fitness: Frequently Asked Questions
- The Walking Site: Your Target Heart Rate
- American College of Sports Medicine: ACSM Issues New Recommendations on Quantity and Quality of Exercise