Reference Guide to Aerobic Exercise

The American College of Sports Medicine (ACSM) defines aerobic exercise as "any activity that uses large muscle groups, can be maintained continuously, and is rhythmic in nature." It is also defined as exercise that increases the need for oxygen. Aerobic exercise is used interchangeably with the terms: cardiovascular exercise, cardio-respiratory exercise and cardio. Some examples of aerobic exercise include: walking, jogging, running, dancing, rollerblading, bicycling, swimming, aerobics classes (both land and water), rowing, stair climbing, et cetera.

Aerobic exercise strengthens your heart and lungs (which make up the cardiovascular system). During exercise, your muscles demand more oxygen-rich blood and give off more carbon dioxide and other waste products. As a result, your heart has to beat faster to keep up. When you follow a consistent aerobic exercise plan, your heart grows stronger so it can meet the muscles' demands without as much effort. Everyone, regardless of their weight, age, or gender, can benefit from aerobic exercise.

Regular aerobic exercise, performed most days of the week, also helps reduce the risk of illness and premature death. Regular aerobic exercise improves health in the following ways:
  • Reduces body fat and improves weight control
  • Reduces resting blood pressure (systolic and diastolic)
  • Increases HDL (good) cholesterol
  • Decreases total cholesterol
  • Improves glucose tolerance and reduces insulin resistance
  • Decreases clinical symptoms of anxiety, tension and depression
  • Increases maximal oxygen consumption (VO2 max)
  • Improves heart and lung function
  • Increases blood supply to the muscles and
  • Enhances your muscles’ ability to use oxygen
  • Lowers resting heart rate
  • Increased threshold for muscle fatigue (lactic acid accumulation)

How Much Aerobic Exercise Should You Do?

When considering the guidelines for aerobic exercise, keep the FITT principles in mind (Frequency, Intensity, Time and Type).
  • Frequency: Number of aerobic exercise sessions per week
    Aim for a minimum of three days per week with no more than two days off between sessions. Gradually work your way up to five or six days per week. Frequency is especially important when it comes to weight loss since more cardio sessions will help you burn more calories. Give yourself at least one to two days off from aerobic exercise each week.
  • Intensity: How hard you should exercise during each session
    Aerobic exercise should take place at a "moderate" intensity level (not too easy, not too hard). This intensity is ideal for the general health benefits that come with exercise, and for weight loss. Exercise intensity is most often measured using heart rate. The recommended heart rate range is 60 85 percent of your maximum heart rate. This range is called the target heart rate (THR) zone.
  • Time: How long each exercise session should last
    Aim for a minimum of 20 minutes per session. Gradually work up to about 60 minutes over time. The further you go over 20 minutes, the more calories you’ll burn and the more endurance you will build. Of course, you might not start an exercise program with a lot of endurance, but you'll slowly build up. Time can be cumulative. You don't have to do 60 minutes all at once. You can do several 10-minute mini-workouts each day and add them up for pretty much the same benefits.
  • Type: What counts as aerobic exercise?
    Any activity can count as cardio/aerobic exercise as long as it meets the three requirements above (frequency of three to five days a week, moderate intensity, and lasts at least 20 minutes per session). It’s important to not confuse "activity" with "exercise." Not everything you do that’s activity is the same thing. Bowling, fishing, playing darts, and similar "activities" aren’t necessarily cardio just because you’re up and moving.

Get the Most Out of Your Aerobic Workouts

  • Check with your doctor before starting an exercise program.
  • Choose an activity you enjoy. You are more likely to stick with it.
  • Always warm-up for at least five to 10 minutes before starting your activity.
  • Start slowly and listen to your body. Go at a pace that feels good to you.
  • Always cool down at least five to 10 minutes at the end of your activity.
  • Vary your exercise program to avoid boredom and plateaus. Changing your routine every six to eight weeks is crucial to keeping your body/muscles surprised and constantly adapting. They'll have to work harder, you'll be challenged, and you'll burn more calories and build more lean muscle in the process. 
  • Instead of trying to exercise through an injury, give it time to heal.
  • Reduce exercise intensity in response to very hot or humid environments or to altitudes above 5,000 feet.
  • Drink plenty of water before, during and after exercise to stay hydrated.
  • Avoid strenuous aerobic exercise during viral infections such as the flu or upper-respiratory tract infections.
  • Stop your exercise session and contact a doctor if you experience chest discomfort, lightheadedness or dizziness.

Training Methods

There are various types of training methods, depending on personal preference. Use each of the methods periodically to add variety to your workouts.
  • Continuous training is the most common method of aerobic exercise. It involves sustaining one exercise intensity for several minutes 20 to 60 minutes (or more for long-distance training) at a time.
  • Interval training involves alternating between higher and lower intensity intervals throughout one workout. 
  • Circuit training uses a series of exercise stations (which could also include strength training stations), with relatively brief rest intervals between each station. The purpose is to keep the heart rate elevated near the aerobic level for a variety of exercises. 
  • Cross-training basically means participating in a variety of different forms of aerobic exercise, either within each session (for example, biking for 15 minutes and then running for 15 minutes) or day-to-day (for example, running two days a week, cycling two days a week, and swimming one day a week). It’s a good idea to cross-train to prevent plateaus and overuse injuries and boost your overall fitness level.