According to the World Health Organization (WHO), overall, strong evidence demonstrates that compared to less active adult men and women, individuals who are more active:
- have lower rates of all-cause mortality, coronary heart disease, high blood pressure, stroke, type 2 diabetes, metabolic syndrome, colon and breast cancer, and depression;
- are likely to have less risk of a hip or vertebral fracture;
- exhibit a higher level of cardio-respiratory and muscular fitness; and
- are more likely to achieve weight maintenance, have a healthier body mass and composition.
WHO recommended levels of physical activity for adults aged 18 – 64 years
- Adults aged 18–64 should do at least 150 minutes of moderate-intensity aerobic physical activity throughout the week or do at least 75 minutes of vigorous-intensity aerobic physical activity throughout the week or an equivalent combination of moderate- and vigorous-intensity activity.
- Aerobic activity should be performed in bouts of at least 10 minutes duration.
- For additional health benefits, adults should increase their moderate-intensity aerobic physical activity to 300 minutes per week, or engage in 150 minutes of vigorous-intensity aerobic physical activity per week, or an equivalent combination of moderate- and vigorous-intensity activity.
- Muscle-strengthening activities should be done involving major muscle groups on 2 or more days a week.
Exercise intensity refers to how hard your body is working during physical activity. Your heart rate, breathing, temperature and perspiration all measure your level of exercise intensity. Your health and fitness goals, as well as your current level of fitness, will determine your ideal exercise intensity. Target heart rates for fitness and health gains are between 40 and 85 per cent of your maximum heart rate (maxHR).
Typically, exercise intensity is described as low, moderate, or vigorous. For maximum health benefits, the goal is to work hard, but not too hard, described as moderate-intensity by the ‘National Physical Activity Guidelines for Australians’. These guidelines recommend that for good health, you should aim for at least 30 minutes of moderate-intensity physical activity on most days. This is the same for women and men.
Measuring exercise intensity
There are varying ways to measure your exercise intensity to make sure your body is getting the most out of every workout. You may need to experiment to find out which method of measuring exercise intensity suits you best. Three different measurement methods include:
- Target heart rate
- Talk test
- Exertion rating scale.
Target heart rate
The human body has an in-built system to measure your exercise intensity – your heart. Your heart rate will increase in proportion to the intensity of your exercise. You can track and guide your exercise intensity by calculating your Target Heart Rate (THR) range.
For moderate-intensity physical activity, a person’s Target Heart Rate should be 50 to 70% of his or her maximum heart rate. This maximum rate is based on a person’s age. An estimate of a person’s maximum heart rate can be calculated as 220 beats per minute (bpm) minus your age. Because it is an estimate, use it with caution
Keep your heart rate at the lower end of your recommended range if you are just starting regular exercise. Gradually increase the intensity of your workouts as your fitness improves. Also, your heart rate should stay in the lower ranges during warm-up and cool-down periods.
A heart rate monitor is an easy way to keep track of your heart rate while you’re exercising, or you can take your pulse.
If you have a medical condition, are overweight, are aged over 40 years or haven’t exercised in a long time, see your doctor for a medical check-up before starting any new exercise program. Your heart rate target range may need to be professionally recalculated to take your health and general fitness into account.
Some medications can alter your heart rate response to exercise, so make sure you discuss the medications you are taking and how they could affect your exercise plans with your doctor. It may be necessary to use another option for monitoring exercise intensity if you are taking certain medications.