You probably know aerobic exercise is good for you, at all stages of life. Do you know about the Canadian Physical Activity Guidelines? They recommend adults do at least 150 minutes of moderate- to vigorous-intensity aerobic physical activity per week. Moderate- to vigorous-intensity? What does that mean?
The various intensities you can exercise at can be confusing. I’m going to break it down and answer a question I often get in my job, “how hard should I be working out?”
Tip: If you have a health condition, check with a doctor or an exercise physiologist before increasing your activity levels.
There are three basic physical activity intensity zones:
- Light intensity: A healthy person can be active in this zone for several hours. Those with a health concern, or who are starting out to be active can use this zone to safely enjoy the benefits of physical activity. An example would be going for a walk on flat terrain, light house work, or leisure bike riding (no hills).
- Moderate intensity: This is a pace where you’re working at a steady rhythm but things are still comfortable. For example brisk walking, running at a comfortable pace, or mowing the lawn.
- Vigorous intensity: Things are heating up here! You’ll be breathing more, and most likely sweating. Think like a race or swimming hard. Most healthy adults and older adults benefit from some vigorous intensity in their week. Fun fact, for athletes in competitive settings, the vigorous intensity zone is divided into specific subzones (call us at 8-1-1 if you’d like more information!).
There’s a variety of ways to determine what intensity zone you’re exercising in:
- Rate of Perceived Exertion (RPE): Also called the Borg scale, this is a scale of 6-20 where the numbers correspond to how you are feeling. For example an 8 is very easy exercise where you feel comfortable. While a 19 is extremely hard and you feel very tired, like it’s the hardest exercise you’ve ever done. This scale can be used by all and is very accurate.
- Sensations in your body: Being in tune with your body allows you to determine how hard you’re working. If we look at breathing for example, in light intensity there is barely an increase, while during vigorous intensity breathing is heavy.
- Monitoring your heart rate: Heart rate monitors are fairly common (a chest strap with a watch receiver is the most accurate). They measure how fast your heart is beating; the harder you exercise the faster your heart will beat. There are many formulas to determine heart rate training zones which correspond (to some degree) with the three zones mentioned above. Formulas take into account your age, resting heart rate and if you know your maximum heart rate. Try it out with this neat tool!
- Other ways: Measuring how much oxygen your body uses when exercising at different levels is another way to tell what intensity zone you’re in. This is called measuring your aerobic capacity and is done in a lab. Another way is to use a power meter, found on some spin bikes at the gym. These determine how hard you are working and can help you stay in a specific intensity zone. You can even get a power meter installed on your own bike.
You might have heard that high intensity interval workouts, also called HIIT, are the best way to workout. Or that to achieve a healthy weight you must stay in the so called “fat burning zone” (usually that means moderate intensity). But like eating well, variety is best! Focusing on extremes usually doesn’t turn out well.
Instead of focusing on one specific type of workout or fitness trend, aim to spend at least 150 minutes doing any type of physical activity (more is better) in the moderate-vigorous zone per week and to do light intensity at will.
HealthLinkBC: Exercise and Physical Activity Ideas