Understanding Exercise Intensity and Target Heart Rate

In April Active Living Fitness Club had "Member Appreciation Month" to celebrate one year of being in business. In the celebration of our first anniversary, we decided to "give back" to our members and clients by organizing different contests, prizes and guest speakers to come in and talk about various fitness related topics.

As the presenter of the Exercise Intensity and Target Heart Rate talk, I thought I'd share a brief outline of the topic to hopefully allow others to gain a better understanding of what level of intensity to exercise at, in order to see improvements in health. As a certified personal trainer through the Canadian Society for Exercise Physiology since 2009, and a recognized, level 1 Exercise Is Medicine professional, I've become quite familiar with this topic and its importance in the fitness industry.

So here's the scoop on exercise intensity:

If you are taking time out of your day to exercise its important to make it worth your while. Ask yourself this question: When you are working out are you working out hard? Or hardly working? Exercising at the correct intensity can help you get the most out of your physical activity by making sure you are not over doing it or undergoing it.

Exercise intensity is quite simply, how hard the body is working during physical activity. What helps determine the ideal intensity level depends on your health, fitness goals and current level of fitness. We describe exercise intensity as "light", "moderate" and "vigorous".

Health initiatives such as Exercise Is Medicine Canada and The World Health Organization have set physical activity guidelines to encourage people to get the right amount of physical activity needed to see improvements in health. So as adults, we are encouraged to obtain 150 minutes of moderate to vigorous physical intensity per week, and include at least 2 days of full body strength training per week.

So what exactly is moderate and vigorous physical intensity?

Light effort is described as 35-55% of your maximum heart rate (220-age). Using the "Talk Test" you should be able to easily talk while exercising at this intensity level and you should start to feel warm while exercising. Examples of light effort activity would be cleaning the house or doing some light gardening.

Moderate effort is described as 55-70% of your maximum heart rate. Using the talk test, you should only be able to give short sentences while exercising at this intensity level and you should start to feel very warm while exercising. Examples of moderate effort activity would be brisk walking, water aerobics or casual cycling.

Hard or Vigorous effort is described as 70-90% of your maximum heart rate. Using the talk test you should only be able to speak 1-2 words at a time and you should start to feel hot and starting to sweat while exercising at this intensity level. Examples of hard or vigorous effort activity would be running, jumping rope, or hiking up a hill with a heavy backpack.

Ways of Measuring Exercise Intensity

Without getting too complicated with mathematical equations, there are simple ways to help us figure out what target heart rate zone we should be exercising in. The best way we can measure exercise intensity is by using a heart rate monitor! Popular gadgets like the FitBit and AppleWatch have heart rate monitors built right in so it is becoming easier than ever to track heart rate during exercise. Most cardio machines have heart rate hand sensors to give an estimate of working heart rate, but these can sometimes be misleading and not very accurate. The talk test, and perceived exertion scale are other good ways of monitoring intensity level that go based on how you feel and do not require any equipment at all.

Ways of Adding Intensity to Your Training

Strength training: Try taking minimal breaks between exercises and sets. Add full body, explosive movements into your circuit training to get your heart rate up.

Cardio Training: Try interval training! For example, if you like to walk on the treadmill, try increasing the incline up high to walk up hill for 2 minutes, than bring the incline back down to allow yourself to recover. You can repeat this as many times as it takes to tire yourself out!

Try something new! Fitness classes and having a personal trainer can help you challenge your body further than what you would normally do on your own. A personal trainer can calculate all your target heart rate zones to make sure you are working at the correct level of intensity for your specific goals.

Progression

Another important point about exercise intensity is the Law of Progression. According to the Canadian Society for Exercise Physiology, the law of progression states: "As an individuals capacity improves, they will be able to do more work and the initial program may not be sufficient to stimulate continued physiological adaptation." (CSEP pg. 128) Based in this principle, the initial workload must increase to see continued improvements in fitness. There are three main ways of progressing a workout program, you can use Frequency, (perhaps exercising 3 days per week instead of 2) Duration, (extending the length of time your workout takes) and of course adding Intensity. For anyone new to exercise, focusing on frequency and duration as forms of progression are better ways of encouraging steady progression rather than adding intensity right away. Light or very light intensity effort that replaces sedentary behaviour can also reduce the risk of chronic disease and still provide further health benefits.

Think About Your Goals!

Exercise should reflect what you want to achieve. For example, if your goal is weight loss, losing weight is about reaching a calorie deficit. You need to burn more calories through exercise than you take in with food. In doing so, your body needs to be working at a moderate to vigorous effort to be able to see your desired results. Whatever your fitness goals, its crucial to start slow. Over exercising can lead to burn out and put you at an increased risk of injury. If you're new to exercise starting slow is the best way to learn to enjoy exercise and slowly make it part of your weekly routine. Fitness is a journey, not a destination so make sure you choose a workout routine you enjoy!