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Exercise Intensity...What Should it Be?

© Mindy Herzog

Exercise intensity is how hard you are working. Intensity and duration of exercise determine the total caloric expenditure during a training session. So, when you are ready to take that step from being physically active to exercising for specific cardiovascular endurance purposes, you’ll need to know about intensity.

The American College of Sports Medicine (ACSM) recommends an intensity corresponding to between 40-50% to 85% Heart Rate Reserve. Determining your target heart rate based on heart rate reserve is a popular method because it has you in mindy. It uses your age and your resting heart rate to determine your target heart rate. The more fit you are, the more comfortable you will be working at a higher intensity.

Target Heart Rate

First you must determine your range: 50-60% Beginning Exerciser – exercising <1 month for a minimum of 2 days a week 60-70 % Intermediate Exerciser – exercising > 2 months for a minimum of 3 days a week 65-85% Advanced Exerciser – exercising > 2 months for most days of the week

Now for the calculation: Take and record your resting heart rate. This is best done early in the morning before getting out of bed. If that isn’t convenient, you can rest in a seated position for 5 minutes and then measure it.

Find your radial pulse on the thumb side of your wrist or use the carotid artery on the side of the neck. Count the number of beats for 60 seconds. This will be used as your resting heart rate (RHR).

Take 220-AGE = maximum heart rate (MHR)

MHR—RHR = Heart Rate Reserve (HRR)

Take HRR X intensity (.50—.85) and + RHR to this number. This will be your target heart rate range.

Example: Age 20, RHR 70 bpm 220—Age (20) = 200 MHR 200—RHR (70) = 130 HRR

Intensity chosen = 50-60% 130 X .50 = 65 + 70 (RHR) = 135 bpm 130 X .60 = 78 + 70 (RHR) = 148 bpm

The target heart rate range for the example would be 135-148 bpm. This would be the range the individual would want to be between when training aerobically.

So after your easy warm-up you will move into the endurance phase of your cardiovascular workout. You will want to take a heart rate count around the midpoint of your activity. For convenience, you can take a pulse count for ten seconds to see if you’re in your range. So, for the intensity above, a ten second count would be 22-25 bpm. (Just divide by 6 to get a 10 second rate.)