How to Measure Exercise Intensity

Target heart rate (HR) is a great way to measure exercise intensity to get the most out of your workout. (Click here to learn how to calculate your target heart rate.) For most people, it provides an accurate way to measure the safety of an activity in relation to the percentage of your maximum heart rate. However, for some people, because of several medications that regulate HR (such beta blockers) or the availability to acquire a device that monitors HR, using HR alone to measure exercise intensity can be challenging.

That’s where rate of perceived exertion (RPE) comes in as a great alternative to measuring HR for individuals wanting to gauge their exercise intensity when measuring HR alone is not an option.

The Borg RPE scale is a subjective scale from 6 to 20 that allows you to identify how much effort certain activities require for you. Using this scale, you can easily self-monitor low-, moderate-, and high-intensity exercise and target how challenging your workout should be. Most exercise, for the average person, should fall into the moderate-intensity category.

• Low-intensity exercise: 9-11
• Moderate-intensity exercise: 12-14
• High-intensity exercise: 15-17

There are three primary ways RPE can be used.

1. Measure progress over time in relation to your fitness level.

Let’s say a particular activity felt like a 14 the first time you attempted it. When repeated several weeks later after regular exercise, the activity may now feel like an 11, thus showing you have gotten stronger and/or increased your endurance over those weeks.

2. Measure the safety of an activity.

For example, when an exercise feels like a 17 and it should feel more like a 13, you know to slow down, decrease weight, or decrease repetitions to prevent injury or illness.

3. Use RPE in combination with target HR to determine and monitor appropriate exercise intensity and safety.

For most people, there is a strong correlation between RPE and target heart rate during exercise. The Borg RPE scale value, if multiplied times 10, should equal your approximate target HR during an activity of that intensity. For example, if you are walking at a moderate intensity with an RPE value of 12, your target heart rate should be approximately 120 beats per minute. Please note: these estimates are designed for individuals who are not taking any HR regulating medications.

So, where should your RPE fall? For most people, the American College of Sports Medicine recommends 150 minutes per week of moderate intensity cardiovascular exercise and 2-3 days per week of strength training at moderate intensity. For both of those types of exercise, RPE values should fall between 12-14 on the Borg scale, but no higher than 16. However, it depends on the activity that you are doing and what is safe for you. If you are newer to exercise or have an illness or chronic diagnosis, it is always recommended to start slowly with your exercise and at lower intensity (lower RPE values) while you build your strength and endurance.

As always, if you are unsure of the safety of your workout routine, check with your therapist, exercise physiologist, or physician for some direction! Sheltering Arms’ exercise physiologists can help you create a customized exercise program specific to your needs. To schedule a consultation, click here or call (804) 764-5275.

References:

AdventHealth Orlanda. (2020) Retrieved from: https://www.adventhealth.com/hospital/adventhealth-orlando/blog/helping-parkinsons-patients-make-most-time-home

American College of Sports Medicine, et al. ACSM’s Guidelines for Exercise Testing and Prescription. Tenth edition. Philadelphia: Wolters Kluwer, 2018.

Centers for Disease Control and Prevention. (2020) Retrieved from: https://www.cdc.gov/physicalactivity/basics/measuring/exertion.htm