All physical activity burns calories and has effects on the body. However, the intensity of that activity has a significant impact on WHAT and HOW MUCH the body is affected. Over the years, multiple methods have been developed to allow individuals to measure their intensity, even during the activity, so that they are able to exercise in a safe and effective manner. Using methods such as relative intensity, absolute intensity and target heart rate, you can better determine how much your workout is actually working for you.
Per the Centers for Disease Control (CDC), relative intensity is simply “the level of effort required by a person to do an activity.” To determine their level of intensity, an individual should pay attention to their breathing and heart rate. An easy way to measure relative intensity is the “talk test”. If you can talk, but not sing, during an activity, then you are working at a moderate intensity level. On the other hand, if you can’t say more than a few words between breaths, you have moved into the vigorous intensity level.
Another method to subjectively determine intensity level is the Borg Rating of Perceived Exertion (RPE). This method was developed by Dr. Gunnar Borg as a way to estimate heart rate based on the physical sensations a person experiences during physical activity. These sensations include increased heart rate, increased respiration or breathing rate, increased sweating, and muscle fatigue.
Using these criteria, you would match how you feel to a number, ranging from 6-20, on the BORG Scale. A rating of 6 is no feeling of exertion and moderate activities will generally rate 11-14. Vigorous activities are considered 15 or higher. The top of the scale is 20, which is deemed a very, very hard rate of exertion. Multiplying the Borg score by 10 will give an approximate heart rate.
Utilizing this method, you are able to estimate your heart rate and adjust your intensity by speeding up or slowing down movements, even in the absence of a heart monitor or fitness tracker. While an individual’s actual heart rate may vary due to age, physical condition, this can be a useful tool for self-monitoring. Additionally, this method is often used for people who are on medications that can affect heart rate or pulse.
The Harvard Chan School of Public Health, offers this table with examples of activities and how they would likely fall on the Borg Scale.
Rather than rely on how you are feeling, and your perception of how hard your body is working, absolute intensity is a more precise measure of the energy required by the body per minute to continue the activity. To measure this, individuals may utilize some type of heart monitor or other fitness tracker to access their level of exertion.
TARGET HEART RATE
A common fitness tracking term is “target heart rate”. The Mayo Clinic describes this as “the level at which your heart is being exercised and conditioned but not overworked.” To find your target heart rate, first you will need to determine what your maximum heart rate is – or the highest heart rate that your system can handle during physical activity. The simplest way to find this number is to subtract your age from 220. The target heart rate is based off a percentage of the maximum heart rate based on the person’s fitness goal.
According to the American Heart Association, for determining a target heart rate for moderately intense physical activity, individuals should aim for 50-70% of their maximum heart rate. For vigorous exercise, the target heart rate goal is about 70-85% of maximum heart rate.
Generally, if a person is just starting out on a fitness regimen, they will aim for the lower end of their target zone. As their body adjusts to the activity, they could then increase intensity to reach the upper end of their target zone.
While there are many methods of measuring levels of intensity, The Physical Activity Guidelines for Americans, 2nd edition offers the following list of example activities for “moderate” and “vigorous” intensity levels. According to these guidelines:
Moderate-Intensity Activities include –
- Walking briskly (2.5 miles per hour or faster)
- Recreational swimming
- Bicycling slower than 10 miles per hour on level terrain
- Tennis (doubles)
- Active forms of yoga (for example, Vinyasa or power yoga)
- Ballroom or line dancing
- General yard work and home repair work
- Exercise classes like water aerobics
Vigorous-Intensity Activities include –
- Jogging or running
- Swimming laps
- Tennis (singles)
- Vigorous dancing
- Bicycling faster than 10 miles per hour
- Jumping rope
- Heavy yard work (digging or shoveling, with heart rate increases)
- Hiking uphill or with a heavy backpack
- High-intensity interval training (HIIT)
- Exercise classes like vigorous step aerobics or kickboxing
Generally speaking, all physical activity has some health benefit; however, along with these listings, the guidelines note the following U.S. Department of Health and Human Services (HHS) recommendations.
For substantial health benefits, adults should do at least:
- 150 minutes (2 hours and 30 minutes) to 300 minutes (5 hours) a week of moderate-intensity, or
- 75 minutes (1 hour and 15 minutes) to 150 minutes (2 hours and 30 minutes) a week of vigorous-intensity aerobic physical activity, or
- an equivalent combination of moderate- and vigorous-intensity aerobic activity.
Preferably, aerobic activity should be spread throughout the week.
HHS also states that “additional health benefits are gained by engaging in physical activity beyond the equivalent of 300 minutes (5 hours) of moderate-intensity physical activity a week.”
Beyond aerobic exercise, HHS goes on to state that “adults should also do muscle-strengthening activities of moderate or greater intensity and that involve all major muscle groups on 2 or more days a week, as these activities provide additional health benefits.”
Talk to your doctor of chiropractic about your current health status, goals and fitness regimen. Your doctor can help you determine what, if any, changes you may need to make for optimal results. Additionally, your doctor can talk to you about the various methods of tracking your heart rate to help you exercise safely.
If you don’t have a chiropractor, you can find a TCA Member doctor near you at www.tnchiro.com/find-a-doctor/. As you reach milestones and goals, your doctor can help you reevaluate and set new goals, or make changes to your fitness regimen to keep you moving consistently in a healthier direction
Your health is important and your time is valuable. Be sure you are giving your body the best benefit for the work you are doing!
Please note: The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for a diagnosis by a specialist. There are a number of individual factors that may affect your personal maximum heart rate, and thereby your target heart rate zone. Heart conditions and some medications can impact your heart rate. This is why it is important to discuss your personal health status with your health care providers before starting an exercise regimen. For specific information concerning your health condition, consult your chiropractor.
U.S. Department of Health and Human Services. Physical Activity Guidelines for Americans, 2nd edition. Washington, DC: U.S. Department of Health and Human Services; 2018.
The Borg Scale of Perceived Exertion. Harvard Chan School of Public Health. https://www.hsph.harvard.edu/nutritionsource/borg-scale/
Know Your Target Heart Rates for Exercise, Losing Weight and Health. American Heart Association. https://www.heart.org/en/healthy-living/fitness/fitness-basics/target-heart-rates
Exercise intensity: How to measure it. Mayo Clinic Staff. https://www.mayoclinic.org/healthy-lifestyle/fitness/in-depth/exercise-intensity/art-20046887