Target Heart Rate Zone vs Perceived Exertion Level


Target Heart Rate and Borg’s Perceived Exertion level scale are both a means to gauge exercise intensity. Both methods are equally important in determining whether you are exercising at a level, which will optimally provide improvement in cardiovascular conditioning and keep a safe range. The question here is which method would be most appropriate for you to monitor how much effort you are expending during cardiovascular exercise. Using one or both of these methods is a means to enable you to see improvements in your resting heart rate, and response to exercise.

To start, a definition of each method is necessary to understand as how they are applied according to fitness and health levels:

Target Heart Rate Zone (THR): Range with in which the heart is beating to get the optimum cardiovascular effect. It is recommended that an appropriate range for most healthy individuals to exercise at a level between 55-85 percent of your Maximum Heart Rate. In some cases, your health care provider may decrease persons Heart Rate Zone depending on your health

Borg’s Rate of Perceived Exertion Level (RPE): Developed by Gunner Borg in early 1980’s, the Perceived Exertion is a subjective method based on how hard you feel like your body is working during exercise. Based on a person’s experiences during exercise it gives a correlation between perceived exertion and actual heart rate. RPE is a good estimate of actual heart rate during exercise.

Instructions for determining THR zone: there are two types of determining THR the first is the Karnoven formula and the second it the Simplified Method.

Karnoven Formula:

  • 220-age=maximum Heart Rate
  • Maximum Heart Rate – Resting Heart Rate = Intensity
  • Intensity x .55 (minimum intensity) + Resting Heart Rate = THR zone

This is what it looks like with real numbers plugged into the formula: For instance take a 43-year-old with a resting Heart rate of 60. Below is how the calculations would look like.

  • 220 – 43 = 177
  • 177 – 60 =117
  • 117 x .55 = 64 + 60 = 124
  • 117 x .85 = 99 + 60 = 159

This gives a range of 55%-85% of a THR zone.

Simplified Method:

  • 220 – Age = Maximum Heart Rate
  • MHR x .55 = Minimum THR Zone
  • MHR x 85 = Maximum THR Zone

This is what it would look like with numbers plugged in.

  • 220 – 43 = 177
  • 177 x .55 = 97
  • 177 x .85 = 150

Comparing the Karnoven Formula to the Simplified Method, you can see what an impact that adding in a Resting Heart can make on the training range.

Instructions for determining Rate of Perceived Exertion:
While exercising you will rate how hard, you are working. This is your perception and this feeling should reflect how strenuous the exercise feels to you. This is very helpful in self-monitoring through out an exercise training session. First introduced as a scale of 6-20 it has since been revised to 0-10.

The 20-Point Scale:

6- No exertion at all
8- Extremely light
9- Very light
11- Light
13- Somewhat hard
15- Hard
17- Very hard
19- Extremely Hard
20- Maximal Exertion

Using the 6-20 point scale a rating of 12 would correspond to approximately .55 % of THR zone and 16 to approximately .85% of THR zone.

The revised 10-point scale:

0 – Nothing
0.5 – very, very light
1.0 – very light
2 – Light
3 – Moderate
4- Somewhat hard
5 – Heavy
6 –
7 – Very heavy
8 –
9 –
10 – Very,Very Heavy

The talk test is also a good indicator of measuring exercise intensity. You should be able to carry on a conversation and still breathe comfortably, but not be able to sing. If you can sing the exercise, intensity may be too easy and take it up a notch.

Whichever method(s) you choose, be sure to work within your comfort level. It is not
recommended to exercise above 85% of your maximum heart Rate due to increased risk of both cardiovascular and orthopedic risks. Always check with your health care provider prior to starting an exercise program, they can best help you determine your Heart Rate Range. If working with a Fitness professional they too can assist you in determining your best method of calculating your Target Heart Rate Zone. If you are a beginner to exercise, start out gradual and build up to a level that is tolerable to you. If too strenuous, slow down to reduce the risk of injury. If it does not feel right to you change your level of effort. Exercise according to how you feel and above all else enjoy what you are doing! The results that you so yearn for will transpire before your eyes and improvements to your overall health will be apparent.

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About Author

Cathy Jackson

Cathy has been in the fitness industry since 1985. She has been a nurse (LPN) for several years. She holds certifications as a Master Personal Trainer, Group Fitness Instructor, Pilates Instructor, and Lifestyle Fitness Coach. See my profile page for more information!


  1. Avatar

    The heart rate numbers do not seem right for older fit people. I am 56 so 85% of maximum would be 140. But on the exertion scale, I would rate a heart rate of 140 at 12-13 on the 20 point scale. Working hard (i.e. 15-16 on the scale) produces a heart rate in the 160s. If I am running uphill my heart rate may go up to 180. If I could only work hard enough to reach a heart rate of 140, I would not even bother since the workouts would be so easy they would be a joke.

    • shapefit

      Hi Julie – It sounds like you’re very fit for your age. These numbers are a general range and the recommendations are for older people who have an average level of physical fitness. They will need to be adjusted for individuals who are well-trained.

  2. Avatar

    Is the 220 maximum a scientifically proven limit? I am 37 and my maximum heart rate is 209. I have been there 3 times this year while cycling up a steep hill (going flat out).

    • ShapeFit

      Hi Emmet – This is the standard formula that has been used for a long time based on studies. However, it can be problematic for many reasons. The formula does not take into account several important factors which include: sex, fitness level and overall health. It’s probably best to use it as a general guideline.

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