It is very important to monitor your client’s heart rate during fitness testing and sometimes during their workout. During a fitness test, you are pushing your client to perform at their highest possible level. In the clinical setting, this may be the first time they have ever physically pushed themselves and it is vital to their safety that their heart rate is monitored at all times before, during, and after the test. In the gym, their heart rate can tell you how conditioned they already are and assist you in knowing where their intensity is or should be while training. Knowing their resting heart rate (RHR) and maximum heart rate (MHR) is good, but knowing how to find their heart rate reserve (HHR) and target heart rate (THR) will greatly improve the quality and safety of their workout.
A person’s resting heart rate will give you a decent idea of where they are at physically. Normal resting heart rate is between 60 to 100 beats per minute. A lower resting heart rate is thought to show a higher fitness level and stronger cardiovascular system if there are no under lying medical conditions such as bradycardia. An elite athlete could have a resting heart rate as low as 40 beats per minute and be in optimal health. If the resting heart rate is over 100 beats per minute, this is considered as tachycardia, then the person is at a lower cardiovascular conditioned level. This is very important to know before testing or working out because resting heart rate will give a base line to use for monitoring and to gauge recovery time.
Maximum heart rate is defined as the highest heart rate an individual can achieve under stress (testing or working out) without causing severe harm to their cardiovascular system. Knowing this will assist fitness professionals figure out where their clients target heart rate range should be for various goals whether is to lose weight, improve aerobic conditioning, or build their anaerobic threshold. The most common way to find an individual’s max heart rate is 220 – age. I am 25, so this means that my max heart rate is around 195 (220-25=195). Keep in mind that while this is a highly-used means for determining a max heart rate, it may not always be correct due to some individuals being highly trained, or highly sedentary, but it is a very good estimate none the less.
Heart rate reserve is the difference between the resting heart rate (RHR) and the max heart rate (MHR). This is used to find an individual’s target heart rate for different modalities of training. According to the American College of Sports Medicine (ACSM) moderate intensity is classified as 40% - 60% of you heart rate reserve and vigorous intensity is greater than 60% HHR. Using myself as an example again, My MHR is 195 and my current resting heart rate is 60 beats per minute. Using the equation 195 – 60 = 135 (MHR-RHR=HRR), my heart rate reserve is 135. After finding my HRR, I can now begin to find my target heart rate zones by using the percentages and add them back to my RHR. For moderate activity, I want my heart rate to be between 40% and 60%, so I will use the equation: 135 x 0.4 = 54 (HRR x 40%) and add the 54 back to my RHR of 60 to find my lower range of moderate activity of 114 beats per minute. Using the same equation, I will now find 60% of my HHR (HRR x 60%) which is 81. Adding that to my RHR gives me 141. This means that my target heart rate range for moderate activity is 114-141 beats per minute. To find my THR range for vigorous exercise will be between 60% and 100% of my HHR, which gives me a range of 141-195 beats per minute. These can be broken down even further for exercise implications. The “fat burning zone” is widely known as being 60% - 70% of HRR, 141-155 for me. 70% -80% is considered the aerobic training zone (using oxygen freely, such as running or swimming) which would be 155-168 in my case. And the range for anaerobic activity (not getting an adequate oxygen supply, such as resistance training) is 80% - 90% HRR, again in my case 168-182.
Heart rate monitors are great tools for fitness testing and every day workouts, but the tool is only good as the person wielding it. These equations are very simple to use and not only make a huge impact on any training regimen, whether in the gym or hospital setting, but also helps to keep professionals informed on how well their client is doing from a safety stand point.
ACSM Certified Fitness Professional