How to Tuesdays: Calculating Percentage Based Heart Rate for Optimal Training.

Training using a heart rate monitor will give you a clear view of how your body is dealing with the current exercise load. Whether you are a cyclist, runner or looking to lose some weight you will benefit from this method of monitoring your training. Many people seem to think that keeping their heart rate (HR) high for as long as possible means they have trained hard and well. This is not the point at all. It is all about getting in the zone – you should know what your resting heart rate (RHR) and maximum heart rate (MHR) is and from there work out your zones.

You should take your HR every morning while still in bed to monitor how your body is coping with the previous day’s exercise load. Take an average RHR over 5 days during a rest week to get a reliable base line. If a noticeable elevation in HR is recorded the morning after a hard session you can adjust your training program to ensure that you go into your next work out fully rested. Keep a small diary next to your bed and record each days RHR and your current mood to track your progress. Benefits of training using HR are:

  • Target specific zones to best suit your short term or long term goals.
  • Combat overtraining and undertraining.
  • Predict illness. 

If you already have a HR monitor that is excellent! If not, take a look at how to effortlessly take a HR reading:

Locate your radial artery in your wrist just below your thumb, using your index or middle finger count the beats for 10 seconds and then times that value by 6 to get beats per minute. Depending on your current fitness level your RHR could range from 40-70 BPM.

The Karvonen Formula will then allow you to accurately translate your Maximum Heart Rate (MHR) and RHR into a percentage which allows for individual differences in your current level of fitness.

  Target HR = (MHR-RHR) x % + RHR


 Step 1: Calculate your RHR

Take a reading each morning for 5 consecutive days, preferably during a rest week. This must be done at the same time every morning before you get out of bed. To keep this accurate, put your monitor and diary next to your bed each night before you go to sleep so that you do not move excessively before taking the reading. Add all your readings together and divide by 5 to get an average…right, now that is your RHR. This can be recalculated once a month to allow for progress in your fitness.

Step 2: Calculate your MHR

The MHR test should be activity specific so warm up for 20 min at 8/10 of your maximum effort.

  • Go all out (10/10) for 2 min.
  • Rest for 2min.
  • Go all out (10/10) for 2 min.
  • Keep an eye on your heart rate reading.
  • Cool down for 5 min.

Note: after going “all out” you should not be able to repeat this exercise. You should be completely exhausted. 

  • Now, take the highest value and add 5 BPM and that is your MHR.

Step 3: Finding your target HR zone:

Select a HR zone to train in from the table below:

Target zones

 Step 4: Applying The Karvonen Formula

Say your RHR is 50 BPM and your MHR is 180BPM and your aim is to train in the Aerobic zone at 75%; use the Karvonen formula as follows to determine your heart rate for optimal training:


Target HR = (MHR – RHR) x % + RHR

Target HR = (180-50) x 75% + 50

Target HR 75% = 148 BPM


Your personalized HR to train at 75% is 148 BPM, now you can specifically target your goal of becoming fitter and stronger.

Do you want to develop speed, increase performance, improve your aerobic fitness, manage your weight and endurance or simply improve your health and recover? Let us know how training using your heart rate benefits you?