How to monitor exercise intensity

Monitoring the intensity of your exercise is essential for ensuring an exercise programme is done safely and effectively and checking that clients are working at an appropriate level.

Monitoring exercise intensity can also provide useful information to determine the success of the session in the short time and provide a benchmark against which future sessions can be progressed and reviewed.

The three key methods of monitoring exercise intensity are The talk test, Rating of perceived exertion and Heart rate monitoring.



When a client is working aerobically and at a moderate intensity an individual should be able to hold a conversation with a mild level of breathlessness at the end of a sentence. The talk test is an easy test to perform and guidelines are simple to follow.

Light activity – Measured by talking easily and breathing lightly, but heart rate has increased.

Moderate activity – Is measured by talking comfortably, but breathing is deeper and quicker, and the body is warming up.

Vigorous activity – is measured by talking more difficultly and breathing deeper and harder. Breathing becomes increasingly difficult as intensity increases to a point where there is a shortness of breath and an inability to carry on a conversation.



RPE provides a scale of how hard an individual feels they are working when they exercise. The response of the client should take into account all the symptoms of exertion, such as breathing, muscular fatigue and the subjective feeling of effort. The original scale ran from 6-20 and is supposed to reflect heart rates ranging from 60-200 bpm. The modified scale runs from 0-10 and offers a more user friendly approach.

It is rated so 0-3 are typically seen as the warm up and cool down zone 4-7 is the aerobic zone and 8-10 is high intensity intervals or anaerobic zone.



Heart rate is traditionally the most common method of monitoring exercise intensity. The main methods for determining heart rate is to manually measure the pulse in the wrist or neck, or to use a heart rate monitor. The latter method is more accurate.

The guidance for improving cardiovascular fitness is that individuals should work at a target heart rate (THR) range between around 50-90% of their maximum heart rate (MHR or HR max) depending on their fitness level.

Maximum heart rate (MHR)

To calculate your MHR you use the equation: 220 beats per minute (BPM) – Age. For example if you were 26 this would be 220 – 26 = 194bpm

Target heart rate (THR)

To calculate your THR and get the upper and lower limits of the target zone you use the following equations: upper – MHR X 0.6 = 60% THR and lower – MHR X 0.9 = 90%

For example for a 26 year old this would be: upper – 194 X 0.6 = 116bpm and lower – 194 X 0.9 = 175bpm.

Heart rate zones

The intensity levels recommended by the American College of Sports Medicine are moderate intensity is 50-60% of your MHR and vigorous intensity is 65-90% of MHR.

In practise a combination of methods may be useful for monitoring the response of a single client or a group of participants.

 If you found this interesting then a career as a PT would be recommended. Please see our list of courses and decide which ones best for you

Stay up to date
with Velocity Academy

Sign up to our Newsletter