What are the methods to assess exercise intensity?

Answer 1

There are a number of methods to assess exercise intensity. Some of these methods include taking your heart rate, timing the speed on the exercise, and using your own body's gauge to determine the intensity.

Answer 2

One method is to monitor the heart rate of the individual undertaking the exercise. There are suggested ranges of heart rate for people of differing ages and for differing intensities of exercise. The method for estimating these is outlined below.

Another simple guideline for estimating exercise intensity is based on heart recovery rate once exercising has finished and states that 5 minutes after exercise has finished, your heart rate should have fallen below 120 beats per minute. If it has not, then the exercise has been too intense for your current level of aerobic fitness and it is suggested that you reduce the intensity until your fitness improves.

Broadly there are two zones of heart rates:

1. The fat burning zone

2. The cardio zone

The exact bounds of these zones varies from person to person, but an estimate can be made based on age.

In this example it is assumed that the person is a 25 year old with a resting heart rate (RHR) of 60 beats per minute (BPM).

To estimate your maximum heart rate (MHR), use the following equation:

MHR = 217 - (0.85 x age) = 196 BPM.

To find your resting heart rate, it can be measured directly. This would normally be done first thing in a morning when you wake up (before getting out of bed and before drinking anything containing caffeine).

In order to find the range of heart rates corresponding with the exercise zones, it is necessary to find your heart rate reserve (HRR):

HRR = maximum heart rate - resting heart rate.

In our example:

HRR = 196 - 60 = 136 BPM

In general the "fat burning" or low intensity zone is equal to approximately 60-70 % of your heart rate reserve plus your resting heart rate.

RHR + (0.6 x HRR) <= Fat burning zone >= RHR + (0.7 x HRR)

In our example:

60 + (0.6 x 136) = 142 BPM

60 + (0.7 x 136) = 155 BPM

This means that if your heart rate is in the range 142 to 155 BPM, your exercise intensity is in the fat burning zone (assuming you are 25 and have a resting heart rate of 60 BPM).

In general the "cardio" zone is equal to approximately 70-80 % of your heart rate reserve plus your resting heart rate.

RHR + (0.7 x HRR) <= cardio zone >= RHR + (0.8 x HRR)

In our example:

60 + (0.7 x 136) = 155 BPM

60 + (0.8 x 136) = 169 BPM

This means that if your heart rate is in the range 155 to 169 BPM, your exercise intensity is in the cardio zone (assuming you are 25 and have a resting heart rate of 60 BPM).

If your heart rate is higher than this then you are working outside the most effective cardio exercise zone.

When the heart rate of the individual is in the fat burning zone (more correctly it is this zone that trains your body to be more efficient at metabolising fat as a source of fuel) the majority of energy expanded during the exercise is used burning fat (as the name suggests).

This exercise tends to be of lower intensity (e.g. a fast / brisk walk or slow jog).

The cardio or aerobic exercise zone improves the bodies cardio-vascular system, making the transfer of blood around the body and oxygen and waste gasses to and from the lungs more efficient. This tends to occur during higher intensity exercise where the heart rate is higher (e.g. during moderate to fast jogging).

In this region the majority of calories burned during exercise are carbohydrates. However it is suggested that exercise at this intensity can boost the metabolic rate for a period upto 24 hours after the exercise has finished and as such you will be burning more calories than normal even after the exercise has finished.

Answer 3

Intensity is measured in weight training by using a percentage on your one rep maximum.