Exercise Intensity refers to the amount of energy spent while exercising. The expended or spent energy varies from person to person and is dependent on the BMR (basal metabolic rate) of the body. Intensity of exercise has effects on the fuel consumption and the post workout adaptations of the body.

Intensity can also be termed as the amount of physical power that is used by the body when performing an intense act. For example, exercise intensity can define how much effort the body has to put if one has to walk half a mile in ten minutes.

Choose your training zone by THR

Fitness experts say that Aerobic exercises should be “moderately to challenging” intense. The obvious question now is how to determine the intensity of exercise. There are three main ways in which to do this. Target Heart Rate, Talk test and rate of perceived exertion. Target heart Rate is the commonest and easiest method of measuring intensity. Subtract your age from 220 (226 if you are female) to get your Mhr (Maximum Heart Rate).

Alternatively you can apply the Karmoven formula or a treadmill stress test. If your age is above 35 years and you have lived a sedentary life, its best to have your optimum training zone clinically tested. If you plan to start intense exercise as a beginner, its best to wear a heart rate monitor.

There are different kinds of training zones. Healthy zone or warm up zone which allows you to exert to 50-60% of your Mhr. This zone is beneficial for the cure of obesity, high blood pressure and cholesterol.

Fitness training zone extends up to 70% of Mhr and has the same benefits as its previous zone but burns a lot more calories.

Endurance training zone employs up to 80% of Mhr and is generally meant for endurance training.

The next zone is Anaerobic training which uses up to 90% of Mhr, 15% of total calories burnt comprise of fat cells. This training zone strengthens the body’s lactose tolerance level and strengthens the cardiovascular system.

The last level is Red Line (over 90% of Mhr) which requires you to be in excellent physical shape before you start training. You can only stay in this zone for short periods with medical approval.

RPE and Talk Test

RPE or rate of perceived exertion is the most versatile method of measuring exercise as it can be done across all age groups and requires no calculations. In this method, you have to feel how hard you are exerting yourself during exercise and fix your scale according to it.

The scale runs as follows;1-rest, 2-very light,3-light,4-fairly light,5-somewhat hard,6-almost hard, 7-hard,8-extremely hard,9-very hard,10-extreme exertion. The recommended range for adults is 5-7 RPE. People who have taken beta blocker medicines, diabetics and pregnant women can only use RPE for measuring intensity. Talk test is another method of measuring exercise intensity. The talk test says that you should work out at a level which allows you to talk comfortably.

For example, you are exercising too hard if your words come out in sharp gasps. On the other hand, if you are singing comfortably without breathing hard while exercising, you are probably not working out hard enough.

Fuel used and BMR

Fuel used by the body during exercise is generally of two types, carbohydrates and fats. Carbs are burned more in high intensity activities short burst activities and fats are burned more in low intensity long duration activities. This happens because in low intensity exercises the body does not have to produce energy/ATP (adenosine triphosphate) immediately. So the kind of food you have will have a direct bearing on the intensity of exercise you can sustain.

This explains why athletes are advised to be on a high carb diet, specially before an event. Research has proved that periods of intense activity interspersed by relatively sedentary periods can lead to a small but significant change in BMR (basal metabolic rate). Basal metabolic rate is the calorific measure of food you need to consume in order to maintain your current weight.

The ideal BMR level in a normal healthy Caucasian is supposed to be around 74.4%.This means that 74.4% of your body mass is burning energy while you rest. As you start working out regularly your BMR level rises, increasing your muscle mass and your body’s capacity to burn calories.

Recent scientific research shows that Cr (Creatinine) supplements improve the body’s stamina for strenuous athletic performance like jumps and sprints. So if you want to stay fit and get the maximum benefit out of your exercise regime, you must plan your exercise intensity.