High-intensity interval exercise

A high-intensity interval exercise prescription is frequently used to get persons to lose weight; it also boosts cardiovascular fitness and improves endurance.

We should be able to exercise for a minimum of 20 to 30 minutes continuously at an intensity of 75 to 85 per cent of our maximum heart rate (without experiencing exhaustion or breathing difficulties) before attempting a high-intensity programme. Thus, it is necessary for us to gradually build our fitness profile before taking on such a physically demanding challenge.

The high-intensity interval prescription should always commence with a warm-up session followed by intervals of high- intensity activities, then medium-intensity activities performed at about a half of our maximum heart rate or rest periods and conclude with a cool down routine. It is necessary to perform the designated number of repetitions and try to keep the activities going for the required time, to enjoy the best results.

Chest pains

This will also help to prevent us from experiencing a plateau in our improvement as we consistently push our body to adapt to new challenges. However, if we develop chest pains or have difficulties breathing during the workout, we should move to the rest or cool down stage immediately. If you think you are taking longer than normal to regain your normal resting status, you will need to reduce the intensity of the activity, as well as increase your recovery period

High-intensity interval activities should target the largest muscle groups in our bodies that can be used comfortably. This will target the best sources of energy in our muscles. Short sprints, cycling on the stationary bicycle, jumping jacks, burpees, power walking ,speed walking are a few of the simple activities we can do in a high-intensity routine. When the activities are performed at the required intensity our bodies will experience increased metabolism via increased oxygen consumption at rest and this reduces body fat and weight.

Session variations

We can use a number of variations to make the high-intensity interval sessions novel. Following the warm up, 20 seconds of very intense exercise could be followed by 10 seconds of rest. This could be repeated continuously for a five-minute session each day, five to six times each week for persons who do not have much time to exercise.

An alternate regimen could be 60 seconds of intense exercise at maximum effort followed by 70 seconds of rest repeated about six to 10 times each day of the week.

High-intensity interval exercises decrease insulin resistance significantly. This helps the skeletal muscle to adapt by improving glucose tolerance and the ability to use fats to produce energy. This is associated with the significant reduction in body fat and muscle retention during weight loss. High-intensity interval exercise is also an important modality in the prevention of type two diabetes and reduces cardiovascular disease risk factors.

Dr Kenneth Gardner is an exercise physiologist at Holiday Hills Research Center; email: yourhealth@gleanerjm.com.