Effect of Exercise Intensity on Body Composition in Overweight and Obese Individuals

Introduction: Exercise is an important component of weight loss program. The amount and intensity of exercise required to produce a change in body composition and anthropometric measures are yet to be determined. Traditional steady state exercises performed at moderate intensity have been examined for weight and fat loss. Recently, High intensity exercise done for less duration is emerging and gaining importance. We aimed at investigating the intensity of exercise required to produce a significant change in anthropometric and body composition measurements. Materials and methods: Volunteers, sedentary overweight and obese in the age group of 19-35 years, were randomized into group I (n-35) those performing moderate intensity exercise at 50-74% heart rate maximum reserve for 40 min and group II (n=37) high intensity exercise at 75%-84% of heart rate maximum reserve for 20 min on a bicycle ergometer for a duration of 15 weeks. Anthropometric measures and body composition were determined using skin fold caliper. Results: There was a significant change in the weight, waist hip ratio, skin fold thickness, circumference measures, fat mass, fat percentage, and lean body mass among moderate (p<0.000) and high intensity group (p<0.000). A significant change in fat mass (p<0.002) lean body mass (p<0.001) and fat % (p<0.000) in the high intensity group compared to moderate intensity group was observed. Conclusion: It is concluded that 15 weeks of exercise at high intensity is more effective in changing the body composition considering the strategy of time commitment in overweight and obese individuals. Indian J Physiol Pharmacol 2017; 61(1) : 58–64 *Corresponding author : Dr. K. Umamaheswari, Associate Professor, Department of Physiology, ESIC Medical College & PGIMSR, KK Nagar, Chennai – 600 078, Mobile: 9790218060 Email : umamaheswarik89@yahoo.in (Received on April 12, 2016) world and an associated modifiable risk factor for various metabolic disorders. The reason for the increasing trend of obesity in adults is a sedentary life style. It is important to prevent obesity, and exercise is established as an important component of behavioral weight loss program (1). The National program for prevention and control of diabetes and cardiovascular disease suggests moderate to vigorous activity for 5-7 days/week (2). Recognizing exercise protocols that are effective in reducing body fat and feasible to be followed by overweight, sedentary Introduction Obesity is a major health problem of the developing Indian J Physiol Pharmacol 2017; 61(1) Exercise Intensity and Body Composition 59 (BMI≥25) in the age group of 19-35 were included. Exclusion criteria comprised individuals with history of previous surgery, cardiopulmonary and musculoskeletal disorders, diabetics, hypertensives, and asthmatics. Complete clinical examination, ECG and echocardiogram were taken and fitness obtained from physician before volunteers were involved for the exercise program. 91 volunteers enrolled for the study. 72 of them completed the 15 weeks exercise protocol. 12 opted out due to various reasons not related to the study. There was no injury stated due to the exercise. Anthropometr ic measurements: A digital weighing scale that could measure to the nearest 0.1 kg was used to record weight, and height was measured to the nearest centimeter using a stadiometer, in the Frankfurt plane position. Waist circumference was measured in centimeters (cms) midway between the uppermost point on the iliac crest and the lowermost margin of the ribs with the measuring tape parallel to the ground and patient in inspiration. Hip circumference was measured in cms at the maximum circumference of the buttocks at the level of the greater trochanter (7). Waist hip ratio was calculated to be waist circumference in cms divided by hip circumference in cms. Mean of three readings of each measurement was taken for the calculation of WHR. Mid arm, mid-thigh and mid-calf circumference (8) were also measured. Measurement of body composit ion: Skin fold measurements were taken from various sites including biceps, triceps, scapular, abdominal, suprailiac, thigh and medial calf sites according to standard procedures using skin fold caliper. All skinfolds were measured to the nearest 1 mm. Mean of 3 readings was recorded at all the sites. A l l measurements were taken by the same investigator before and after completion of exercise protocol. Durnin’s age specific equations (1974) was adopted to calculate body density that was further used in Siri’s equation (1961) to determine the total body fat. Fat percentage, fat mass, lean body mass (9) were derived using standardized equations. individuals are important. Also an effective exercise training depends on exercise intensity and the duration. Different types of exercise are studied for the purpose of weight loss. Traditional steady state low and moderate intensity exercises done over a period of 45-60 min almost every day in a week have resulted in noteworthy change in body weight thereby reducing cardiovascular and metabolic disease risk. Recently, high intensity intermittent exercise (HIT) that involve repeated brief sprinting at an allout intensity followed immediately by low intensity exercise or rest done for 3-4 days in a week of less duration is gaining importance for the purpose of weight loss and change in body composition. It is also considered as an economical exercise protocol for reducing fat in overweight individuals (3, 4). Studies have examined moderate and high intensity exercise for a change in body composition and have reported conflicting results (5, 6). Limited work have investigated the low volume HIT on people with risk for cardio metabolic disorders and their impending benefits are still uncertain. The optimal amount of exercise necessary to produce a change in body composition is yet to be ascertained and moreover, an exercise program to be operational, must be economical and easy to implement without the necessity of complicated exercise equipment. Therefore, we investigated, a protocol of moderate and high intensity exercise on a simple stationary bicycle ergometer that was required to produce significant change in body composition in overweight and obese individuals.