|ISSN No. 1606-7754 Vol.17 No.1 April 2009|
Effects of progressive resistance training and aerobic exercise on type 2 diabetics in Indian population
Shweta Shenoy, Ekta Arora, Sandhu Jaspal
Department of Sports Medicine and Physiotherapy, Guru Nanak Dev University, Amritsar, Punjab, India
Background and objective: The Indian population faces a high risk for diabetes because of a high genetic predisposition and susceptibility to environmental insults. The objective of this study was to evaluate the effects of 16 weeks of Progressive resistance training (PRT) and Aerobic exercise (AE) on glycemic control, blood pressure, heart rate, muscle strength and control of type 2 diabetics. Materials and Methods: A total of 30 type 2 diabetics, 14 females and 16 males, aged between 40-70 years, were randomly assigned to the 16 weeks supervised PRT (n=10), or AE (n=10) or Control group (n=10). Pre- and post-outcome measures included glycosylated hemoglobin (HbA1c), fasting blood glucose (FBG), blood pressure (BP), heart rate (HR) and isometric muscle strength of the right hamstring and quadriceps muscles. Results: Plasma glycosylated hemoglobin levels decreased significantly (p=0.002) both in the PRT (7.57 ± 1.4 to 5.74 ± 0.8) and in AE group (8.11 ± 0.9 to 6.78 ± 1.3). FBG decreased by 39.9% in PRT group by14.3% in AE group and by 18.6% in the control group. PRT group exhibited significant reductions in blood pressure (p=0.002 for systolic BP, p<0.001 for diastolic BP) and heart rate (p=0.007). Improvements in isometric muscle strength and balance were seen in both exercise groups. Conclusion: PRT is a more effective form of exercise training than AE for improving glycemic control, blood pressure and heart rate in type 2 diabetics.
Keywords: Aerobic exercise, Progressive resistance training , Muscle strength, Glycosylated hemoglobin, Type 2 diabetes
The number of diabetics is rapidly rising all over the globe at an alarming rate and it is estimated that India will have 79.4 million diabetics by the year 20301. An important factor contributing to the increasing number of type 2 diabetics in Asian Indians is high insulin resistance compared to Europeans which could be due to an environmental or genetic factor or a combination of both2. Endoplasmic reticulum (ER) stress could result in beta cell dysfunction and insulin resistance. The concept that ‘the sustained ER stress of obesity, or chronic over-nutrition in the absence of obesity, can get transduced into increased insulin resistance’ is significantly important for Indians as they experience total epidemiological diet transition.3 Also type 2 diabetes is associated with changes in the diet patterns and decreased physical activity.4 The burgeoning epidemic of type 2 diabetes mellitus is of grave concern because of its human and fiscal costs and the morbidity and mortality associated with the disease.
Traditionally, aerobic activities have been recommended for people with type 2 diabetes because of the known benefits on insulin sensitivity and glucose tolerance. It is estimated that only 28% of individual’s with type 2 diabetes achieve these recommendations.5 Type 2 diabetics have an increased number of type II b muscle fibers, a low percentage of type I fibers and a low capillary density. This abnormal muscle fiber composition may also affect tolerance for aerobic capacity.6 Recently, the American College of Sports Medicine (ACSM) has recommended the use of progressive resistance training (PRT) as part of well rounded exercise program for individual with diabetes.6 Resistance training improves insulin sensitivity and glycemic control.7,8.
A review of literature suggests that in India the focus of research still remains at the level of the detection of diabetes, studies of complications and epidemiological data.3,4 Recently, a study was done by Misra A et al on Asian Indians with type 2 diabetes to determine the effects of progressive resistance exercise(PRE),9 but this study had some lacunae, such as the absence of a control group to compare with PRE, age group of patients was 25-50 years and no standardized PRE guidelines were followed. Randomized controlled trials to study the effects of modification of lifestyle factors including diet, physical activity and obesity have not been reported in the literature. Considering this fact, the primary aim of our study was to determine whether resistance training and aerobic exercises improve glycemic control and other outcome measures in the quality of life of type 2 diabetics. A secondary aim was to consider the economic implications and identify areas of future research.