Weight training reduces the risks of diabetes

Men who weight train about 30 minutes per day, five days per week may be able to reduce their risk of type 2 diabetes by up to 34 per cent, according to a new study by Harvard School of Public Health and University of Southern Denmark researchers.

And if they combine weight training and aerobic exercise, such as brisk walking or running, they may be able to reduce their risk even further — up to 59 per cent.

This is the first study to examine the role of weight training in the prevention of type 2 diabetes. The results suggest that, because weight training appears to confer significant benefits independent of aerobic exercise, it can be a valuable alternative for people who have difficulty with the latter.

The study is published online in Archives of Internal Medicine this month.

“Until now, previous studies have reported that aerobic exercise is of major importance for type 2 diabetes prevention,” said lead author Anders Grøntved, visiting researcher in the Department of Nutrition at the Harvard School of Public Health and a doctoral student in exercise epidemiology at the University of Southern Denmark. “But many people have difficulty engaging in or adhering to aerobic exercise. These new results suggest that weight training, to a large extent, can serve as an alternative to aerobic exercise for type 2 diabetes prevention.”

An estimated 346 million people worldwide have type 2 diabetes and diabetes-related deaths are expected to double between 2005 and 2030, according to the World Health Organisation. More than 80 per cent of these deaths occur in low- and middle-income countries.

The researchers followed 32,002 men from a Health Professionals Follow-up Study from 1990 to 2008. Information on how much time the men spent each week on weight training and aerobic exercise came from questionnaires they filled out every two years. The researchers adjusted for other types of physical activity, television viewing, alcohol and coffee intake, smoking, ethnicity, family history of diabetes, and a number of dietary factors. During the study period, there were 2,278 new cases of diabetes among the men followed.

The findings showed that even a modest amount of weight training may help reduce type 2 diabetes risk.

The researchers categorised the men according to how much weight training they did per week — between one and 59 minutes, between 60 and 149 minutes, and at least 150 minutes — and found that the training reduced their type 2 diabetes risk by 12 per cent, 25 per cent, and 34 per cent, respectively, compared with no weight training. Aerobic exercise is associated with significant benefits as well, the researchers found—it reduced the risk of type 2 diabetes by 7 per cent, 31 per cent, and 52 per cent, respectively, for the three categories above.