Regularly lifting weights could be a good way for men to reduce their risk of developing type 2 diabetes, according to a new study published Aug. 6 in the journal Archives of Internal Medicine.
The study, the first to link weight training to lowered diabetes risk, followed more than 32,000 men for nearly 20 years, from 1990 to 2008. Every two years, the participants filled out a questionnaire that tracked their exercise — including weight training and aerobic exercise — as well as factors such as smoking, alcohol and coffee intake, and diet. Of the research participants, 2,278 developed new cases of diabetes over the course of the study. That's about 7 percent, below the national average of 11.8 percent for men for both diagnosed and undiagnosed cases of diabetes, according to the National Diabetes Information Clearinghouse (NDIC).
Previous studies have shown that aerobic exercise reduced the risk of developing diabetes, and this study bore that out, but looking at the numbers revealed something new: weight training may have an even greater effect than aerobics. Men who lifted weights between 1 and 59 minutes per week reduced their type 2 diabetes risk by 12 percent. Those who lifted weights between 60 and 149 minutes reduced their risk by 25 percent. Anything more than 150 minutes — roughly 30 minutes a day, five days a week — reduced the risk by 34 percent.
The same amount of aerobic exercise was shown to reduce diabetes risk by 7 percent, 31 percent and 52 percent respectively. Brisk walking, jogging, running, bicycling, swimming, tennis, squash and calisthenics or rowing were all included under the category of aerobic exercise.
Combining both weights and aerobics reduced risk the most. Men who lifted weights for more than 150 minutes a week and had more than 150 minutes of aerobic exercise had the best effect, reducing their risk by 59 percent.
"This study provides clear evidence that weight training has beneficial effects on diabetes risk over and above aerobic exercise, which are likely to be mediated through increased muscle mass and improved insulin sensitivity," senior author Frank Hu, professor of nutrition and epidemiology at Harvard School of Public Health (HPPH), said in a prepared statement. "To achieve the best results for diabetes prevention, resistance training can be incorporated with aerobic exercise."
Lead author Anders Grøntved, a visiting researcher at HSPH and a doctoral student in exercise epidemiology at the University of Southern Denmark, said weight lifting can provide an alternative to men who want to reduce their diabetes risk by have a hard time adhering to a schedule of aerobic exercise. He also said further research is necessary to confirm these results and to see if the results can also be applied to women.
According to the NDIC, about 1.9 million adults over the age of 20 were diagnosed with new cases of diabetes in the U.S. in 2010.
More diabetes stories on MNN: