Many people worldwide have type 2 diabetes, a metabolic condition in which the body cannot properly regulate blood sugar levels. Experts already know that lack of physical activity can contribute to the risk of diabetes, but what type of exercise might lower it?
Recently, researchers have been looking into the effects of exercise on the risk of type 2 diabetes, asking what kind of physical activity might help decrease it the most.
These researchers hail from Iowa State University in Ames, the University of South Carolina in Columbia, the Pennington Biomedical Research Center in Baton Rouge, LA, and the Ochsner Clinical School at the University of Queensland School of Medicine in Brisbane, Australia.
Their findings — which appeared earlier today in the journal Mayo Clinic Proceedings — indicate that people with moderate muscle strength, maintained and consolidated through resistance exercise, may be at a considerably lower risk of type 2 diabetes.
This effect, the scientists note, is independent of other factors such as cardiorespiratory fitness. They also point out that moderate muscle mass seems to be enough to provide this benefit — increasing it does not lower risk any further.
Associate professor Duck-chul Lee, from Iowa State University, explains that the current findings suggest that even moderate resistance training can be beneficial in this respect. However, he cautions that it is difficult to establish how much is enough.
"Naturally, people will want to know how often to lift weights or how much muscle mass they need, but it's not that simple," notes Lee.
"As researchers, we have several ways to measure muscle strength, such as grip strength or bench press. More work is needed to determine the proper dose of resistance exercise, which may vary for different health outcomes and populations," he continues.
Over 30 percent lower risk of diabetes
For this study, the scientists used the data of 4,681 adults aged 20–100, none of whom had diabetes at baseline. They accessed this information through the Aerobics Center Longitudinal Study. All the participants agreed to do chest and leg presses to allow the researchers to measure individual muscle strength.
To provide more accuracy, the investigators also adjusted these measurements for several potentially confounding factors, including age, biological sex, and body weight. All the participants also completed relevant health exams both at baseline and at the follow-up stage.
The researchers found that those who exhibited moderate muscle mass had a 32 percent lower risk of type 2 diabetes. This effect appears independently of other lifestyle factors, such as frequent drinking and smoking, as well as of obesity and high blood pressure — both of which are risk factors for diabetes.
Still, the investigators were unable to obtain detailed information about all the participants' resistance training habits. However, the data they managed to collect from one small group suggested that there may be a moderate association between a person's muscle strength and how often they participate in this type of exercise.
"You're not necessarily going to see the results of resistance training on your bathroom scale," cautions study co-author Angelique Brellenthin, "but there are several health benefits."
She adds that "[i]t may help lower your risk for type 2 diabetes even though you do not lose body weight, and we know maintaining muscle mass helps us stay functional and independent throughout life."
Brellenthin acknowledges that so far, it remains unclear just how often, and at what intensity, a person should engage in resistance training to lower their diabetes risk. Future studies will need to address this gap.
Despite this, she points out that the recent findings suggest that even a little resistance training is, most likely, better than none at all, and that people should not feel as though they have to jump right into the most difficult exercises to reap the benefits.
"We want to encourage small amounts of resistance training and it doesn't need to be complicated. You can get a good resistance workout with squats, planks, or lunges. Then, as you build strength, you can consider adding free weights or weight machines."