Weight training and aerobic exercise can help control diabetes

If you have type 2 diabetes, weight training can help control your blood glucose levels, as can aerobic exercise such as jogging or cycling, according to a new study. Doing both types of exercise may work even better and help protect your long-term health.

What do we know already?

Diabetes means you have too much glucose in your blood. Type 2 diabetes tends to affect people later in life, usually after 40. Diet and exercise can help control your glucose levels at first, but many people eventually need to take tablets and some need to take insulin. Diabetes can cause serious health problems, especially if blood glucose levels stay high over a long period of time.

Doctors use a test called the haemoglobin A1c blood test (HbA1c for short) to see how well your diabetes has been controlled over the previous two or three months. Haemoglobin A1c is a chemical found in your blood. If your blood glucose level is often higher than normal, you will also have a high haemoglobin A1c level. A good result is 7 percent.

We know that reducing your haemoglobin A1c level by 1 percent (say from 8.5 percent to 7.5 percent) is associated with a reduced risk of having a heart attack and stroke and of getting eye and kidney problems.

Previous research has found that aerobic exercise (such as walking, jogging or cycling) and weight training (also called resistance exercise) both help to keep glucose levels down.

When you lift weights or work with weight machines you work on specific muscle groups to increase muscle strength. Aerobic exercise involves continuous activity of the large muscle groups, such as the leg muscles. It also makes your heart and lungs work harder, making you stronger and fitter.

The present study was done to see if doing both aerobic exercise and weight training helps control diabetes better than doing just one type of exercise.

What does the new study say?

Doing either weight training or aerobic exercise helps to improve diabetes control. But doing both types of exercise seems to have the greatest benefit.

In the study, haemoglobin A1c values fell by about 0.5 percent in people who did three, 45-minute sessions of either aerobic exercise or weight training every week for six months. Among people who did both aerobic exercise and weight training (six 45-minute sessions each week) haemoglobin A1c levels fell by almost 1 percent. Those who did no exercise had no change in haemoglobin A1c.

Where does the study come from?

The study was done by researchers from the University of Ottawa and the University of Calgary in Canada. It was published in a journal called the Annals of Internal Medicine.

How reliable are the findings?

This was a good study. It followed 251 people with type 2 diabetes for six months, which is a good length of time to see the effects of exercise.

But there was one big problem with this study. People who did just one type of exercise did half the amount of exercise each week (three 45-minute sessions) as people who did both weight training and aerobic exercise (who did six 45-minute sessions each week). This means we don’t know whether the group of people who had the best diabetes control had it because they did both types of exercise, or because they worked out for longer. The study would have been better if all the people spent the same amount of time each week exercising.

What does this mean for me?

This study is important if you have type 2 diabetes. It has found that taking plenty of exercise can lower your blood glucose, and that weight training is just as good as aerobics. Because it just looked at people who were taking drug treatment for type 2 diabetes, we can’t say if the findings apply to people who are taking insulin.

What should I do now?

If you have type 2 diabetes and you do not get much exercise, you should think about starting to exercise regularly. Choosing the exercise you enjoy is important, since you’re more likely to stick to an activity you enjoy, and aerobic exercise and weight training both seem of equal benefit. Doing both types may help even more, but we can’t be certain. What seems to be important is doing quite a lot of exercise and to keep doing it.