Exercise type & timing key to blood glucose control in type 2 diabetics
We all know about the health benefits of exercise. They’ve been drummed into us for, well, forever. A new study has found that for type 2 diabetics, certain types of exercise and when in the day they’re done may be more effective at controlling blood glucose levels.
In type 2 diabetes (T2D), the body becomes resistant to insulin’s normal effects and the pancreas gradually loses the ability to produce enough insulin to control blood glucose levels. In short, it’s a combination of ineffective insulin and not enough of it.
Long-term elevated blood glucose levels can affect many organs and lead to heart and blood vessel disease, nerve and eye damage, kidney disease and impaired healing. Especially early in the disease, T2D may be managed with healthy eating and regular physical activity. But, even in the long-term, regular exercise has been shown to improve short- and long-term blood glucose (glycemic) control.
A new study by Rutgers University has examined the benefits of physical activity on glycemic control in type 2 diabetics, including whether the time of day makes a difference.
“The challenge with this is that most, if not all, people know exercise is good for them, but they don’t know the best approach,” said Steven Malin, corresponding author of the study.
The researchers pored over dozens of previous studies looking at the effects of aerobic exercise, resistance training, high-intensity interval training (HIIT), exercising before and after meals, and breaking up sedentary activity with physical activity.
Aerobic exercise is a physical activity that increases the heart rate and the body’s use of oxygen, such as brisk walking, swimming, running, or cycling. Resistance training improves muscular strength and endurance by exercising a muscle or muscle group against external resistance, such as dumbbells, resistance bands, or any other object that causes the muscles to contract, including a person’s body weight. HIIT involves short bursts of intense exercise alternated with brief, low-intensity recovery periods.
They found that doing 150 minutes per week of moderate to vigorous physical activity – aerobic plus resistance exercise – over three to five days could reduce T2D risk factors. While exercising in 30- or 60-minute blocks was advantageous, they found that breaking up sedentary behavior with hourly bursts of up to three minutes or 10 to 15 minutes of exercise a few times per day may be equally effective for blood glucose control, particularly after meals. If exercising in a single session, studies suggested that exercising in the afternoon rather than the morning produced better blood glucose levels.
“In short, any movement is good and more is generally better,” said Malin. “The combination of aerobic exercise and weightlifting is likely better than either alone. Exercise in the afternoon might work better than exercise in the morning for glucose control, and exercise after a meal may help slightly more than before a meal.”
The researchers also found that exercise's health benefits should focus on more than losing weight.
“And, you don’t have to lose weight to see the benefits of exercise,” Malin said. “That is because exercise can lower body fat and increase muscle mass.”
The researchers say their study was designed to offer up-to-date, practical advice to medical professionals treating patients with T2D.
“[P]hysicians and healthcare providers should encourage exercise and physical activity as a tool to improve/manage glycemia, independent of weight loss, for enhanced health and wellness,” the researchers said.
The study was published in the American Journal of Medicine Open.
Source: Rutgers University