Small Doses of Exercise Kept Blood Sugar in Line

Blood sugar control achieved through short bursts of high intensity exercise

(RxWiki News) People who are insulin resistant are unable to turn their blood sugar into energy and can be at risk for diabetes. It’s possible that significantly better blood sugar control can be achieved with a few simple steps.

A recent study found that in patients with insulin resistance, brief periods of high-intensity exercise before breakfast, lunch and dinner improved blood sugar control for the day of exercise and the day after, compared to one prolonged period of moderate exercise before dinner.

The researchers believe that these brief exercise periods — also known as "exercise snacks" — can help prevent diabetes and other cardiometabolic diseases (heart disease and conditions that affect the body's metabolism).

"Discuss your exercise routine with a doctor."

The lead author of this study was Monique E. Francois, teaching fellow and research assistant from the School of Physical Education, Sport and Exercise Sciences at the University of Otago in Dunedin, New Zealand.

The study included nine adults aged 18 to 55 years old with insulin resistance. None of the participants were using medication for blood sugar or blood pressure.

The participants’ average age was 48 years old, and the average body mass index (BMI) was 36. BMI is the ratio of a person's height to weight and is used to determine if someone is a healthy weight.

Each participant completed three different five-day exercise interventions in a random order, with the researchers collecting data over the middle three days of each intervention. The third day was the only day of exercise, with the second day considered to be "baseline" and the fourth day considered to be the "day following exercise."

Traditional continuous exercise involved walking on an incline treadmill at a moderate heart rate for 30 minutes prior to dinner.

Exercise snacking involved six one-minute periods of walking on an incline treadmill at near maximum heart rate 30 minutes before breakfast, lunch and dinner.

Composite exercise snacking involved six one-minute periods of walking on an incline treadmill at almost maximum heart rate, alternated with resistance-based exercise 30 minutes before breakfast, lunch and dinner.

The findings showed both exercise snacking and composite exercise snacking decreased the participants’ blood sugar levels by 13 percent at three hours after breakfast and by 17 percent at three hours after dinner compared to traditional continuous exercise.

Across the whole exercise day, exercise snacking and composite exercise snacking lowered post-meal blood sugar levels by 12 percent.

Both exercise snacking and composite exercise snacking kept the participants’ blood sugar levels down for the day after exercise, whereas traditional continuous exercise did not affect the blood sugar levels the day after exercise.

"We found exercise snacking to be a novel and effective approach to improve blood sugar control in individuals with insulin resistance. Brief, intense interval exercise bouts undertaken immediately before breakfast, lunch and dinner had a greater impact on post-meal and subsequent 24 [hour] glucose concentrations than did a single bout of moderate, continuous exercise undertaken before an evening meal," Francois said in a press statement.

"The practical implications of our findings are that, for individuals who are insulin resistant and who experience marked post-meal increases in blood glucose, both the timing and the intensity of exercise should be considered for optimizing glucose control," she said.

This study was published on May 8 in Diabetologia.

The School of Physical Education, Sport and Exercise Sciences and the Dunedin School of Medicine — both at the University of Otago — provided funding.

Review Date: 
May 8, 2014