Moderate, vigorous exercise improved beta cell function

Both moderate- and vigorous-intensity exercise training led to improvements in beta cell function among sedentary, overweight adults in a new study.

Researchers assessed data from the Studies of a Targeted Risk Reduction Intervention through Defined Exercise (STRRIDE) relevant to beta cell function. Study participants included 237 sedentary, overweight or mildly obese and moderately dyslipidemic adults aged 40 to 65 years. All women were postmenopausal.

The researchers randomly assigned participants to a control group (inactive) or to one of three training groups for eight months: high-amount/vigorous-intensity exercise group (n=64), low-amount/vigorous-intensity exercise group (n=58) or a low-amount/moderate-intensity exercise group (n=57).

Exercise intensity, beta cell function

Disposition index significantly improved for the low-amount/moderate-intensity and high-amount/vigorous-intensity groups.

All three exercise groups showed significant improvements in insulin sensitivity; the magnitude of improvement for the moderate-intensity group was significantly greater when compared with the same amount of exercise at a vigorous intensity.

All three groups also had significant reductions in triglycerides; however, the low-amount/moderate-intensity group had the greatest decrease (P<.035) — this trended toward a greater decrease when compared with the high-amount group (P<.085).

Significant improvements in peak oxygen consumption were reported in all exercise training programs.

Participants in the inactive control group had a significant increase in fasting glucose and significant decline in fasting insulin, homeostasis model assessment, BMI, visceral fat and cardiovascular fitness.

“It is not clear which of these mechanisms is preferable for maintenance of metabolic health,” the researchers wrote. “While moderate-intensity exercise led to a larger improvement in disposition index, which may reflect a transition toward a more normal disposition index, longer-term investigations would be necessary to determine which was more effective at reducing diabetes risk.”

Slentz CA. Diabetes Care. 2009; 32:1807-1811.