By Regina Schaffer
Men with excess weight or type 2 diabetes may reap more pronounced metabolic benefits from exercise when training is performed in the afternoon vs. morning, according to findings from a small, retrospective study.
“Exercise is the cornerstone for the prevention and treatment of metabolic diseases like diabetes,” Patrick Schrauwen, PhD, professor of metabolic aspects of type 2 diabetes in the nutrition and movement sciences department at Maastricht University in the Netherlands, told Healio. “If our results are confirmed in follow-up studies, it suggests that exercising in the evening may further help to optimize the beneficial effects of exercise.”
In a retrospective study, Mancilla and colleagues compared the metabolic health effects of morning vs. afternoon exercise training among 32 men with overweight or obesity, nonalcoholic fatty liver disease or type 2 diabetes enrolled in a 12-week exercise training program (mean age, 59 years). Men performed supervised aerobic-type and resistance-type exercise training either in the morning (8-10 a.m.; n = 12) or in the afternoon (3-6 p.m.; n = 20) 3 days per week.
“The study was not designed to investigate the effect of the timing of exercise, and the reason for subjects performing exercise in the morning or evening was depending on the scheduling possibilities and personal preferences,” the researchers wrote.
Researchers assessed maximal workload and maximal aerobic capacity during a graded cycling test with ECG monitoring before, during and after exercise; body composition was assessed via DXA. Participants maintained their regular dietary behavior throughout the study. A two-step hyperinsulinemic-euglycemic clamp was performed before and after the training period.
Researchers found that, compared with participants who trained in the morning, participants who trained in the afternoon experienced greater beneficial effects of exercise training on peripheral insulin sensitivity (mean, 5.2 vs. –0.5 mol/min/kg fat-free mass; P = .03), insulin-mediated suppression of adipose tissue lipolysis (–4.5% vs. 5.9%; P = .04), fasting plasma glucose levels (–0.3 vs. 0.5 mmol/L; P = .02), exercise performance (0.4 vs. 0.2 workload/kg; P = .05) and fat mass (–1.2 vs. –0.2 kg; P = .03).
Exercise training in the afternoon also tended to elicit greater effects on basal hepatic glucose output, the researchers wrote.
“The greater improvements in peripheral insulin-stimulated glucose disposal observed upon exercise training in the afternoon could primarily be attributed to increased insulin-stimulated glucose oxidation and was paralleled by greater improvements in fasting plasma glucose levels and exercise performance,” the researchers wrote. “In addition, a superior decline of fat mass was found upon exercise training in the afternoon compared to morning exercise training. Together, these data provide evidence in humans that the timing of exercise may amplify the beneficial health effects of exercise training.”
For more information:
Patrick Schrauwen, PhD, can be reached at firstname.lastname@example.org.