Glucoregulation is more precise in women than in men during postexercise recovery

Background: The regulation of glycemia is challenged in healthy men and women after exercise bouts of substantial energy expenditure. Objective: We determined rates of glucose appearance (Ra), disappearance (Rd), and metabolic clearance (MCR) before, during, and after isoenergetic moderate and hard-intensity exercise. Design: Ten men and 8 women received primed-continuous infusion of [6,6-(2) H-2]glucose tracer to measure glucose kinetics. Participants were studied under 3 different conditions with diet unchanged between trials: 1) before, during, and 3 h after 90 min of exercise at 45% of peak oxygen consumption (<(V) over dot>O(2)peak; E45); 2) before, during, and 3 h after 60 min of exercise at 65% <(V) over dot>O(2)peak (E65), and 3) in a time-matched sedentary control trial. Results: In men and women, Ra, Rd, and MCR increased above the control trial during exercise and were higher in E65 than in E45 (P < 0.05). Average Ra, Rd, and MCR remained elevated above the control over 3 h of postexercise recovery in men after exercise in E45 and E65 (P < 0.05), and blood glucose concentrations were depressed below the control during recovery (P < 0.05). Glucose concentrations were not depressed in women during 3 h of postexercise recovery, and in contrast with that in men, average Ra and Rd did not remain significantly elevated during postexercise recovery in women, although MCR did remain elevated in E65 (P < 0.05). Conclusions: After exercise bouts, women are better able to maintain glucose concentrations at sedentary control levels, thus not requiring the counter-regulation of glucose production that is seen in men and requiring less accentuation of lipid metabolism.