Abstract

The effect of acute exercise upon serum immunoreactive insulin levels (IRI) and serum glucose concentrations (GC) was studied in groups of middle-aged menof contrasting physical fitness status. Two groups of subjects, one active andone sedentary (both N = 11, mean age 44 years), performed a graded cycle ergometer exercise test in the post-absorptive state. Venous blood samples were taken at rest, during low and high work intensities, and after recovery. The response of serum IRI to exercise was similar in both groups of subjects with significant increases observed during exercise followed by a return to restingvalues during recovery. However, the magnitude of serum IRI response was lowerin the active group. In contrast, the sedentary group demonstrated little or no change in serumGC during exercise, whereas significant increases in serum GC were observed during exercise in the active group. Verf.-Referat