Glucose tolerance and physical fitness: an epidemiologic study in an entire community

A modification of the Harvard Step Test was administered to approximately 4700 males and females, age 10-69 in Tecumseh, Michigan. Heart rate response to this standardized exercise test is an estimate of capacity for muscular work. A blood sample was drawn 1 h after a glucose challenge on the same day the exercise test was given. Four skinfolds were measured as an index of body fatnes. It was the purpose of this analysis to study the relationship of glucose tolerance to heart rate response to exercise. All analyses were done in age and sex-specific sub-groups. The correlation coefficients are low but positive in all but one sub-group and half of the coefficients are statistically significant. This suggests that poor fitness for work (high heart rate in response to exercise) was related, albeit weakly, to lowered glucose tolerance. However, there is a positive relationship between body fatness on the one hand and serum glucose and heart rate response to exercise on the other. When the effect of body fatness was eliminated the relationship of heart rate response to exercise ahd glucose tolerance remained about the same; low but statistically significant in some age groups.