Figure 1

The average weekly distance ran was generally similar during the course of the study, and body weights between runners and non-runners did not diverge until after 4 months. A. There was no significant variation in mean weekly distance ran, except for the 3rd week, which was significantly greater compared with the 9th week. B. Body weights of both runners and non-runners were measured weekly during the 5 month running period. A trend but non-significant change in body weights between the two groups was first observed during the last week of the fourth month (P = 0.06), followed by a significant change the first week of the fifth month (P = 0.02).