In brief: An 80-item questionnaire was used to study the variations by age and sex in the training habits and injury experience of 688 adult entrants in a 10-mile road race in southern Ontario. The results showed that runners over the age of 30 years tend to train at a slower pace than younger runners. On the average, men trained over somewhat longer distances and at a faster pace than women of the same age, but women ran more times per week. Older athletes tended toward a higher weekly mileage and entered the longer distance races. While 57% of all respondents reported at least one injury during the 12 months preceding our study, there was no significant variation by age or sex.