ration and intensity of exercise, and distance covered (if appropriate to the type of exercise). This provided exposure data or denominator data for calculating injury rates. The subjects also recorded on an Injury/Illness Report Form any injury or illness that: a) required formal or informal medical attention, and/or b) resulted in modification or restriction of normal activities for the remainder of that day or one or more days beyond the date of onset. These check-off forms collected data regarding the site, nature, circumstances and severity of the injury. The forms were returned at the end of each month using the stamped, self-addressed envelopes provided. Upon receipt in the project office, the forms were logged in and screened for completeness and logical consistency. Subjects were contacted regarding missing forms or data, or any questionable entries on the forms. After screening, the data from the forms were entered into computer files for storage and later analysis using locally developed software. Subjects completed and returned these forms for a six month period (1 January 1990 - 30 June 1990).Forms were received from all 25 subjects for each of the six months of this pilot study. The subjects accumulated 3,209 exercise sessions totaling 2,631 hours, averaging nearly 5 sessions per week of about 50 minutes per session. Table 1 summarizes the amount of exercise activity in this sample, and provides a breakdown by gender and age group. In this particular sample, running/jogging comprised two-thirds of the exercise sessions (Table 2). Twenty-one of the subjects ran regularly, averaging nearly 4 sessions per week, 50 minutes per session, and 9.3 km per session at a pace of 5:24/km. Table 2 summarizes the exposure data for the three predominant activities (running, walking and weightlifting), and the cumulative totals for the other exercise activities, which included swimming, cycling, tennis, aerobics, rowing, stair climbing, wa...
