Volunteers (986) from fitness clubs and studios were recruited and fol
lowed for a 3-month period to document the injury consequences of adul
t recreational fitness participation. Participants were telephoned eac
h week and their activities as well as any injuries that occurred were
recorded. Of the 525 injuries and complaints reported during 60,629 h
ours of activity, 475 occurred as a result of sports participation for
an overall rate of 7.83 per 1000 hours of participation. Seventy-six
percent of these episodes caused the patient to alter or miss 1 or mor
e activities, while 9.5% involved a physician visit. The rate for time
-loss injuries was less than 2 per person per year (1.76 per 298 hours
) or 5.92 per 1 000 hours. Running had a higher risk of injury compare
d with most other individual sports. Cardiovascular fitness activities
had low to medium rates, as did weight work; competitive sports were
higher. For 6 of the most commonly injured areas, the reinjury rate wa
s about twice that reported for those with no history of previous inju
ry. The risks of injury from most recreational fitness activities were
relatively modest, particularly if the activities were not competitiv
e. Physicians might help patients reduce their risks of injury by enco
uraging suitable activities and by reducing the risks of reinjury by i
mplementing appropriate rehabilitation programs.