Background Rates of occupational injuries among firefighters are high because of the physically demanding and variable tasks required by their job. While descriptive data about injuries exist, few studies have explored individual risk factors and their relationship to occupational injury.

Methods The current study presents data from a population-based sample of 462 career firefighters from 11 randomly-selected fire departments in the Missouri Valley region of the USA (Kansas, Missouri, Iowa, North Dakota, South Dakota, Colorado, Wyoming, Nebraska) who participated in a study evaluating risks for negative cardiovascular outcomes and injury. Relationships were examined between injury and demographic characteristics, body composition, fitness, and health behaviours.

Results Participants were most likely to be injured during physical exercise and those who reported regular on-duty exercise had a fourfold increase in risk for exercise-related injury compared with those who did not exercise on duty (OR=4.06, 95% CI 1.73 to 12.24). However, those who exercised were half as likely to sustain non-exercise injuries (OR=0.53, 95% CI 0.32 to 0.85).

Conclusions Findings highlight the benefit of physical training for firefighters despite the risk of injury during exercise.