Background Firefighting is a hazardous profession and firefighters suffer workplace injury at a higher rate than most US workers. Decreased physical fitness is associated with injury in firefighters. A physical fitness intervention was implemented among Tucson Fire Department recruit firefighters with the goals of decreasing injury and compensation claims frequency and costs during the recruit academy, and over the subsequent probationary year.

Methods Department injury records were analysed and described by body part, injury type and mechanism of injury. Injury and workers’ compensation claims outcomes from the recruit academy initiation through the 12-month probationary period for the intervention recruit class were compared with controls from three historical classes.

Results The majority of injuries were sprains and strains (65.4%), the most common mechanism of injury was acute overexertion (67.9%) and the lower extremity was the most commonly affected body region (61.7%). The intervention class experienced significantly fewer injuries overall and during the probationary year (p=0.009), filed fewer claims (p=0.028) and experienced claims cost savings of approximately US$33 000 (2013) from avoided injury and reduced claims costs. The estimated costs for programme implementation were $32 192 leading to a 1-year return on investment of 2.4%.

Conclusions We observed reductions in injury occurrence and compensation costs among Probationary Firefighter Fitness (PFF-Fit) programme participants compared with historical controls. The initiation of the PFF-Fit programme has demonstrated promise in reducing injury and claims costs; however, continued research is needed to better understand the programme's potential effectiveness with additional recruit classes and carryover effects into the recruit's career injury potential.