YOUTH MARATHON TRAINING: INJURY EPIDEMIOLOGY & RISK FACTORS

Abstract

Background Youth participation in long distance running has increased yet little data exist about the injury patterns and safety of such activity. There are inherent training challenges in youth athletes that theoretically increase their risk of injury relative to their adult counterparts. These include their ongoing neuromuscular development and evolving gait, vulnerable growth open plates, increasing limb length that outpaces muscle growth, and reduced heat tolerance. Students Run LA (SRLA), now in its 30th year of operation, is a non-profit organization that mentors youth during an eight-month marathon training program. While there are many program benefits, little is known about the safety of distance running in adolescent athletes. This study sought to determine the types and rates of injuries in a subset of SRLA participants. Methods & Study Design From August 2017 - March 2018, weekly injury reports were digitally collected by volunteer coaches. Data collection included demographics, injury type, severity, acuity, time off and training mileage. Results 50 high schools and 34 middle schools participated, representing 1930/2750 (70.2%) of total SRLA participants. Mean age was 15 (SD 1.9). 1922/1930 (99.6%) completed the marathon. 411 injuries occurred in 353/1930 (18%) runners during the training program. HS runners were more likely to be injured than MS runners (20.8% vs. 14.2%, p<0.001). There was no difference in injury rates between male and female runners (46.7% vs. 53.2%, p=0.153). 72% of injuries were acute, 16% were subacute, 3% chronic, and 9% unspecified. 60.1% of injuries were associated with time off with a mean time off of 4.8 days (SD 4.8). The most frequent sites of injury were the knee (33%), leg (19%), ankle (15%), and foot (14%). Overall, runners with injuries ran significantly more miles per week than uninjured runners (14.6 vs. 12 .0, p<0.001), a pattern that was consistent at the MS (14.1 vs. 11.6, p<0.001) and HS levels (15 vs. 12.1, p<0.001). Conclusions 18% of youth marathon participants reported an injury over the course of an 8-month training program. The majority of injuries were acute. There was no significant difference in injury rates between males & females but HS runners were more likely to be injured than MS runners. 99.6% of study participants successfully completed the marathon, a higher completion rate than seen in adults. Significance This study represents one of the largest descriptions of injury prevalence in youth distance running. The results highlight an injury rate in youth runners comparable to adults during a marathon training program and a race completion rate that is higher than adults. These findings may lead to changes in the current Position Statement with regard to youth marathon participation. Acknowledgements Orthopedic Institute for Children Students Run LA