Running Marathons in High School: A 5-Year Review of Injury in a Structured Training Program

**Background:** Physical inactivity is a major public health concern, and initiatives like noncompetitive marathon training programs aim to engage adolescents who may not participate in traditional sports. However, concerns about the safety of adolescent marathon running persist, with limited evidence available. A 2003 position statement recommended against adolescent marathon participation due to potential risks to growth and development, but an expert panel in 2006 called for more research. This study aimed to identify the number, nature, and severity of injuries in adolescents participating in a structured high school marathon training program, with an exploratory secondary aim of examining sex-based differences.

**Methods:** This was a retrospective clinical audit of prospectively collected injury data from the DREAMFAR High School Marathon program (Boston, MA, USA) over 5 years. Participants were high school students (grades 9–12) who volunteered without try-outs or fitness requirements. The 30-week program (October–May) included 3 school-based sessions/week (2 running, 1 cross-training) and a weekend long run, with conservative mileage progression (starting at 2–4 miles/week, progressing to 35 miles/week, with no >10% weekly increase). A running-related injury was defined as any self-reported complaint to a physiotherapist. Injuries were classified by type (joint, soft tissue, bone), body part (ankle/foot, lower leg, knee, hip/thigh, spine), and treatment frequency (as a severity proxy). Six licensed physiotherapists assessed and treated participants. Descriptive statistics, independent t-tests, Mann–Whitney U tests, and chi-square analyses were used.

**Key Results:** Over 5 years, 469 students enrolled; 448 (253 girls, 195 boys) completed the program. Seven left due to changed interest; 14 (3%) dropped out due to injury. The overall injury proportion was 39.6% (186/469). Among completers, 172 participants (88 girls, 84 boys; mean age 16.3 ± 1.1 years) reported 226 musculoskeletal injuries. Most participants (143/172, 83.1%) reported a single injury; 25 reported 2 injuries; 4 reported 3 injuries. Two-thirds of injuries (154/226, 68.1%) were soft tissue injuries. The most commonly injured body parts were ankle/foot (70 injuries, 31.0%), knee (58, 25.7%), and lower leg (55, 24.3%). Bone injuries were rare (13/226, 5.8%). No significant differences by sex were found for injury type (χ² p = 0.779) or body part injured (χ² p = 0.167). The mean number of treatment sessions was 1.8 ± 1.6 per participant (95% CI: 1.5–2.0) and 1.9 ± 1.7 per injury (95% CI: 1.6–2.1), with no sex difference (p = 0.293). The most common treatment was physiotherapy alone (29.6%) or combined with running modification (25.2%). Only 4.9% of injuries required referral to an orthopedic specialist.

**Clinical Implications:** This study provides the first prospective documentation of injuries in adolescent marathon trainees. The injury proportion (39.6%) aligns with the lower range reported in adult novice runners (26–85%). Importantly, injuries were generally minor—four in five required only 1–2 treatment sessions—and less severe than those reported in competitive high school cross-country or other high school sports. The low rate of skeletal injuries (5.8%) challenges longstanding concerns about growth plate vulnerability in adolescent distance running. The high completion rate (98%) and low injury-related dropout (3%) suggest that a conservative, graduated, supervised training approach can be safe for adolescents. The authors note limitations including the lack of exposure hours for injury rate calculation, potential underreporting of injuries treated elsewhere, lack of anthropometric or skeletal maturity data, and limited generalizability from a single program. They recommend continued emphasis on conservative training and call for longitudinal studies to assess long-term effects.