Warning signs of Injury: Changes in pain, training load, and wellness in elite youth athletes

Objectives Examine week-by-week changes during the four weeks preceding injury compared with injury-free weeks. Design Prospective study. Setting and main outcome: Training load was calculated as (weekly training minutes x average weekly rate of perceived exertion)/1000 (sRPE). Pain was assessed with a rating scale 0-10. Wellness (sleep, fatigue, stress and mental recovery) were standardized using Z-scores. Injury was self-reported. Participants Elite youth athletes. Results Among 146 athletes, 118 (80.8%) reported 125 injuries. Mean age was 17.0 (SD 0.8). Compared with injury-free weeks, significantly higher pain scores were observed one (md [IQR]: 2.0 [0.0-4.0], p = 0.039) and two weeks (2.0 [1.0-3.0], p = 0.047) prior to injury. Median sRPE was significantly lower three (md [IQR]: 2.30 [0.75-4.20], p = 0.012) and four weeks (2.40 [0.96-3.96], p = 0.011). Sleep, stress and total wellness were significantly lower one week (mean [SD]: −0.348 [1.1], p = 0.004; −0.272 [0.9], p = 0.017; −0.244 [1.0], p = 0.011), while stress also showed reduction two weeks prior to injury (−0.244 [1.0], p = 0.042). Conclusion Changes were observed mainly in the week preceding injury. Increased pain and reduced wellness may serve as early warning signs, while decreased training load may reflect adaptation rather than causation. These findings support injury as a progressive process with detectable warning signs.