Strength Training Is Associated With Less Knee Osteoarthritis: Data From the Osteoarthritis Initiative

Objective: We aimed to evaluate the relationship of a history of strength training with symptomatic and structural outcomes of knee osteoarthritis (OA). Methods: This study was a retrospective, cross-sectional study within the Osteoarthritis Initiative (OAI), a multicenter prospective longitudinal observational study. Data were collected at four OAI clinical sites: Memorial Hospital of Rhode Island, the Ohio State University, the University of Pittsburgh, and the University of Maryland/Johns Hopkins. The study included 2,607 participants with complete data on strength training, knee pain, and radiographic evidence of knee OA (male, 44.2%; mean ± SD age 64.3 ± 9.0 years; mean ± SD body mass index 28.5 ± 4.9 kg/m²). We used a self-administered questionnaire at the 96-month OAI visit to evaluate the exposure of strength training participation during four time periods throughout a participant's lifetime (ages 12–18, 19–34, 35–49, and ≥50 years old). The outcomes (dependent variables) were radiographic OA (ROA), symptomatic radiographic OA (SOA), and frequent knee pain. Results: The fully adjusted odds ratios (95% confidence interval) for frequent knee pain, ROA, and SOA among those who participated in strength training any time in their lives were 0.82 (0.68–0.97), 0.83 (0.70–0.99), and 0.77 (0.63–0.94), respectively. Findings were similar when looking at the specific age ranges. Conclusion: Strength training is beneficial for future knee health, counteracting long-held assumptions that strength training has adverse effects.