TOPLINE:
Strength training at any point in life is associated with a lower risk of knee pain and osteoarthritis, contrary to persistent assumptions of adverse effects.
METHODOLOGY:
- Researchers reviewed data on strength training and knee pain from 2,607 adults. They used the Historical Physical Activity Survey Instrument to assess the impact of strength training during four periods (ages 12-18 years, 19-34 years, 35-49 years, and 50 years and older).
- The participants were enrolled in the Osteoarthritis Initiative, a multicenter, prospective, longitudinal study; 44% were male, the average age was 64.3 years, and the mean body mass index was 28.5 kg/m2.
- Strength training was defined as those exposed and not exposed, as well as divided into low, medium, and high tertiles for those exposed. A total of 818 individuals were exposed to strength training, and 1,789 were not exposed to strength training.
- The primary outcomes were frequent knee pain, radiographic OA (ROA), and symptomatic radiographic OA (SOA).
TAKEAWAY:
- The study is the first to examine the effect of strength training on knee health in a community population sample not selected for a history of elite weight lifting.
- Overall, strength training at any point in life was associated with lower incidence of frequent knee pain, ROA, and SOA, compared with no strength training (odds ratios, 0.82, 0.83, and 0.77, respectively).
- When separated by tertiles, only the high-exposure group had significantly reduced odds of frequent knee pain, ROA, and SOA, with odds ratios of 0.74, 0.70, and 0.69, respectively. A dose-response relationship appeared for all three conditions, with the lowest odds ratios in the highest strength training exposure groups.
- Findings were similar for different age ranges, but the association between strength training and less frequent knee pain, less ROA, and less SOA was strongest in the older age groups.
IN PRACTICE:
“Our findings support the idea that the medical community should proactively encourage more people to participate in strength training to help reduce their risk of osteoarthritis and other chronic conditions,” the researchers write.
SOURCE:
The study, with first author Grace H. Lo, MD, of Baylor College of Medicine, Houston, and colleagues, was published in Arthritis and Rheumatology.
LIMITATIONS:
The observational design and self-selected study population of strength training participants might bias the results, including participants’ recall of their activity level levels and changes in exercise trends over time. More research is needed to explore associations between strength training and knee OA among those who started strength training at a younger age.
DISCLOSURES:
The study was funded in part by the VA Health Services Research and Development Center for Innovations in Quality, Effectiveness, and Safety at the Michael E. DeBakey VA Medical Center, Houston, and by donations to the Tupper Research Fund at Tufts Medical Center. The Osteoarthritis Initiative is supported by the National Institutes of Health; private funding partners include Merck Research Laboratories, Novartis, GlaxoSmithKline, and Pfizer. Three authors report having financial relationships with multiple pharmaceutical companies.
A version of this article first appeared on Medscape.com.