Runners have less arthritis (not more) and weight is a major factor
PainSci summary of Williams 2013 ★★★★☆?4-star ratings are for larger and better studies and reviews published in more prestigious journals, with only quibbles. Ratings are a highly subjective opinion, and subject to revision at any time. If you think this paper has been incorrectly rated, please let me know.
This analysis of about a zillion runners versus walkers found that “running significantly reduced arthritis and hip replacement risk”…but due in large part to the fact that runners were typically skinnier. So weight was a trump factor here.
This data flies in the face of the common assumption that running is much harder on the joints. Instead, what it clearly shows is that running is either neutral or helpful, and weight is a much more important factor regardless of whether you walk or run.
PURPOSE: Running and other strenuous sports activities are purported to increase osteoarthritis (OA) risk, more so than walking and less-strenuous activities. Analyses were therefore performed to test whether running, walking, and other exercise affect OA and hip replacement risk and to assess the role of body mass index (BMI) in mediating these relationships.
METHODS: In this article, we studied the proportional hazards analyses of patients' report of having physician-diagnosed OA and hip replacement versus exercise energy expenditure (METs).
RESULTS: Of the 74,752 runners, 2004 reported OA and 259 reported hip replacements during the 7.1-yr follow-up; whereas of the 14,625 walkers, 696 reported OA and 114 reported hip replacements during the 5.7-yr follow-up. Compared with running <1.8 MET·h·d, the risks for OA and hip replacement decreased as follows: 1) 18.1% (P = 0.01) and 35.1% (P = 0.03) for the 1.8- and 3.6-MET·h·d run, respectively; 2) 16.1% (P = 0.03) and 50.4% (P = 0.002) for the 3.6- and 5.4-MET·h·d run, respectively; and 3) 15.6% (P = 0.02) and 38.5% (P = 0.01) for the ≥5.4-MET·h·d run, suggesting that the risk reduction mostly occurred by 1.8 MET·h·d. Baseline BMI was strongly associated with both OA (5.0% increase per kilogram per square meter, P = 2 × 10) and hip replacement risks (9.8% increase per kilogram per square meter, P = 4.8 × 10), and adjustment for BMI substantially diminished the risk reduction from running ≥1.8 MET·h·d for OA (from 16.5%, P = 0.01, to 8.6%, P = 0.21) and hip replacement (from 40.4%, P = 0.005, to 28.5%, P = 0.07). The reductions in OA and hip replacement risk by exceeding 1.8 MET·h·d did not differ significantly between runners and walkers. Other (nonrunning) exercise increased the risk of OA by 2.4% (P = 0.009) and hip replacement by 5.0% per MET·h·d (P = 0.02), independent of BMI.
CONCLUSIONS: Running significantly reduced OA and hip replacement risk due to, in part, running's association with lower BMI, whereas other exercise increased OA and hip replacement risk.
These three articles on PainScience.com cite Williams 2013 as a source:
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