Great news for runners and for those thinking about getting active!
Effects of running and walking on osteoarthritis and hip replacement risk
Author: Williams PT
Summary: Exercise increases the risk of injuries, which can increase OA. However, exercise also reduces bodyweight, promotes cartilage thickening and reduces the loss of cartilage proteoglycans, which can reduce OA. Therefore debate continues about whether exercise, and in particular running, is good or bad for OA.
A total of 89,377 runners and walkers were reviewed by questionnaire to investigate this question. This massive cohort is ten times larger than all previous cross-sectional studies on the subject combined. The results showed that running reduced the risk of OA by 18.1% and the risk of hip replacement by 35.1% once energy expenditure exceeded 1.8 MET-hours per day (>12.9 km/wk). Walking showed a similar risk reduction, again once energy expenditure exceeded 1.8 MET-hours per day. Number of marathons run, best time for a marathon or 10km race, running intensity and longest habitual run were unrelated to risk. In contrast, more vigorous nonrunning exercise (>5.4 MET-hours per day) increased OA risk by 21% and hip replacement risk by 99%. BMI was a significant risk for OA, with each BMI point increasing OA risk by 5% and hip replacement risk by 9.8%.
Comment (JM): This large powerful study showed clearly that a moderate level of running or walking helps prevent OA and reduces hip replacement significantly. Roughly half of this protection was due to reductions in BMI. Nonrunning exercise increased the risk of OA, and adjusting for BMI did not alter this relationship, suggesting acute incidents rather than chronic wear may be the issue. Note that MET-hours are calculated by multiplying the METs of an activity (http://www.exrx.net/Calculators/WalkRunMETs.html) by duration.
In other words RUN and then RUN some more and lay off the twisting and contact sports that cause injuries. Keep you weight down and you will live a long and happy pain reduced life! Ashley