Recommending exercise for older people to reduce cardiovascular risk has added benefits for osteoarthritis risk, according to Australian researchers.
They studied the effect of physical activity, in various degrees of intensity, frequency, and duration, on knee structures in a total of 257 healthy adults between the ages of 50 and 79, with no history of knee injury or osteoarthritis.
They used magnetic resonance imaging to study the tibia bone and tibiofemoral joint of the subject's dominant knee, after looking at 10 years of data on their exercise profiles.
Study author Dr Flavia Cicuttini, from the Alfred Hospital in Melbourne, said: 'This is the first study to demonstrate a potentially beneficial effect of walking on the reduction in the risk of bone marrow lesions in the knee.
'Our data suggest that at least 20 minutes once per week of activity sufficient to result in sweating or some shortness of breath might be adequate.'
Arthritis Care & Research (2007) 57: 1261-1268