The first study used accelerometers to monitor 7 days of physical 
activity (light or moderate in intensity) among some 1800 adults over 
age 49 who had knee osteoarthritis or were at risk for it. At 2 years’ 
follow-up, even light-intensity activities were significantly related 
to avoidance of disability onset or progression.

The second study examined the prognostic value of grip strength, chair-
rise speed, and standing balance in some 2800 adults (age at baseline, 
53 years) followed up after 13 years. Those in the lowest quintile of 
composite scores had nearly quadruple the risk for all-cause 
mortality, compared with those in the highest quintile of achievement.

To avoid disability or early death, an editorialist suggests that 
increasing light activity by over an hour a day (say, by walking 
around during television commercials) “might do the trick.”

BMJ study on knee arthritis