Movement
Walking, training, strength, fitness and sitting: what moving the body does, and how much it takes.
Brisk walking led at all three bone sites. At the hip, on three trials.
Pooling 124 randomised trials and 18,429 adults aged 40 and over, a BMJ network meta-analysis ranked six kinds of exercise against non-exercise controls for bone density at the spine, the femoral neck and the hip. Brisk walking or jogging came top at all three, adding 0.013 g/cm2 at the lumbar spine, and the dose-response curve put a clinically meaningful gain at around 600 METs-min a week, roughly 2 to 3 hours of it. The authors rate their own confidence low to moderate, and say several small walking trials reported outsized effects.
Four kinds of movement, two directions
A pooled analysis of 74 studies and 4,227,297 adults split physical activity by where it happens. Leisure-time activity sat alongside a 24 percent lower risk of dementia. Physical work sat alongside a 20 percent higher one. The certainty of that evidence, the authors say, is very low to low.
The exercise and depression result is weaker than the headlines said
A Cochrane review of 73 trials was reported as showing exercise rivals therapy. Read the trials it rests on and the picture is thinner, and the review says so itself.
A chair, a cone, and seven years of death records
Taiwan measured 13,423 adults aged 65 and over on seven simple fitness tests, then followed them through the national death registry for a median of seven years. The fittest fifth died at a rate 61 percent below the least fit. What the study cannot say is whether getting fitter is what makes the difference.
