Hospitals and Healthcare

Walk more and sit less: even light exercise is linked to a lower risk of death

In the 1950s the London busman’s study found that bus drivers developed a higher rate of coronary heart disease than their bus conductor counterparts.Since then, observational studies have repeatedly suggested that sedentary behaviour is bad and physical activity is good for health and longevity. Guidelines recommend at least 150 minutes of moderate intensity or 75 minutes of vigorous intensity aerobic physical activity each week.

Guideline evidence is mostly based on self report of the amount, intensity, and frequency of activity. Self report is, however, open to recall and reporting bias, potentially resulting in underestimation of low intensity activity and overestimation of overall activity. Self reports are also imprecise. Exactly how much activity (and at what intensity) is needed to protect health remains unclear. In addition, sedentary behaviour is emerging as a potentially independent risk factor for adverse health outcomes despite inconsistency in ascertainment of sedentary time.