Take a seat (but only for half an hour at a time)

PEOPLE who exercise but also spend long periods sitting down could be harming their health as much as those who choose not to exercise at all. The astonishing conclusion was revealed in a study last week, leading experts to recommend that people should stand and walk about every 30 minutes

Unexpectedly, the detrimental effects of sitting were apparent regardless of how much time the volunteers who took part in the trial spent exercising.

The Canadian research team followed the activity levels of 278 patients with a coronary heart disease (CHD) who had been through a cardiac rehabilitation programme that had taught them how to improve their fitness by engaging in 24 minutes of moderate-to-vigorous exercise daily.

The patients in the study wore activity monitors that measured how long they were active or sedentary during the day.

On average, eight hours each day were spent sedentary – either sitting or reclining. Regardless of how long the patients might have spent exercising, the researchers found that higher BMI and lower fitness levels were directly associated with the time they spent sitting.

‘It was like a linear relationship,’ said Stephanie Prince, a scientist at the University of Ottawa Heart Institute and lead author of the study. ‘The less time the patients spent sedentary, the better their markers of health.

‘These relationships remained even when we controlled for an individual’s age, gender or physical activity levels,’ she added.

CHD is the single most common cause of death before 65, accounting for 16 per cent of male and ten per cent of all female deaths.

Numerous trials have proven that those diagnosed with CHD who increase exercise have significantly better long-term health.

Prince recommends that patients with cardiovascular symptoms should get up and move every 30 minutes and keep a daily record of their movement.

Patients should aim to break up periods of sitting with movement, she added. Activities could include light stretching or walking. The findings could prove useful to patients who cannot engage in regular moderate exercise.

‘The implications are that perhaps even a modest amount of movement is beneficial,’ Becker says. ‘I think it is incredibly powerful at a societal level, and a public health level, that there are seemingly very small things that a person could do to really protect, and be proactive, about their health.’