There is growing evidence that prolonged sitting – a common occurrence these days – is harmful to your health, even if you exercise regularly. A team from Columbia University (USA) has now shown in an experimental study that getting out of your chair and walking for just five minutes every half hour can counteract some of the most damaging effects.

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A five-minute walk every half hour

The results of the study, led by Keith Diaz, professor of behavioural medicine at the US university, are published this week in the journal American College of Sports Medicine.

Participants sat in an ergonomic chair for eight hours, getting up only for their prescribed activity of treadmill walking or a bathroom break.

We already knew that prolonged sitting is dangerous to health because it alters the way the body regulates blood sugar levels and creates conditions in the blood vessels that increase blood pressure,” said Diaz.

Unlike other studies that make one or two choices of activity, in this research, the authors tested five different exercises ‘snacks’: one minute of walking after every 30 minutes of sitting, one minute after 60 minutes, five minutes every 30 minutes, five minutes every 60 minutes and no walking.

Each of the 11 adults who participated in the experiment came to Diaz’s lab, where they sat in an ergonomic chair for eight hours, getting up only for their prescribed treadmill activity or a bathroom break. The volunteers were between the ages of 40 and 60, and most did not have diabetes or hypertension.

The researchers made sure these people did not over- or under-exercise and periodically measured their blood pressure and blood sugar (key indicators of cardiovascular health). The volunteers were allowed to work on a laptop, read and use their phones during the sessions and were provided with standardised meals.

Reducing blood sugar and blood pressure
“We found that the optimal amount of movement was walking for five minutes every 30 minutes. This was the dose that significantly reduced both blood sugar and blood pressure”.

Specifically, he adds, “this activity regime lowered peak blood sugar by 58% after eating, compared to sitting all day. This is a really large amount, similar to the reductions that would be seen if someone used insulin injections or diabetes medications to control blood sugar,” Diaz stresses.

The researcher adds that “a light five-minute walk every half hour also reduced blood pressure by 4-5 mmHg. This reduction is similar to what would be expected from daily exercise for six months. With these surprising results, we conclude that this simple activity could counteract some of the more detrimental effects of prolonged sitting.

To take the measurements, participants wore a continuous glucose monitor on the back of their arm. “This device has tiny sensors that automatically measure the amount of glucose in the body every 15 minutes. The volunteers were given the same meals at the same time at each visit, and the monitor allowed us to track blood sugar spikes after each meal,” explains Diaz.

Although it may seem impractical,” he continues, “this work shows that even small walks spread throughout the workday can significantly reduce the risk of heart disease and other chronic conditions.

The team plans to extend the study and is currently testing another 25 walkings ‘doses’ and testing a wider range of people.

Occupational risk
Asked how employers will feel about this recommendation to get up and walk for five minutes every half hour, Diaz says that employers “should recognise that prolonged sitting is an occupational hazard. Until they recognise what is already a scientific certainty, namely that sitting is a major contributor to many chronic diseases and death, it will be difficult to address a major public health problem that has only worsened since the covid-19 pandemic.

In addition to the physical health benefits of these regular short walks, we also observed positive mental health effects.

He stresses that his study “provides clear guidance to employers on how to promote a healthier workplace. And we know that healthy employees are more efficient and productive”.

“In addition to the physical health benefits of these regular short walks, we also observed positive effects on mental health”. This activity reduced feelings of fatigue and improved mood, Diaz notes, “so taking these short walks can help you be more productive than working non-stop”.

“Employers should therefore recognise that taking regular walking breaks can be hugely beneficial – treating it as unproductive work time is ultimately short-sighted, failing to recognise its value for health and productivity,” he concludes.