Sitting for hours at a desk can play havoc with our metabolic health, contributing over time to high blood sugar and high cholesterol, even in people who otherwise are mostly healthy.
A new study, published in the American Journal of Physiology-Endocrinology and Metabolism, shows that standing up and moving every 30 minutes for about three minutes may lessen the health impacts of over-sitting.
ACU researchers John Hawley, a leading exercise biologist and director of ACU’s Mary Mackillop Institute for Health Research, and resident sitting expert David Dunstan were part of an international consortium of scientists, led by the Karolinska Institute in Stockholm, involved in the study.
Climbing several flights of stairs, bopping through some jumping jacks or squats or even taking as few as 15 steps during these mini-breaks improved aspects of blood sugar control among office workers, without noticeably interrupting their workflow.
It is well-known that prolonged sitting is detrimental to metabolic health, contributing over time to high blood sugar and high cholesterol, even in healthy individuals.
Research shows every waking hour spent in sedentary postures increases risk for metabolic syndrome and type 2 diabetes but frequent breaks from sitting can improve blood sugar control and cholesterol levels.
The study, which involved 16 middle-aged, white-collar workers at high risk for type 2 diabetes, also indicates that three-minute breaks every 30 minutes likely represent the minimum amount of movement needed to protect metabolic health.
Researchers looked at what would happen if office workers agreed to break up their sitting time, over three weeks, in their normal workplace.
They recruited 16 middle-aged men and women in Stockholm with sedentary desk jobs and a history of obesity, putting them at high risk for metabolic problems like diabetes. They checked the volunteers’ current metabolic health and asked them to wear activity monitors for a week, to get baseline numbers.
Half of the volunteers continued with their normal lives, as a control, and the rest downloaded a smartphone app that alerted them every 30 minutes during the workday to get up and be active for three minutes.
For three weeks, they wandered halls, climbed stairs, marched in place, squatted, hopped or otherwise moseyed about in whatever way they found convenient, tolerable and not overly distracting or amusing to their co-workers but they had to take a minimum of 15 steps before the app recorded their movement as an activity break.
When the participants returned to the lab for another round of metabolic tests, researchers found that the control group displayed ongoing problems with insulin resistance, blood sugar control and cholesterol levels.
The other volunteers, who had stood and moved around while at work, showed lower fasting blood sugar levels in the morning, meaning their bodies better controlled blood sugar during the night, a potentially important indicator of metabolic health. Their blood sugar also stabilised during the day, with fewer spikes and dips than in the control group, and the amount of beneficial HDL (‘good’) cholesterol in their bloodstreams rose.
These improvements were small, but might mean the difference, over time, between progressing to full-blown Type 2 diabetes or not.
Interestingly, the gains also ranged depending on how often and how rigorously workers complied with their app alerts. Those who rose regularly and were the most active – generally managing 75 steps or more during the three minutes – improved their metabolisms the most. Others, accumulating fewer steps, or frequently ignoring their beeping alerts, benefited less.