Data was collected on 28 healthy and physically active people with an average age of 25 and an average BMI of 25, who wore an armband to track physical activity that walked an average of 10,000 steps per day. 2 weeks after participants reduced their physical activity by over 80% to around 1,500 steps per day without altering food intake and reassessment was conducted.
According to researchers from the Institute of Aging and Chronic Disease, after just 2 weeks of being more sedentary participants were found to have lost nearly a pound of lean muscle and to have gained body fat which tend to accumulate centrally; fitness levels decreased as participants were not able to run for as long or at the same intensity as before; insulin sensitivity decreased, increased fat accumulated in the liver, triglycerides increased, and mitochondrial function dropped but it was not statistically significant.
“In 14 days we see small, but significant, changes in markers that predispose people to risk. But when everything you measure gets worse in such a short time period, including these important risk factors for heart disease and type 2 diabetes, it is actually quite surprising. Even if those people were at risk, you have to think about what that means for patients who are older or less healthy, or who have other risk factors, like a family history of disease,” says Kelly Bowden-Davies.
“They still went to work or university, or looked after their children, so this is a typical example of what some individuals are doing in society. Even for people who are regularly active, it’s not hard to imagine how some lifestyle change—like a new job or a longer commute—could trigger this type of reduction in walking and other types of regular exercise,” the authors say.
Based on these findings it may only take as little as 14 days of being sedentary for a person to become measurably less healthy. According to this research from the University of Liverpool it only takes 2 weeks without regular physical activity to lead to metabolic and muscular changes that can increase risks for diabetes, heart disease, and even possibly death.
When participants resumed their normal activity after being more sedentary their health measures were found to have returned to normal over the next 2 following weeks. Meaning it is possible to regain what was lost, which is good news.
“The effects were entirely reversible—so it’s fine if you’re fit and well and you go on holiday for two weeks and then you get right back to normal. But the problem is that many people don’t reverse back to these levels of activity, and then perhaps the effects will accumulate. The longer people are inactive, the harder it is to get back into shape, especially for those who already have health issues. Simply being less sedentary and maintaining a high step count has very clear health benefits,” says co-author Dan Cuthbertson, PhD.
