As we get older, physical exercise becomes more and more important. The internet abounds with the latest research extolling the multiple benefits of physical exercise for seniors.
For instance, aerobic activity and muscle training have been shown to improve the psychological well-being of elderly people, and even a few minutes of light exercise can increase lifespan and improve brain function.
The benefits of physical activity have long been praised, but what are the effects of physical inactivity? Some studies have shown that having a sedentary lifestyle harms brain health and raises the risk of diabetes and dementia in seniors, while others have suggested that being physically inactive simply makes you age faster.
New research delves into the metabolic effects of physical inactivity for seniors. A team of scientists led by Chris Mcglory — a Diabetes Canada Research Fellow in the Department of Kinesiology at McMaster University in Ontario, Canada — set out to investigate the effects of 2 weeks of inactivity on elderly adults at risk of diabetes.
The findings were published in The Journals of Gerontology.
Harmful effects of inactivity hard to reverse
Mcglory and colleagues examined a group of seniors aged between 60 and 85 who had already been diagnosed with prediabetes.
The researchers asked the study participants to restrict their daily number of steps to fewer than 1,000 for a period of 2 weeks. No more than 1,000 steps per day is the equivalent of being housebound.
During the study period, the researchers monitored the physical activity of the seniors using pedometers and other specialized devices; they also took blood samples and measured the blood sugar levels of the participants.
The research revealed that only days after the study started, the participants' skeletal muscle mass and strength decreased significantly.
Importantly, the researchers also noted that people who had prediabetes quickly displayed signs of full-blown type 2 diabetes, such as insulin resistance.
Additionally, merely returning to a healthy exercise regimen for another 2 weeks was not enough to offset the harmful effects of inactivity, the researchers found.
"We expected to find that the study participants would [develop diabetes], but we were surprised to see that they didn't revert [...] to their healthier state when they returned to normal activity."
Stuart Phillips, who is a professor of kinesiology at McMaster and the senior investigator of the study, also comments on the findings, saying, "Treatment of type 2 diabetes is expensive and often complicated."
"If people are going to be off their feet for an extended period they need to work actively to recover their ability to handle blood sugar," Prof. Phillips continues.
Mcglory echoes the same feelings and adds, "In order for [older adults with prediabetes] to recover metabolic health and prevent further declines from periods of inactivity, strategies such as active rehabilitation, dietary changes, and perhaps medication might be useful."
In the United States, over 84 million adults are currently living with prediabetes and another 23.1 million received a formal diagnosis of diabetes, so these findings could be relevant for a significant part of the population.