It’s not your age that’s keeping you from being active or sleeping well, it’s your inactivity. That’s the finding of a new study underscoring the link between physical movement and maintaining the body’s healthy rhythms.
This 24-hour cycle, otherwise known as circadian rhythm, is apparent in both humans and many animals. It is characterized by its affect on everything from our heartbeats, hormones, hunger and alertness to a variety of other mental and behavioral changes, primarily in response to light and darkness.
While sleep patterns have been the main focus of past studies regarding our internal clock system, it may come as a surprise that physical activity also follows a circadian cycle of sorts. After all, we tend to move more when we are awake and lie still when we are asleep.
More broadly, however, is the question of why different patterns arise in regards to the physical memory of individuals. In other words, what is responsible for our differing physical circadian rhythms? Why do some people demonstrate healthy patterns of physical activity (with normal intervals of activity and rest) while others don’t?
One study conducted in 2009 suggested that such rhythmic differences might have to do with age. The study monitored the activity levels of both young and old participants charting the data on graphs.
An article in the New York Times, explains that the scientist found a kind of physical memory in the younger group of participants:
In essence, the young people’s bodies seemed to be somehow remembering and responding to what that body had just been doing, whether sitting or moving, and then calculating a new, appropriate response — moving or sitting. In doing so, the researchers felt, the body created a healthy, dynamic circadian pattern.”
In contrast the charts revealed that this type of physical memory was greatly reduced with age. In other words, the older participants moved less during the day with spurts of random movement throughout the night, all of which indicated a rhythm that was out of whack.
This may appear to be bad news, especially since aging is an inevitable part of life. But not to fret, new evidence reveals that disparities in our physical rhythms are likely to be determined by our activity levels rather than solely by our age.
The study, conducted by Dr. Scheer and his colleagues, including Kun Hu at Harvard and Johanna Meijer at Leiden University in the Netherlands, gathered data from mice ranging in age from young to old. They gave them running wheels and attached sensors to the rodents in order to monitor their activity levels. After a period of time the data showed that the younger mice had healthy patterns of activity with regular peaks and valleys as shown on the charts. The charts for the older mice were in the healthy range but more blunted.
This is where it gets interesting. The scientists then removed the exercise wheels from the cages, leaving both young and old mice with less to do in the way of physical exercise and activity. Within weeks of doing so they found that the charts for both groups (both young and old mice) became much more haphazard. They would run around in circles at random times and sleep outside their normal schedules.
The conclusion that Dr. Scheer drew from this was that exercise releases a variety of biochemicals that affect both the body and the brain. In other words as explained in the same New York Times articles.
…exercise almost certainly affects the body’s internal clock mechanisms and therefore its circadian rhythms, especially those related to activity. Exercise seems to make the body better able to judge when and how much more it should be moving and when it should be at rest.”
Although more research is needed, this would seem to be good news, for while we cannot avoid growing older, we can, at the very least, try to stay active and exercise, thereby keeping our body’s rhythms healthy.
Image via Flickr
Lack of exercise can Disrupt the Body’s Rhythm via NYTimes
Circadian Rhythms Fact Sheet via National Institute of General Medical Sciences.