Your Circadian Rhythm: The Importance of Activity

            The benefits of exercise are common knowledge to everyone; we know how integral it is to maintain our health and to ensure a healthy lifestyle. Exercise is known to be highly necessary in order to make sure our body’s systems continue functioning at an optimal level. But this is only one of the benefits of exercise. Research has now found that exercise can have positive influences for our built-in body clocks, recognizing what times are optimal for movement and when it is not. In a study conducted by Dr. Scheer et al. at Leiden University in the Netherlands, they found when researching with rats that exercise affects daily movement patterns more than age does and can have more influences on one’s circadian rhythm.

            The study used mice ranging in age from six months old (considered young adults) to two years old (considered old age), placing them in cages where sensors could monitor their physical activity. Their cages contained a running wheel, which they could run on at their own will, and their activity was monitored for a month. The researchers found that the young rats, unsurprisingly, ran quite a bit on the wheel and had clear distinctions between day and night in terms of their internal clock and physical activity. The older rats followed a similar trend, but with less intense peaks. When the researchers removed the wheels to test their activity, they found the rats would have random periods of movement, sometimes during a time when they would normally be at rest if the wheel were still present. They also found that the young and old rats had very similar activity patterns and differences between the two groups’ activities were less distinct. Returning the wheel to the cages showed both groups returning to the activity trends that were found initially.

            These results show that with the release of certain biochemicals in the body and brain, exercise clearly affects the circadian rhythm and internal body clock mechanisms in these animals. Physical activity appears to allow the body to be a better judge of when it should be active versus when it should be at rest.

            Understanding these findings of the importance of the circadian rhythm can be applied to understanding the specific mechanisms behind internal body clocks. This study, coupled with the research done by Dr. Cavanaugh at Loyola University Chicago, can provide a greater basis of understanding of the circadian rhythm system. In his research, Dr. Cavanaugh examined the pathways undertaken by certain behaviors coupled with the internal clock through examining Drosophila flies. He found that the pars intercelebralis (PI) neurons are important in determining the rest/activity rhythms of the internal clock. Along with other components, the researchers were able to identify a circuit pathway through which the circadian rhythm would be modulated.

            Any further research concerning circadian rhythms could prove beneficial to understanding our human body functioning, as well as assisting those that suffer from various parasomnias or dyssomnias.

References:

Reynolds, Gretchen. “Lack of Exercise Can Disrupt the Body’s Rhythms.” New York Times. 20 May 2015.

Cavanaugh D., Geratowksi J., Wooltorton J., Spaethling J., Hector C., Zheng X., Johnson E., Eberwine J., Sehgal A. Identification of a circadian output circuit for rest:activity rhythms in Drosophila. 24 April 2014. 689-701.

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