It’s one of the inescapable realities of aging: The older we get, the slower we tend to move — whether we’re walking around the block or just reaching for the remote control. A new study performed by researchers at the University of Colorado is one of the first studies to uncover the reason why people over the age of 65 might not be as quick on their feet as they used to be. Researchers reported that older adults may move slower, at least in part, because it costs them more energy than younger people. Why we move the way we do — from eye movements to reaching, walking and talking — is a window into aging, and scientists hope their findings could one day give doctors new tools for diagnosing a range of illnesses. Researchers have long known that older adults tend to be slower because their movements are less stable and accurate, but other factors could also play a role in this fundamental part of growing up. The muscles in older adults may work less efficiently, meaning that they burn more calories while completing the same tasks as younger adults. Aging also alters the reward circuitry in the brain. As people age, their bodies produce less dopamine — a brain chemical responsible for giving you a sense of satisfaction after a job well done. If you don’t feel that reward as strongly, you may be less likely to move to get it. The study also suggests that while older people move slower, they also move smarter. The brain seems to be able to detect very small changes in how much energy the body is using and adjusts our movements accordingly. While more research needs to be conducted, it looks like the brain’s reward center is the culprit behind why we slow down as we age. If scientists can figure out where and how these changes emerge from the body, they may be able to develop treatments to reduce the toll of aging and disease.
