New research sheds light on why people tend to move slower as they age.

As people age, their movements naturally slow down. New research suggests that older adults may move slower because it requires more energy for them than for younger adults. Scientists believe these findings could lead to new diagnostic tools for diseases such as Parkinson’s and multiple sclerosis.

It's well-known that aging bodies slow down due to factors like a slower metabolism, loss of muscle mass, and decreased activity. Now, researchers from the University of Colorado Boulder have found that older adults may move slower partly because it costs them more energy than younger adults.

This research, published in The Journal of Neuroscience, could help develop new diagnostic tools for diseases such as Parkinson’s and multiple sclerosis.

Older Adults Slow Their Movements to Conserve Energy

In the study, researchers recruited 84 healthy participants, including younger adults (18 to 35) and older adults (66 to 87). Participants used a robotic arm to reach for a target on a screen. Analysis showed that older adults adjusted their movements to conserve energy, using more muscles to perform the same tasks as younger adults.

“With age, our muscle cells may become less efficient in transforming energy into muscle force and ultimately movement,” explained Dr. Alaa A. Ahmed, senior author of the study. “We also become less efficient in our movement strategies, possibly to compensate for lower strength, which costs more energy.”

The Brain’s Reward Circuit and Movement

The researchers also examined how aging affects the brain's “reward circuitry,” as the body produces less dopamine with age. Using the robotic arm, participants were rewarded with a "bing" sound when they hit a target. Both younger and older adults responded to the reward, but older adults started their movements slightly sooner to achieve the same results, indicating some preservation of the reward circuitry.

“While older adults were similarly sensitive to reward as young adults, they were much more sensitive to effort costs than younger adults, suggesting age has a stronger effect on sensitivity to effort than to reward,” noted Dr. Ahmed.

Potential for New Diagnostics for Parkinson’s and MS

Researchers believe their findings could lead to new diagnostic tools for movement-related disorders. “Movement slowing as we age can significantly impact our quality of life,” said Dr. Ahmed. Understanding the underlying causes can help identify potential interventions.

Movement speed could serve as a valuable biomarker for neurological health, providing insights into various disorders beyond just movement-related ones.

More Studies on the Aging Brain and Movement Needed

Experts agree that more research on the aging brain and movement is necessary. Clifford Segil, DO, a neurologist, emphasized the benefits of encouraging elderly patients to stay active despite the higher energy costs.

Ryan Glatt, CPT, NBC-HWC, highlighted the need for direct neurological evidence linking movement patterns with brain function changes due to aging. Future research should aim to directly correlate behavioral data with neurophysiological evidence and include larger, more diverse samples to validate these findings.

This research offers an intriguing hypothesis linking slower movements in older adults to energy conservation and reward processing, with potential applications in diagnosing and understanding age-related neurological disorders.