Scientists agree that exercise has a beneficial effect on physical health. What effect does exercise have on the ability to think and remember?  Does exercise improve thought processes and protect against memory loss?  Researchers have the answers to these critical questions.

Your brain connects thoughts that allow you to remember and function by utilizing nerve cells.  Scientists know that as a person ages, these nerve cells can become weak and damaged.  Key terms for understanding the effects of exercise on the brain include:

Neuroprotective: Protects nerve cells from damage, degeneration, or impairment in functioning

Exercise: Activity requiring physical effort

Cognitive Decline: Difficulty remembering, learning new things, concentrating, and making decisions

Studies in Mice

Over the last twenty-five years, rodent studies have provided valuable models for understanding how exercise affects cognitive decline. According to a review published in the journal Brain Plasticity, exercise has shown these benefits for memory and the brain:

  • Improved lifecycle of dentate gyrus cells
  • Enhanced synaptic plasticity
  • Increased glymphatic clearance
  • Regulating microglial activation

The dentate gyrus is part of the hippocampus in the brain that contributes to memory formation and curiosity.  Exercise studies in mice show that physical activity improves the amount, quality, and survival of cells in this area.

Synaptic plasticity involves the brain’s ability to move information between nerve cell endings or synapses. Increased plasticity makes memories easier to access.  As cells age and die, the glymphatic system removes the waste from the brain and central nervous system, keeping it healthy and well-functioning.  Microglia in the brain and central nervous system also contribute to waste removal that has neuroprotective effects.

Exercise and Alzheimer’s Disease

Alzheimer’s disease begins with a loss of memory and leads to cognitive decline in language, movement, visual recognition, and decision making. Scientists have determined that neurofibrillary tangles and extracellular waste deposits lead to atrophy or brain cells’ wasting away.  This atrophy is often most prevalent in the hippocampus, which is associated with memory formation. As the brain cells atrophy, memory loss and cognitive decline increase.

Studies published in the European Journal of Neuroscience show that exercise improved brain function and increased cognitive ability.  Studies show that exercise helps protect cognitive function at all stages of Alzheimer’s disease.  Exercise can prevent the early stages, slow progression and is a treatment option for late-stage Alzheimer’s disease.

Scientists believe that the neuroprotective effects of exercise on cognitive decline are a combination of improved cell life and enhanced blood flow to the brain.  Improved blood flow helps increase necessary hormones, energy, and other neuroprotective chemicals in the brain, boosting the brain’s ability to function.

Direct Effects

Exercise has been shown to help protect against cognitive decline in people of every age and throughout life. A study in the Journal of the American Geriatrics Society showed that women who were physically active at any point in their lives, especially when teenagers, showed less cognitive impairment later in life.

A study published in the journal Neurology measured cognitive function in older adults. Over the eight-year study, 30% of the participants showed no change in cognitive function.  These participants were more likely to have engaged in moderate to vigorous exercise.

Another study published in the journal Neurology followed older adults for three and a half years.  Participants with the lowest amount of exercise had a two-fold higher risk of developing Alzheimer’s disease than those who did the most exercise.

Protecting brain function is necessary for limiting cognitive decline as people age. Because of the neuroprotective effects of improved cell life and blood flow to the brain, science has shown that exercise provides substantial benefits against cognitive decline.