Older adults who completed a year of moderate or heavy resistance training showed MRI-based brain-age estimates 1.4 to 2.3 years younger than those in a non-exercise group, according to a study published in GeroScience.
By yourNEWS Media Newsroom
Older adults who regularly performed resistance training for one year showed signs of slower biological brain aging compared with participants who did not exercise, according to a study published in GeroScience.
Researchers analyzing 309 participants from the LISA1, or Live Active Successful Aging, trial found that both moderate-intensity and heavy resistance training were associated with reductions in estimated brain age.
Using MRI scans and brain-aging models, researchers calculated differences between participants’ chronological ages and biological brain-age estimates. Compared with the non-exercise control group, participants assigned to resistance training demonstrated brain-aging differences equivalent to approximately 1.4 to 2.3 years.
The findings do not mean participants literally became younger or prove that strength training prevents neurological disease. Brain-age clocks are research tools that analyze patterns in MRI data to estimate whether a brain appears biologically older or younger than expected for a person’s chronological age.
Participants were divided into three groups: heavy resistance training, moderate-intensity resistance training and a control group that did not participate in the exercise intervention.
Both resistance-training groups showed significant effects on estimated brain aging compared with controls.
Researchers also identified changes in brain connectivity among participants performing heavy resistance training. That group demonstrated increased functional connectivity involving the prefrontal cortex, an area involved in executive functions including planning, decision-making, attention and cognitive control.
The researchers said the finding could indicate improved communication among brain regions involved in higher-level cognitive tasks.
Resistance training may affect the brain through several biological pathways.
Exercise increases circulation, which can improve delivery of oxygen and nutrients throughout the body, including the brain. Researchers have also examined whether resistance exercise influences brain-derived neurotrophic factor, or BDNF, a protein involved in neuron survival, growth and adaptability.
Another possible pathway involves inflammation. Chronic inflammation has been associated with aging and several diseases, including conditions affecting cognitive function. Regular physical activity can influence inflammatory processes and other metabolic factors associated with brain health.
Researchers noted that the changes observed in the study were not limited to one isolated brain region. Some of the MRI-based findings appeared across the brain, suggesting that the potential effects of resistance training may extend beyond individual neural networks.
Previous exercise research has also linked physical activity with changes in brain structure and function. Studies examining aerobic exercise have reported associations with reduced age-related brain-volume loss and neuroplasticity, the brain’s capacity to reorganize and adapt.
Some health commentators have gone further, arguing that exercise can help prevent or reverse neurological conditions including Alzheimer’s disease. Exercise is associated with better cardiovascular and cognitive health and may reduce several risk factors associated with dementia, but it has not been established as a treatment capable of reversing Alzheimer’s disease.
The new research specifically examined resistance exercise rather than relying exclusively on cardiovascular training.
Researchers found that participants did not need to lift at the highest intensity to demonstrate measurable differences. The moderate-intensity group used lighter loads and controlled movements, while the heavy-training group exercised with substantially greater resistance.
Both groups produced significant brain-age findings.
That could be particularly relevant for older adults or people beginning strength training later in life.
Early improvements in strength among beginners frequently result not only from changes within muscles but also from neurological adaptations that allow the brain and nervous system to recruit and coordinate muscles more efficiently.
Researchers said evidence does not support the idea that people reach an age at which they can no longer benefit from resistance training. Older adults can continue gaining strength when training is appropriately designed for their abilities and health conditions.
The report cited two to three strength-training sessions per week as a practical approach, with gradual increases in resistance over time.
Progressive overload — slowly increasing resistance, repetitions or training difficulty as a person becomes stronger — is a basic principle of resistance exercise.
Compound movements that engage multiple muscle groups can also provide an efficient way to build strength, although exercises can be modified depending on mobility, medical conditions and previous training experience.
The findings suggest consistency may be more important than attempting maximum-intensity lifting.
Resistance exercise can provide benefits beyond possible effects on the brain.
Strengthening muscles can improve physical function, mobility and the ability to perform routine activities. When exercises are performed safely through an appropriate range of motion, strength training can also contribute to balance and flexibility.
Those benefits become increasingly relevant with age because declining muscle strength and balance can raise the risk of falls.
Previous research involving women age 80 and older found that relatively simple strength and balance exercises were associated with a 40% reduction in falls.
The GeroScience study nevertheless has limitations.
Researchers studied older adults, meaning the magnitude of the brain-aging associations cannot automatically be applied to younger populations. Brain-age estimates also are biomarkers rather than direct measurements of whether an individual will develop dementia or another neurological condition.
The study did not establish that resistance training prevents Alzheimer’s disease, reverses cognitive impairment or extends life.
Additional research will be needed to determine how long the observed changes persist, whether greater changes develop with longer periods of training and how resistance exercise interacts with other factors including cardiovascular fitness, diet, sleep and underlying medical conditions.
The findings nevertheless add to a growing body of research associating regular physical activity with healthier aging.
For older adults interested in beginning resistance exercise, moderate training may offer many of the benefits observed in the study without requiring powerlifting-level intensity. People with significant medical conditions, mobility limitations or little previous exercise experience may benefit from discussing a new program with a health professional and increasing resistance gradually.
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