Just two strength-training sessions a week helped reverse memory decline and protect brain areas linked to Alzheimer’s, according to groundbreaking Brazilian research

A six-month Brazilian study has revealed that regular weight training may offer powerful protection against dementia, even for older adults already showing signs of cognitive decline. Conducted by researchers at the State University of Campinas (UNICAMP), the study involved 44 participants with mild cognitive impairment (MCI)—a condition seen as a precursor to Alzheimer’s.

Over the course of the study, one-half of the group participated in twice-weekly resistance training sessions. The results were dramatic: not only did these individuals show improvements in verbal memory, but MRI scans also revealed better-preserved brain regions typically affected by Alzheimer’s, including the hippocampus and precuneus. Meanwhile, the control group who didn’t exercise saw a decline in those same areas.

Dr Isadora Ribeiro, lead author of the study, described the outcome as “something to be hopeful about,” noting that even in high-risk individuals, strength training had a protective effect on memory and brain structure. “All the individuals in the bodybuilding group showed improvements in memory and brain anatomy,” she said. In five cases, participants even improved enough that they no longer met the diagnostic criteria for MCI by the study’s end.

Professor Marcio Balthazar, who supervised the research, added that this kind of intervention was significantly cheaper and simpler than the anti-amyloid drugs recently approved in the US, which can cost over £23,000 a year.

The study, published in the journal GeroScience, is the first of its kind to document the effects of strength training on white matter integrity in people with MCI. It also measured biomarkers like irisin and BDNF—proteins released during muscle activity that support neuron health, reduce inflammation and enhance brain plasticity.

“Any physical exercise increases the chemical messengers involved in brain growth,” said Prof Balthazar. “This helps slow the neurodegenerative processes that contribute to Alzheimer’s.”

Diet Also Plays a Role

Experts suggest pairing weight training with the MIND diet—a brain-focused combination of the Mediterranean and DASH diets. It emphasises leafy greens, berries, whole grains, beans, fish, poultry, olive oil, and nuts while limiting red meat, butter, cheese, sweets, and fast food. This approach is already shown to reduce cognitive decline.

A Low-Cost, High-Impact Lifestyle Change

While drug-based treatments for dementia remain costly and controversial, lifestyle-based interventions like weight training offer a practical and effective solution. “We believe it’s a set of anti-inflammatory and neuroprotective factors that lead to these changes,” Dr Ribeiro explained.

Researchers are continuing to analyse blood samples from the study to better understand how weight training alters brain biochemistry. There’s hope that longer training periods—such as three years—might even delay or reverse dementia progression.

With dementia cases on the rise worldwide, this study offers a hopeful message: getting older doesn’t mean surrendering your mental sharpness. A couple of trips to the gym each week might make all the difference.