THINK you're past lifting weights? If so, you had better think again... it could be good for your brain.
Researchers at the University of Sydney have found that six months of strength training - lifting weights - can help protect brain areas especially vulnerable to Alzheimer's disease up to one year later.
The clinical trial was conducted for older people at high risk of Alzheimer's disease due to mild cognitive impairment - a decline in memory and other thinking skills despite generally intact daily living skills.
People with mild cognitive impairment are at a one-in-10 risk of developing dementia within a year.
Participants were randomly allocated to do computerised brain training, strength training, and combined computer and strength training, which they did for six months, followed by their usual activity for 12 months.
The long-term study found that strength training led to overall benefits to cognitive performance - benefits linked to protection from degeneration in specific subregions of the hippocampus (a complex structure in the brain with a major role in learning and memory).
The hippocampus subregions targeted by the strength training were those especially vulnerable to Alzheimer's disease.
Where no strength training was done, hippocampal subregions shrunk by 3-4 per cent over the 18 months. Those undergoing strength training saw only 1-2 per cent reductions and, in some areas, none at all.
Strength training is physical exercise that requires repetitive contraction of the major muscle groups against an opposing force, typically a free weight or using gym equipment.
To arrive at their conclusions, the team conducted MRI brain scans of the participants three times over 18 months and used some of the latest advances in imge analysis to quantify changes to subregions within the hippocampus.
Senior author of the study, Professor Michael Valenzuela, believes the findings should change the dementia prevention message.
"This is the first time any intervention, medical or lifestyle, has been able to slow and even halt degeneration in brain areas particularly vulnerable to Alzheimer's disease over such a long time," he said.
"Given this was also linked to protection from cognitive decline, the message is clear: resistance exercise needs to become a standard part of dementia risk-reduction strategies."
Professor Valenzuela is one of the leaders of the Australian Maintain your Brain online trial that will test if a tailored program of lifestyle modification, including resistance exercise, can prevent cognitive loss in a group of 6000-plus older people.
The study findings have been published in the specialist journal Neuroimage: Clinical.
