An Australian study has shown for the first time how doing strength exercises slows, or even halts, degeneration in the brain’s hippocampus. Professor Michael Valenzuela, of the Brain and Mind Research Centre at the University of Sydney, said the evidence was so clear that, “resistance exercise needs to become a standard part of dementia risk-reduction strategies.”

His team studied 100 adults who were experiencing mild cognitive impairment (MCI), a condition where there is a decline in memory and other thinking skills. MCI is often thought to be a precursor to dementia. 

The 100 participants in Australia were split into four groups. One was given computerised brain training, another strength training, another a combination of the two, and there was a control group. The group doing strength exercises did 90 minutes of supervised strength training, using dumbbells, weights or machines, each week for six months.

“They did the exercises for 45 minutes, twice a week, for six months, and then we waited for 12 months and that’s when we saw these really strong effects,” said Professor Valenzuela. He said it was the first time that any medical or lifestyle intervention had been shown to slow or halt degeneration in the brain over such a period.

“In the control group, those sub- parts of the hippocampus were shrinking at an expected level of around 3 to 4%. In those doing weight training, we saw much less, 1 to 2% and in some areas none at all.” The people in the group doing strength exercises had far better cognitive outcomes.

He was surprised by how clear the results were, saying, “There was no grey zone about these results. There was such a clear difference in terms of brain anatomy. What we saw was a difference in terms of decline. These are not just structural changes, which are interesting for their own sake. They have a functional consequence.”

We would all like to have a healthy brain in old age, and research tells us that the best way to do this is to begin looking after it in middle age. Women who experience chronic stress in middle age are more likely to develop dementia when they are older according to some studies. Other studies show that regular exercise reduces cortisol levels, which in turn lowers stress. In addition, experts agree that what’s good for your heart is good for your brain.

Strength training is the only type of exercise that can substantially slow and even reverse the declines in muscle mass, bone density, and strength that were once considered inevitable consequences of aging, according to VeryWell, a partner of The Cleveland Clinic, New York.  The organisation’s website gives information on how to exercise safely.