Seniors' strength training helps cognition, Vancouver study finds
A once-weekly, hour-long program of "resistance training" to build strength resulted in a group of Vancouver women aged 65 to 75 seeing doctors less, taking fewer medications, and generally costing the health system less. The study found that such strength training outperformed twice-weekly balance and toning exercises.
A team of researchers from the Centre for Hip Health and Mobility at Vancouver Coastal Health, the University of B.C. and St. Paul's Hospital published their findings in the current issue of the Archives of Internal Medicine.
"I think our study shows that strength training needs to be better promoted," said lead author Teresa Liu-Ambrose. "The prevalence of seniors doing such exercise is quite low at the moment."
Cognitive decline among seniors is considered a serious challenge, given that demographic projections suggest that nearly a quarter of the B.C. population will be made up of seniors within 20 years.
About 30 per cent of seniors fall down each year, and about 4,000 suffer hip fractures. Such injuries raise the risk of death and cost the health care system tens of millions of dollars.
Seniors with cognitive impairment fall twice as much as their peers with no impairment. Liu-Ambrose said cognitive tests showed that about half of participants in the study had some mild cognitive impairment, which makes research on exercise training important as a protective strategy.
Their $250,000 Brain Power Study was a one-year followup to research conducted in 2007-2008 that included 155 women assigned randomly to one of three groups -- once-a-week resistance training classes, twice-weekly resistance training classes, or twice-weekly balance and toning training (featuring stretching, range of motion, core strength, balance and relaxation exercises). Classes were held at either a YMCA or at a Vancouver General Hospital site.
A year after these exercise programs ended, cognitive benefits endured, with the once-weekly strength training group showing the best outcomes in testing.
Joyce Mar, a study participant, said in an interview that she saw an advertisement for the research at a local YMCA, and decided to join because she was already exercising there.
"I think my strength improved a lot, and there was a detectable improvement in cognitive functions as well," said Mar, a retired public school teacher who was assigned to the twice-weekly resistance training classes.
The one-year followup study yielded some other intriguing findings. For example, individuals in the twice-weekly classes had more self-reported falls.
Also, researchers found that brain volumes shrunk slightly in subjects from both the resistance training groups, as evidenced by MRI scans. The volume reduction averaged just 0.35 per cent, and Liu-Ambrose said researchers are not yet sure what to make of the results.
Brain shrinkage is often associated with Alzheimer's disease, so if exercise is considered protective for the brain, then it is paradoxical that the brain would measure smaller for exercise participants.
"We've spoken about this with radiologists and neurologists, and we are now involved in further study. It's possible that weight training removes inflammation in the brain, and maybe that's why they appear smaller," she said.
Since the once-a-week resistance training group sustained cognitive benefits, fewer health care costs and fewer falls than the other two groups, coresearcher Jennifer David said: "This suggests that once-weekly resistance training is cost saving, and the right type of exercise for seniors to achieve maximum economic and health benefits."