Resistance Training Improves Cognitive Function in Senior Women, Researchers Find
Resistance training in senior women may improve their higher brain functions. A 12-month, Vancouver-based experiment on women ages 65 to 75 shows that resistance training, or anaerobic exercise, doesn’t just increase bone mass and maintain muscle mass and strength—it also increases selective attention and the ability to resolve conflicts. These capacities are considered one aspect of the higher mental abilities called executive function.
Resistance training has been less studied in relation to executive function. “Most studies today have focused primarily on aerobic training,” says Dr. Teresa Liu-Ambrose, who led the research out of the Centre for Hip Health and Mobility, which is affiliated with the University of British Columbia and the Vancouver Coastal Health Research Institute. Liu-Ambrose says her experiment is the first to show a relationship between selective attention and conflict resolution, and walking speed. The greater a person’s test score, the faster their gait tended to be. Recent research has shown that walking speed is a strong indicator of general well-being and probability of future mortality.
The experiment was published in the January 25 issue of Archives of Internal Medicine. Researchers randomly assigned participants to one of three year-long exercise regimens. One group of women, the “balance and tone” group, exercised aerobically twice a week. The two other groups exercised anaerobically with resistance training. One trained once a week, and the other twice a week. Liu-Ambrose, who is also an assistant professor at UBC, did not include a no-exercise group in the experiment, so executive function scores of the exercise groups could not be compared with scores for senior women who did not exercise.
The researchers tested three different aspects of participants’ executive function: selective attention and conflict resolution, set shifting (the ability to modify behaviour in a changing situation), and working memory (the ability to mentally manipulate information). Then they compared how much the groups had improved by the end of the year, on average, on each of these abilities.
The resistance-trained women significantly improved their selective attention and conflict resolution, whereas the aerobics-trained women’s scores on that measure were the same at the end of the year as the beginning. This increase in abilities for the resistance training groups is particularly surprising, says Liu-Ambrose, because executive function is known to have the opposite trend for adults— it declines over time. Only resistance training caused an improvement in this aspect of executive function.
Meanwhile, set shifting and working memory scores improved over all three exercise groups. Both aerobic exercise and resistance training boosted these types of executive function.
Since social interaction also strongly benefits executive function, the researchers designed the experiment so all three groups socialized equally.
Liu-Ambrose thinks a difference in the learning required may have caused the differential improvement in the scores. The resistance training used may have required the participants to learn more, necessitating the brain to improve executive function.
The aerobic group performed stretching, range-of-motion, core strength, balance, and relaxation exercises. The resistance training groups used the Keiser system, a series of weight training machines including leg press, hamstring curl, lat pulldown, seated rowing, calf raising, biceps and triceps exercises. They also did free-form exercises like squats and lunges.
The researchers increased the difficulty of resistance training gradually, according to each participant’s needs. They added weights and more advanced techniques as individuals learned to maintain proper form. “The added loading [of resistance training] requires a lot more learning,” says Liu-Ambrose. “There are a lot of mental calculations. Those types of requirements don’t exist as much in the aerobic training program.”
The findings hint that executive function might be improved by any type of exercise that requires learning, but more research is needed. Liu-Ambrose and her colleagues are currently working on another study comparing the effects of aerobic and resistance training.
For now, she hopes her findings encourage older women to use resistance training. “It’s an underutilized mode of training for older adults, especially for senior women,” she says. “It’s a good alternative of exercise for those that have less mobility but wish to do something that may be beneficial for them.”