(MCI), new research from the largest study of its kind suggests. Topline results from the EXERT trial showed patients with MCI who participated regularly in either aerobic exercise or stretching/balance/range-of-motion exercises maintained stable global cognitive function over 12 months of follow-up – with no differences between the two types of exercise.
“We’re excited about these findings, because these types of exercises that we’re seeing can protect against cognitive decline are accessible to everyone and therefore scalable to the public,” study investigator Laura Baker, PhD, Wake Forest University School of Medicine, Winston-Salem, N.C., said at a press briefing.
The topline results were presented at the 2022 Alzheimer’s Association International Conference.
No decline
The 18-month EXERT trial was designed to be the definitive study to answer the question about whether exercise can slow cognitive decline in older adults with amnestic MCI, Dr. Baker reported. Investigators enrolled 296 sedentary men and women with MCI (mean age, about 75 years). All were randomly allocated to either an aerobic exercise group (maintaining a heart rate at about 70%-85%) or a stretching and balance group (maintaining heart rate less than 35%).
Both groups exercised four times per week for about 30-40 minutes. In the first 12 months they were supervised by a trainer at the YMCA and then they exercised independently for the final 6 months.
Participants were assessed at baseline and every 6 months. The primary endpoint was change from baseline on the ADAS-Cog-Exec, a validated measure of global cognitive function, at the end of the 12 months of supervised exercise.
During the first 12 months, participants completed over 31,000 sessions of exercise, which is “quite impressive,” Dr. Baker said.
Over the first 12 months, neither the aerobic group nor the stretch/balance group showed a decline on the ADAS-Cog-Exec.
“We saw no group differences, and importantly, no decline after 12 months,” Dr. Baker reported.
Supported exercise is ‘crucial’
To help “make sense” of these findings, Dr. Baker noted that 12-month changes in the ADAS-Cog-Exec for the EXERT intervention groups were also compared with a “usual care” cohort of adults matched for age, sex, education, baseline cognitive status, and APOE4 genotype.
In this “apples-to-apples” comparison, the usual care cohort showed the expected decline or worsening of cognitive function over 12 months on the ADAS-Cog-Exec, but the EXERT exercise groups did not.
Dr. Baker noted that both exercise groups received equal amounts of weekly socialization, which may have contributed to the apparent protective effects on the brain.
A greater volume of exercise in EXERT, compared with other trials, may also be a factor. Each individual participant in EXERT completed more than 100 hours of exercise.
“The take-home message is that an increased amount of either low-intensity or high-intensity exercise for 120-150 minutes per week for 12 months may slow cognitive decline in sedentary older adults with MCI,” Dr. Baker said.
“What’s critical is that this regular exercise must be supported in these older [patients] with MCI. It must be supervised. There has to be some social component,” she added.
In her view, 120 minutes of regular supported exercise for sedentary individuals with MCI “needs to be part of the recommendation for risk reduction.”