Some benefits from exercise like muscle strength start to diminish shortly after you take a break from working out, but that's not true with all benefits. New research from the University of Queensland in Australia found high-intensity interval exercise over a six-month period improves brain function in older adults for up to five years.
The study results published in the journal Aging and Disease showed the exercise was able to not only delay mental decline, but actually boost cognition.
The study is believed to be the first of its kind and involved various forms of exercise combined with brain scans.
"Six months of high-intensity interval training is enough to flick the switch," professor Perry Bartlett said. "In earlier pre-clinical work, we discovered exercise can activate stem cells and increase the production of neurons in the hippocampus, improving cognition.
"In this study, a large cohort of healthy 65–85-year-old volunteers joined a six-month exercise program, did biomarker and cognition testing and had high-resolution brain scans. We followed up with them five years after the program and incredibly they still had improved cognition, even if they hadn't kept up with the exercises."
Researchers measured the impact of three exercise intensities, low, medium and high. Low involved mainly balance and stretching. Medium was walking on a treadmill and high involved four cycles of running on a treadmill at near maximum exertion. Only the high-intensity exercise was able to induce the five-year improvement.
"On high-resolution MRI scans of that group, we saw structural and connectivity changes in the hippocampus, the area responsible for learning and memory," Dr. Daniel Blackmore said. "We also found blood biomarkers that changed in correlation to improvements in cognition.
"Our finding can inform exercise guidelines for older people and further research could assess different types of exercise that could be incorporated into aged care," Blackmore added. "We are now looking at the genetic factors that may regulate a person's response to exercise to see if we can establish who will and who will not respond to this intervention."