A study by Australia researchers has found that high-intensity interval exercise boosted cognition in healthy older adults for up to five years.
The study was led by Emeritus Professor Perry Bartlett and Dr Daniel Blackmore from UQ’s Queensland Brain Institute who said it was the first controlled study of its kind to show exercise can boost cognition in healthy older adults — not just delay cognitive decline.
“Six months of high-intensity interval training is enough to flick the switch, physical exercise was a promising non-invasive approach to ameliorate age-associated hippocampal cognitive deficits,” Professor 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.”
The hippocampus is responsible for the consolidation of spatial information into memories and is particularly susceptible to age, with reports of age-dependent decreased hippocampal volume and connectivity.
During the study, the researchers assessed the impact of three exercise intensities 36-45 min exercise sessions per week over a 6-month period for a total of 72 exercise sessions; all training sessions were supervised by qualified exercise physiologists and were conducted in a small group setting:
- Low (LIT) – motor function, balance and stretching
- Medium (MIT) – brisk walking on a treadmill
- High (HIIT) – four cycles running on a treadmill at near maximum exertion
Dr Blackmore said only the high-intensity interval exercise led to cognitive improvement that was retained for up to five years.
“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 had not kept up with the exercises,” he said.
“In contrast to previous studies, we found little evidence that exercise affected other cognitive domains including working memory, visual working memory and emotional recognition.
“Both growth hormone and β-hydroxybutyrate showed consistent post-exercise increases relative to pre-exercise levels for all groups while cortisol, prolactin and BDNF showed post-exercise responses that were dependent on exercise intensity.”
The study found that cumulative ∆GH increased for all groups during the exercise intervention, with the largest increase also occurring in the HIIT group. This value was significantly higher than that of either the LIT or MIT group at the completion of the intervention.
“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,” Dr Blackmore said.
“Ageing dementia, including Alzheimer’s disease, is a significant health concern, with more than 130 million people worldwide predicted to suffer from the condition by 2050. Delaying the onset of dementia by five years would result in a decreased prevalence of 41% by 2050.”