High-intensity interval training (HIIT) is one of the best tools in the toolbox for getting an efficient workout. You already knew that, right? Plus, it offers substantial health benefits for heart and brain health. The intense nature of HIIT triggers more beneficial adaptations than moderate-intensity workouts, based on some studies.
But here’s what you might not know. The effects of HIIT training may last longer than you think. According to a groundbreaking study from the University of Queensland, high-intensity interval training (HIIT) boosts brain function in older adults. This is the part that will make you do a double-take. The brain function benefits you get from HIIT workouts for six months may last up to five years. Talk about a good return on your time! But how did scientists discover this?
The Long-Lasting Benefits of High-Intensity Exercise
Researchers were interested in how long the benefits of high-intensity training last. To explore further, they organized a study to clarify this burning issue. For the research, they recruited older adults to take part in a high-intensity interval training program for six months. The participants were between the ages of 65 and 85 and had no significant health problems prior to the study.
The researchers looked at the impact of three exercise intensities over the course of the study:
- Low intensity: Focusing on motor function, balance, and stretching.
- Medium-intensity: Brisk walking on a treadmill
- High-intensity: Near-maximum exertion running on a treadmill.
Their findings? Participants who did the high-intensity exercise enjoyed improvements in brain health that lasted 5 years. Importantly, only the high-intensity group experienced this benefit.
How High-Intensity Exercise Affects Markers of Cognitive Health
To see how each type of exercise affected brain function, the subjects in the study underwent high-resolution MRI scans. What the scans showed was a boost in connectivity between portions of the brain involved with cognition, particularly learning and memory. Again, the changes only occurred in those who worked out at a high intensity.
Plus, researchers checked their blood for markers suggestive of better cognitive function and found improvements in those too.
How Does High-Intensity Exercise Boost Cognitive Health?
Previous studies show ways in which intense exercise enhances brain function. These include:
Changes in Brain Structure
As the researchers found in this study, intense exercise can trigger structural changes in the brain, in an area called the hippocampus. Think of your hippocampus as part of your learning and memory center. HIIT boosts connectivity between various parts of the hippocampus, so you process information and learn more efficiently. For example, research shows improvements in spatial memory with intense exercise.
Increased BDNF Levels
There’s another way exercise boosts brain function. It does so by boosting the amount of BDND (brain-derived neurotrophic factor) that the hippocampus’s dentate gyrus releases. When BDNF, often referred to as fertilizer for the brain rises, your brain functions more efficiently and you perform better mentally.
Enhanced Cognitive Flexibility:
HIIT workouts also have an impact on cognitive flexibility, which is your ability to shuffle your thoughts between different ideas. When you boost your mental agility, you can manage new situations better and solve unfamiliar problems more. Let’s say you’re working on a puzzle or trying to figure out a tricky problem. Being flexible helps you find the solution quicker by letting you switch up your thinking more. It also makes you a faster problem solver. Plus, it gives you a greater ability to tap into new information and consider new approaches.
Improved Executive Function:
Research shows that high-intensity exercise improves executive function more than moderate-intensity exercise does. Executive function is the portion of your working memory that helps you retain information short-term and use it to solve problems. It also helps you organize, plan, and go through the steps you need to achieve goals.
With enhanced executive function you can better manage your time and resources. It also helps you focus your attention, switch between tasks, plan, remember important info, and keep your impulses in check. You need these skills to finish tasks and reach your goals. Otherwise, you’ll be distracted by everything in your environment and be so disorganized that you never get anything done.
Executive function is your brain’s control center steering your actions and letting you make tough choices. When your executive function is strong, it also helps you tune out things that might pull you away from what you want to do and what you’ve planned. For example, you might have the urge to go to the park when you’re scheduled to work. It’s your brain’s executive function that keeps you from skipping out on work to have fun.
Increased Cerebral Blood Flow:
When you start working out, your breathing speeds up. This happens to supply more oxygen to your body parts, which need it for metabolism. Your blood flow increases, and your hippocampus gets more oxygen. This boost in oxygen and nutrients to this area helps improve brain function.
Possible Brain-Protecting Effects:
The brain benefits of HIIT might help fight age-related mental decline. Although studies are still exploring the possibility that intense exercise lowers the risk of Alzheimer’s disease, it likely does reduce the risk of vascular dementia, the second most common form. This matters a lot because many older people face cognitive decline.
Improved Cardiorespiratory Fitness:
HIIT leads to significant improvements in cardiorespiratory fitness, which is associated with better cognitive function and brain health in older adults.
Getting the Benefits of HIIT Training
To get the full benefits of HIIT training, aim for a target heart rate of 85% to 95% of your maximum heart rate during the active intervals. Your rest intervals should be long enough to allow your heart rate to partially recover. If you’re starting out, begin with short periods of high-intensity exercise alternating with longer recovery periods.
As you build up greater cardiovascular fitness, expand the length of the active intervals or shorten the recovery intervals. The beauty of HIIT training (other than the benefits) is you can use a HIIT structure for any type of exercise – running, cycling, rowing, or even bodyweight exercises. Make sure your doctor clears you to do HIIT training.
Conclusion
Although other research shows intense exercise offers a brain boost, this study shows how long-lasting the effects can be. In this case, six months of HIIT training in older people lead to improvements in brain function that lasted five years. Any exercise is good for you, but boosting your heart rate more with more intense exercise seems to offer the greatest long-term boost to brain health in older people.
So, don’t be afraid to pick up the pace and do something smart for your brain. And don’t forget you’re boosting the health of your heart too.
References:
- “UQ Research Reveals Exercise Brain Boost Can Last for Years.” 2024. UQ News. 2024. https://www.uq.edu.au/news/article/2024/07/uq-research-reveals-exercise-brain-boost-can-last-years.
- “Exercise Brain Boost Can Last for Years.” 2024. ScienceDaily. 2024. https://www.sciencedaily.com/releases/2024/07/240710002013.htm.
- Mekari S, Neyedli HF, Fraser S, O’Brien MW, Martins R, Evans K, Earle M, Aucoin R, Chiekwe J, Hollohan Q, Kimmerly DS, Dupuy O. High-Intensity Interval Training Improves Cognitive Flexibility in Older Adults. Brain Sci. 2020 Oct 29;10(11):796. doi: 10.3390/brainsci10110796. PMID: 33137993; PMCID: PMC7693870.
- Erickson KI, Voss MW, Prakash RS, Basak C, Szabo A, Chaddock L, Kim JS, Heo S, Alves H, White SM, Wojcicki TR, Mailey E, Vieira VJ, Martin SA, Pence BD, Woods JA, McAuley E, Kramer AF. Exercise training increases size of hippocampus and improves memory. Proc Natl Acad Sci U S A. 2011 Feb 15;108(7):3017-22. doi: 10.1073/pnas.1015950108. Epub 2011 Jan 31. PMID: 21282661; PMCID: PMC3041121.
- Mekari S., Neyedli H.F., Fraser S., O’Brien M.W., Martins R., Evans K., Earle M., Aucoin R., Chiekwe J., Hollohan Q., et al. High-Intensity Interval Training Improves Cognitive Flexibility in Older Adults. Brain Sci. 2020;10:796.
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