We've long known that exercise is good for your brain as well as your body, and numerous studies have shown that regular exercise helps protect and maintain brain function throughout your life.
A recent study has revealed that certain types of training may be more effective than others when it comes to boosting brain health. Researchers found a link between high-intensity interval training (HIIT) training and improved memory and brain capacity in older adults. And these brain benefits persisted for up to five years after the study was completed.
Researchers studied 194 adults aged 65 to 85 who had no signs of cognitive decline. Participants were assigned to either a low-intensity, moderate-intensity, or HIIT training program, working out three times a week for six months.
Low-intensity training consisted of 30 minutes of stretching, balance, and relaxation exercises. Moderate-intensity training consisted of 30 minutes of brisk walking on a treadmill.
The HIIT sessions were also conducted on a treadmill, with participants doing four minutes of intense exercise (approximately 80-95% of their maximum heart rate) separated by three minutes of recovery, repeated four times.
After six months of exercising, the participants were given a task to test their memory. Participants in the HIIT group made fewer errors in the task compared to participants in the low- and moderate-intensity groups.
When participants were given the memory task again five years later, those in the HIIT group still outperformed the other groups. The scores of the low- and moderate-intensity groups remained the same and showed no improvement.
And that's not all: The researchers also found that the HIIT training group experienced less age-related loss of brain volume. Brain MRI scans showed that the right hippocampus, an area associated with memory, was better preserved in the HIIT group than the other two groups. As with the memory improvements, these benefits persisted even five years after the study ended.
Although the study’s conclusions are strong, it only included people who had no signs of cognitive decline, so it’s unclear whether similar results would be seen in people with cognitive impairments.
Additionally, the HIIT sessions were conducted on a treadmill, so it's unclear whether the same results would have been achieved if participants had performed other forms of exercise.
Previous studies in animals have linked HIIT training to long-term brain benefits, but this is one of the first to show a link between the two in humans.
Brain benefits
There are three possible mechanisms that could explain why HIIT is so beneficial for brain health.
Firstly, HIIT improves cardiovascular fitness, which also benefits brain function.
Regular HIIT training improves your cardiovascular fitness and makes it easier for your heart to pump blood around your body, which in turn reduces force on your arteries and lowers your blood pressure.
Maintaining healthy blood pressure is important for brain health, as high blood pressure is associated with impaired functioning of small blood vessels in the brain. These changes are often accompanied by volume loss in key brain regions such as the hippocampus, one of the first areas affected by Alzheimer's disease.
The second reason HIIT may be beneficial for brain health is that it reduces inflammation levels.
Long-term, ongoing inflammation has been shown to have many adverse effects on the brain. Inflammation is associated with decreased brain metabolism and impaired brain tissue function. These changes can lead to cognitive impairment and are also associated with the development of Parkinson's and Alzheimer's diseases.
However, HIIT training can reduce levels of tumor necrosis factor alpha (TNF-α), a protein that contributes to chronic inflammation. The production of TNF-α is one of the first responses triggered by the body's inflammatory process. High TNF-α levels lead to chronic inflammation.
The third reason HIIT is thought to be so beneficial for brain health is because of the positive effects it has on brain cells (neurons). Healthy neurons are the brain's messengers – they're important for memory and communication between brain regions.
HIIT training increases levels of a protein in the blood called brain-derived neurotrophic factor (BDNF), which stimulates the growth and repair of neurons.
BDNF levels naturally decline with age, but HIIT training could be a simple way to boost BDNF levels in the body and improve brain health.
HIIT Training
It's clear that HIIT is good for your brain health. But one thing researchers aren't sure about is what the perfect HIIT training plan looks like. Researchers aren't sure whether the length of the HIIT intervals (30 seconds vs. 4 minutes) or the number of intervals performed in each session is more important when it comes to brain health benefits. This is something that future studies will need to explore.
Still, it's clear from this study and others that HIIT can be extremely beneficial. If you want to give HIIT a try, create a training plan that alternates short periods of intense exercise (close to maximum effort) with short recovery periods.
For example, a HIIT workout on a stationary bike might consist of a five-minute warm-up followed by ten 30-second sprints with three to four minutes of low-intensity effort in between.
Regardless of the workout structure, HIIT offers many benefits to both the brain and body.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
