It has long been known that physical exercise is not only beneficial for the body, but also for the brain. Numerous studies have shown that regular physical activity helps protect and preserve brain function throughout life.
A recent study found that one type of exercise may be more effective than others at improving brain health. Researchers found a link between high-intensity interval training (HIIT) sessions and improved memory and brain volume in older adults. These brain benefits even lasted up to five years after the study ended.
The researchers studied 194 adults aged 65 to 85 who showed no signs of cognitive decline. Participants were assigned to a program of low-intensity exercise, moderate-intensity exercise, or HIIT training for six months. Participants completed three workouts per week.
Low-intensity workouts included 30 minutes of stretching, balance, and relaxation exercises. Moderate-intensity workouts included 30 minutes of brisk walking on a treadmill.
The HIIT sessions were also performed on a treadmill, where participants completed a four-minute bout of intense exercise (at about 80–95% of their maximum heart rate) interspersed with three minutes of recovery. This session was repeated four times.
After six months of exercise, participants were asked to perform a task designed to test their memory. Participants in the HIIT group made fewer errors on this task than those in the low- and moderate-intensity groups.
Five years later, the participants performed this memory task again, and the HIIT groups still performed better than the other groups. The low- and medium-intensity groups remained the same and showed no improvement.
That’s not all. The researchers also found that the HIIT training group had less age-related brain volume decline. MRI scans of the brain showed that the right hippocampus, an area involved in memory, was better preserved in the HIIT group than in the other two groups. As with the memory improvements, these benefits were maintained even five years after the study ended.
Although the study’s findings are strong, it only looked at people who had no signs of cognitive decline, so it’s unclear whether similar results would be seen in people with cognitive impairment.
Additionally, the HIIT sessions were performed on treadmills, so it’s unclear whether the results would be the same if participants did other forms of exercise.
While previous animal research has shown a link between HIIT workouts and long-term brain benefits, this is one of the first studies to show a connection between the two in humans.
Benefits for the brain
There are three likely mechanisms that could explain why HIIT appears to be so beneficial for brain health.
The first is that HIIT improves cardiovascular fitness, which in turn improves how your brain functions.
Regular HIIT workouts improve cardiorespiratory fitness, which makes it easier for your heart to pump blood around your body. This in turn reduces the force on your arteries, which lowers blood pressure.
Maintaining healthy blood pressure is important for brain health because high blood pressure is associated with poor functioning of the brain’s small blood vessels. These changes are often accompanied by a reduction in brain volume in important brain regions, such as the hippocampus. This region is one of the first to be affected by Alzheimer’s disease.
The second reason HIIT may benefit brain health is that it reduces inflammation levels.
Constant and prolonged inflammation has been shown to have many negative effects on the brain. It is associated with poor brain metabolism and reduced brain tissue function. These changes can lead to cognitive dysfunction and have also been linked to the development of Parkinson’s disease and Alzheimer’s disease.
But HIIT workouts can reduce levels of a protein that contributes to chronic inflammation, called tumor necrosis factor alpha (TNF-α). The production of TNF-α is one of the first responses triggered by the body’s inflammatory process. High levels of TNF-α are associated with chronic inflammation.
The third reason why HIIT can be so beneficial for brain health is that it has a positive effect on brain cells (neurons). Healthy neurons are the brain’s information carriers. They are important for memory and communication between brain regions.
HIIT workouts increase levels of a protein called brain-derived neurotrophic factor (BDNF) in the blood. BDNF stimulates the growth and repair of neurons.
BDNF levels naturally decline with age. However, HIIT workouts can be a simple way to increase BDNF levels in your body and help improve your brain health.
HIIT workouts
It’s clear that HIIT is great for your brain health. But researchers aren’t sure what the perfect HIIT workout looks like. Researchers aren’t sure whether the length of the HIIT interval (doing 30 seconds of exercise versus four 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 research will need to explore.
Still, it’s clear from this study and others that HIIT is very beneficial. If you’re interested in trying HIIT, design a training program that alternates short bursts of intense exercise (close to your maximum effort) with short periods of recovery.
For example, a HIIT workout performed on an exercise bike might consist of a 5-minute warm-up followed by ten 30-second sprints, separated by 3 to 4 minutes of low-intensity exercise.
Regardless of the structure of the workout, HIIT offers many benefits to the brain and body.
This article is republished from The Conversation under a Creative Commons license. Read the original article.
