Scientific studies continue to show us how exercise can bring a range of cognitive benefits, from limiting the risk of Alzheimer's to giving an immediate boost to our learning capabilities. Researchers working in this area at the University of South Australia have turned their attention to neuroplasticity, finding two styles of workout in particular that give this key brain function the biggest boost.
Neuroplasticity refers to the brain's ability to rewire the neural connections as we go through life, whether that be in response to certain experiences, building memories, learning new skills or adapting to new environments. In this way, it is seen as critical to the development of a healthy brain from infancy all the way through to adulthood, and the authors of this new study set out to dig into how exercise can influence these vital pathways.
“We already know that engaging in regular aerobic exercise is good for the brain, improving memory, attention and learning,” says co-author Dr Ashleigh Smith. “However, we need to understand why it is so beneficial and what the best exercise, intensity and duration is.”
To find some answers to these questions, Smith and her team conducted experiments where 128 healthy participants between the ages of 18 and 65 were subjected to a variety of workout types. These ranged from low-intensity continuous exercises to high-intensity interval exercises, with the subject's heart rates varying between 50 to 90 percent of the maximum.
Using transcranial magnetic stimulation, the team measured the changes in the subjects' neuroplasticity before and after the exercises. The most profound changes, the researchers found, followed 20 minutes of high-intensity interval training or 25 minutes of continuous moderate aerobic exercise.
Furthermore, the team gathered some useful insights into the activity of the stress hormone cortisol during the different exercises. This appears to be a major factor in how mentally beneficial a particular exercise is, as high levels can block neuroplastic responses. The researchers found that mixing up the tempo through high-intensity interval training seemed to allow cortisol levels to return to normal, healthy levels.