Exercise may improve not only physical fitness but also mental fitness—and a recent imaging study could provide evidence as to why.

The study, from UC Davis Health System, suggests that intense exercise helps increase levels of two common neurotransmitters—glutamate and gamma-aminobutyric acid, or GABA—that are reportedly responsible for chemical messaging within the brain.

Depression and other neuropsychiatric disorders may be linked with deficiencies in neurotransmitters, according to a media release from University of California – Davis Health System.

In the study, published recently in The Journal of Neuroscience, researchers conducted MRI exams on 38 healthy volunteers before and after exercising on a stationary bicycle to reach around 85% of their maximum heart rate.

To measure glutamate and GABA, the researchers conducted a series of imaging studies using a powerful 3-tesla MRI to detect nuclear magnetic resonance spectra, which can identify several compounds based on the magnetic behavior of hydrogen atoms in molecules.

The researchers measured GABA and glutamate levels in two different parts of the brain immediately before and after three vigorous exercise sessions lasting between eight and 20 minutes, and made similar measurements for a control group that did not exercise. Glutamate or GABA levels increased in the participants who exercised, but not among the non-exercisers. Significant increases were found in the visual cortex, which processes visual information, and the anterior cingulate cortex, which helps regulate heart rate, some cognitive functions, and emotion. While these gains trailed off over time, there was some evidence of longer-lasting effects, the release explains.

“There was a correlation between the resting levels of glutamate in the brain and how much people exercised during the preceding week,” says the study’s lead author, Richard Maddock, professor in the Department of Psychiatry and Behavioral Sciences, in the release. “It’s preliminary information, but it’s very encouraging.”

Per the release, the findings may point to the possibility that exercise could be as an alternative therapy for depression.

“We are offering another view on why regular physical activity may be important to prevent or treat depression,” Maddock states in the release. “Not every depressed person who exercises will improve, but many will. It’s possible that we can help identify the patients who would most benefit from an exercise prescription.”

[Source(s): University of California – Davis Health System, Science Daily]