Physical activity is known to be good for health, but can as little as a single exercise session have positive effects on the brain? Medical News reports on US research showing that acute exercise improves mood and focus and reduces stress.
The study investigates the effect of acute exercise – defined as a single session of physical activity – on human mood and cognition. The research was carried out by scientists at the Centre for Neural Science at New York University (NYU) in New York City.
As the authors of the study explain, although research has already been carried out on the effects of acute exercise on cognition and mood, fewer studies have focused on the neuro-biological underpinnings of these effects.
Focusing on the effects of a single session of exercise is important because it helps researchers to gain a better understanding of how sustained exercise over a longer period of time may add up to create long-term changes in the brain.
Besides summing up the existing findings, the review also focuses on the cognitive and behavioral changes that take place in both humans and rodents after an intense single session of exercise. The review also points out the strengths and limitations of the current literature, identifying directions for future research.
Lead investigator Dr Wendy A Suzuki, a professor of neural science and psychology in the Centre for Neural Science at NYU, explains the context of the new study: “Exercise interventions are currently being used to help address everything from cognitive impairments in normal aging […] to motor deficits in Parkinson’s disease and mood states in depression. Our review highlights the neural mechanisms and pathways by which exercise might produce these clinically relevant effects.”
The review mainly examines the effects of a single session of aerobic exercise, lasting approximately 1 hour. Suzuki and her team reviewed information available from brain imaging and electro-physiological studies. The existing research shows that physical activity may protect against neuro-degeneration and other aging-related forms of cognitive impairment. The authors report several key findings.
Firstly, across all of the studies reviewed, acute exercise consistently resulted in three main effects: better executive function (the mental processes that help us to plan, focus, and multitask); better mood; and lower stress levels.
Additionally, the studies revealed that acute exercise activates several extended brain areas. “One of the most dramatic effects,” the authors write, “is the change in neuro-chemical levels.”
This includes neurotransmitters; exercise was shown to increase levels of dopamine, epinephrine, norepinephrine, and serotonin. Dopamine helps the brain to learn and is involved in the rewarding circuits.
A certain level of physical activity seems to be able to increase serotonin, which relieves anxiety and depression, in both humans and rodents. Furthermore, a single exercise session seemed to increase levels of so-called neuro-modulators. These include endogenous opioids and endocannabinoids – that is, “feel good” chemical substances that are naturally produced by the brain when we exercise. These account for the runner’s high effect and exercise-induced states of euphoria.
Endogenous opioids are involved in the brain’s response to pain and stress, as well as in self-control and reward.
The report says one of the most challenging areas for future research is understanding the relationship between the post-exercise neuro-chemical changes found in rodents, and the behavioral ones found in humans. This is due to a “gap” in the current literature signaled by the researchers, where an insufficient number of studies have investigated the cognitive and behavioral effects of acute exercise in rodents.
“The studies presented in this review clearly demonstrate that acute exercise has profound effects on brain chemistry and physiology, which has important implications for cognitive enhancements in healthy populations and symptom remediation in clinical populations.”
A significant body of work has investigated the effects of acute exercise, defined as a single bout of physical activity, on mood and cognitive functions in humans. Several excellent recent reviews have summarized these findings; however, the neurobiological basis of these results has received less attention. In this review, we will first briefly summarize the cognitive and behavioral changes that occur with acute exercise in humans. We will then review the results from both human and animal model studies documenting the wide range of neurophysiological and neurochemical alterations that occur after a single bout of exercise. Finally, we will discuss the strengths, weaknesses, and missing elements in the current literature, as well as offer an acute exercise standardization protocol and provide possible goals for future research.
Basso, Julia C, Suzuki, Wendy, A