Mental Stress Can Lead to Physical Fatigue

New research addresses a topic that may resonate with many as investigators study the ways in which stress and mental frustration can leave us physically tired and worn out.

In the study, Ranjana Mehta, Ph.D., an assistant professor at the Texas A&M Health Science Center School of Public Health, evaluated this interaction between physical and mental fatigue and brain behavior.

Typically, endurance and fatigue have been examined solely from a physical perspective, focused primarily on the body and muscles used to complete a specific task.

However, the brain is just like any other biological tissue; it can be overused and can suffer from fatigue.

“Existing examinations of physical and mental fatigue has been limited to evaluating cardiovascular, muscular and biomechanical changes,” said Mehta.

“The purpose of this study was to use simultaneous monitoring of brain and muscle function to examine the impact on the prefrontal cortex (PFC) while comparing the changes in brain behavior with traditional measures of fatigue.”

According to Mehta, study findings show that there were lower blood oxygen levels in the PFC following combined physical and mental fatigue compared to that of just physical fatigue conditions.

Therefore, significant brain use when participating in highly cognitive tasks, can cause brain resources to be divided which may accelerate the development of physical fatigue.

Experts believe it is critical that researchers consider the brain as well as the body when examining fatigue development and its impact on the body.

This is best accomplished by interdisciplinary work that combines neurocognitive principles with physiological and biomechanical outcomes can provide us with a comprehensive understanding of what is happening to the body when we perform our daily activities.

“Not a lot of people see the value in looking at both the brain and the body together,” said Mehta. “However, no one does purely physical or mental work; they always do both.”

This study appears online in Human Factors: The Journal of the Human Factors and Ergonomics Society.

Source: Texas A&M