Presentation
PFC and Motor Activation Under Stress During Fatiguing Exercise in Young Adults
SessionLBR1: Late-Breaking Results
DescriptionFatiguing exercise of the upper extremity muscles can be affected by acute cognitive stress. The prefrontal cortex, which influences the motor cortex to regulate exercise and fatigue, is particularly affected. However, the underlying neural mechanisms through which stress affects neuromuscular performance in both men and women remain largely unexplored. This study measured activation in prefrontal cortex and motor areas under acute cognitive stress for both men and women. Twenty-five young adults (12 males and 13 females) performed intermittent elbow flexion at 30% of their maximum strength until voluntary fatigue. Participants underwent two sessions: a control session where participants performed a fatiguing elbow flexion task of the right arm, and a stress session that included a mental math task concurrently applied with the fatiguing exercise. Functional near-infrared spectroscopy (fNIRS) measured activation in the prefrontal and motor areas of the brain. Results indicated that despite lower fatigability exhibited by longer endurance times, stress impaired motor performance for both sexes. Additionally, overall brain activation for elbow flexion was lower under stress compared to the control condition, likely due to the cortical resources being divided between the mental and physical tasks. There was also a notable increase in activation with fatigue across all brain regions. These findings suggest that due to the distraction effect of the mental math task, participants were able to delay fatigue under stress. In conclusion, this study was able to demonstrate the important role of the cortical brain in neuromuscular fatigue, and how it may be affected by cognitive perturbations.
Event Type
Late Breaking Results
TimeTuesday, September 10th3:10pm - 3:20pm MST
LocationFLW Salon I