On the functional connectivity between heart, muscle, and frontal brain cortex during exercise fatigability

Area of Science:

• Neuroscience
• Exercise Physiology
• Biomedical Engineering

Background:

• Understanding the cortico-cardiac-muscular network is crucial for analyzing physiological responses to exercise.
• Muscle fatigability impacts functional connectivity within the human body's regulatory systems.

Purpose of the Study:

• To investigate changes in functional connectivity within the cortico-cardiac-muscular network during exercise-induced muscle fatigue.
• To compare these changes between active and sedentary individuals.

Main Methods:

• Recruited ten volunteers (active and sedentary) for cycling tests.
• Measured electromyography (EMG), electrocardiography (ECG), and electroencephalography (EEG) signals.
• Analyzed functional connectivity using partial directed coherence at the dominant brain rhythm.

Main Results:

• Sedentary group: significant decrease in overall functional connectivity.
• Active group: increased left-frontal connectivity, suggesting positive emotional states.
• Active group: enhanced self-regulation in heart and muscle; sedentary group: reduced self-regulation and heart-to-muscle connectivity.

Conclusions:

• Exercise-induced muscle fatigue differentially affects functional connectivity in active versus sedentary individuals.
• Active individuals demonstrate improved network regulation and potential positive emotional responses.
• Sedentary individuals exhibit diminished self-regulatory capacity, prioritizing vital functions over exercise demands.