Exercise-induced changes in high-γ cortical functional connectivity and short-interval intracortical inhibition, 2025, Conti et al

Exercise-induced changes in high-γ cortical functional connectivity and short-interval intracortical inhibition

Matteo Conti, Federico Carparelli, Roberta Bovenzi, Valerio Ferrari, Battista Di Gioia, Nicola Biagio Mercuri, Alessandro Stefani, Maria Giuseppina Palmieri

Highlights
• Central fatigue is more challenging to study than the peripheral one, requiring more neurophysiological techniques.
• Ten healthy volunteers underwent HD-EEG and pp-TMS before and 24–72 h after a 3 km high-intensity run.
• After 24 h, a significant hyperconnectivity in the high-γ band and a consistent hyperexcitability in left M1 were observed.

Objective
To analyze exercise-induced changes in functional connectivity (FC) using high-density EEG (HD-EEG) and primary motor cortex excitability via paired-pulse TMS (pp-TMS).

Methods
Ten healthy volunteers performed a 3 km high-intensity run. Neurophysiological assessments were conducted at baseline (T0), 24 h (T1), and 72 h (T2) post-exercise. FC was measured using HD-EEG, and primary motor cortex excitability was assessed with pp-TMS to measure short-interval intracortical inhibition (SICI) and facilitation (ICF).

Results
At T1, a significant hyperconnected network in the high-γ band was observed in several brain regions, including sensorimotor, limbic, temporal, and occipital lobes, which normalized by T2. Additionally, pp-TMS revealed disinhibition (reduced SICI) in M1 at ISI 2–3 ms at T1.

Conclusions
The study highlighted specific features of exercise-induced central fatigue. Post-exercise, the primary motor cortex became hyperexcitable, possibly as a compensatory response to peripheral fatigue. A complex network of cortical areas involved in cognition and behavior was hyperactivated, likely reflecting awareness of fatigue and self-protection decision-making processes. These changes were reversible, allowing subjects to return to baseline conditions.

Significance
This research provides insight into the neurophysiological mechanisms of central fatigue, emphasizing the brain’s adaptive responses to intense physical activity and their temporal dynamics.

Link (Clinical Neurophysiology) [Paywall]

 

Just posting because any new findings about what happens to the body after exercise/exertion might be relevant to ME/CFS.

Edit: I made a thread for posting this kind of research.

 

Is that central fatigue they are measuring or a temporary pause after a short run? ‘How brain reacts to a run in healthy volunteers for a 3km run’ is hardly the same as measuring soldiers coming back from a 5day awake exercise

I thought fatigue was when the body was exhausted - hence why CPET is used so it is to the point of exhaustion.

no wonder some of these specialties are confusing what works for well people to ‘recover’ from their morning short run vs serious illness where it’s been ongoing for years.

it’s like claiming to study gout therapies by taking some healthy volunteers and looking at their MRI after they wore high heels for an hour as if the toe pain was the same thing.

 

We already know exercise clears mind. No idea how one can connect cortical areas getting hyperactivated to self-protection. That takes a lot of imagination.

This old study on recovery from exercise might prove to be more relevant for ME/CFS and PEM.