High-intensity interval training modulates neural oscillations and inter-regional connectivity in college students

High-intensity interval training (HIIT) has been proposed as a time-efficient strategy to enhance brain health, yet its longer-term neural signatures remain unclear.

In a randomized, assessor-blinded, parallel-group study, 32 healthy undergraduates (18-25 years) completed either 8 weeks of supervised HIIT (30 min/session, 3 sessions/week) or a usual-activity control. Body composition was measured before and after the intervention, and maximal oxygen uptake (VO₂max) was assessed using the 20-m shuttle run test (20 m SRT). Resting-state EEG was recorded at baseline and post-intervention. Power spectral density (PSD) and phase-based connectivity were quantified across canonical frequency bands.

HIIT increased VO₂max and skeletal muscle mass and reduced body fat percentage compared with baseline, while no meaningful changes were observed in controls. Resting-state EEG showed increased delta-theta-alpha power and inter-regional phase synchronization, alongside reduced beta-gamma power/connectivity.

8 weeks of HIIT were associated with frequency-specific modulation of cortical oscillations and large-scale functional coupling at rest. These findings suggest that time-efficient exercise paradigms may promote neural network reorganization, with potential benefits for cognitive and motor function.