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

Figures

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  Fig. 1. Experimental procedure. From left to right, the sequence includes recruitment, grouping, baseline measures (body composition, 20 m SRT, and resting-state EEG), the 8-week intervention period, and post-intervention tests (body composition, 20 m SRT, and resting-state EEG). The HIIT scheme followed a 40-s work / 20-s recovery pattern, with a 30-min session performed three days per week for 8 weeks. HIIT: high-intensity interval training; 20 m SRT: 20-meter shuttle run test

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  Fig. 2. Topographical distribution of resting-state EEG power across frequency bands. Each column represents a conventional EEG frequency band: delta (1–4 Hz), theta (4–8 Hz), alpha (8–13 Hz), beta (13–30 Hz), and gamma (30–50 Hz), from left to right. Rows 1–2 show the Control group at baseline and post-intervention; rows 3–4 show the HIIT group. Color bars represent log10-transformed power spectral density (Units: µV²/Hz). Warmer colors indicate higher power

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  Fig. 3. Schematic overview of PLV processing pipeline. The EEG data processing workflow included the following steps: (i) importing raw data; (ii) bad-channel detection and band-pass filtering (1–50 Hz); (iii) segmentation into 2-s epochs; (iv) independent component analysis (ICA) decomposition and ICA-based artifact correction; (v) bad-channel interpolation and re-referencing; (vi) automatic and manual artifact rejection using scalp topography; (vii) narrow-band filtering and Hilbert transform; and (viii) mean power-spectrum computation and estimation of the PLV. Abbreviations: PLV, phase-locking value; ICA, independent component analysis

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  Fig. 4. Intervention (Post). * P < 0.05, ** P < 0.01 vs. pre-intervention within the same group; # P < 0.05 vs. Control group at the same time point. PSD: power spectral density; F: frontal lobe; C: central lobe; T: temporal lobe; P: parietal lobe

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  Fig. 5. Pre- and post-intervention effects of the phase-locking value (PLV) within and between groups. (A) Changes in PLV connectivity values between functional brain regions in the HIIT group before and after the intervention across different frequency bands. Red lines indicate significant increases, and blue lines indicate significant decreases. (B) Mean PLV connectivity values across frequency bands, groups (HIIT vs. Control), and time points (pre- vs. post-intervention). * P < 0.05 vs. pre-intervention; #: P < 0.05. vs. Control group at the same time point. PLV: phase-locking value; F: frontal lobe; C: central lobe; T: temporal lobe; P: parietal lobe