Brain activity is studied across frequency bands, each linked to distinct functions of the central nervous system. Gamma oscillations are particularly associated with neuronal integration, attentional processes, and cortical excitability. While physical exercise has been shown to modulate brain activity, evidence on its specific impact on gamma oscillations remains scarce. The aim of this study was to examine cortical gamma activity in the sensorimotor area immediately before and after a high-intensity interval training (HIIT) protocol. Participants completed a cycling task consisting of ten 20-second bouts at 90% of individual capacity, interspersed with 40-second active pauses at 50%. Electroencephalographic activity was recorded in resting state (eyes closed) before and after exercise, and gamma power spectral density (PSD) was extracted from the sensorimotor area. Spectral analysis was performed using MATLAB and EEGLAB, with non-parametric tests applied to compare conditions. Results revealed a significant post-exercise increase in gamma power relative to baseline, with a consistent pattern across participants. These preliminary findings align with previous evidence, suggesting that HIIT may acutely enhance cortical excitability reflected in gamma activity, underscoring the potential role of exercise-induced brain modulation in neuroscience research.