This preliminary study assessed the feasibility of investigating the acute effects of High-Intensity Hybrid Training on squat jump performance in youth football players and identified operational challenges for future research. Ten male youth football players (19.3±0.4 years) completed four identical High-Intensity Hybrid Training sessions over four weeks. Squat jump height was measured before and after training using the My Jump 2.0 application. The protocol induced significant acute fatigue across all sessions (p<0.00), with mean squat jump height decreasing from 42.7±0.9 cm to 27.9±2.3 cm, representing a 34.7±4.3% reduction in performance. Large effect sizes (d>1.3) confirmed substantial physiological demand. Operational challenges identified included scheduling conflicts requiring flexible testing windows, insufficient familiarization for two participants necessitating additional practice trials, environmental variability suggesting the need for standardized indoor facilities, and post-assessment timing issues requiring additional staffing. The findings confirm the feasibility of conducting a full-scale investigation, demonstrate early evidence of significant acute fatigue from High-Intensity Hybrid Training, and provide critical operational insights for protocol refinement. Future studies should incorporate enhanced familiarization, environmental control, increased staffing, and additional neuromuscular measures.
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