The Effect of Contrast Training on Neuromuscular Fatigue: A Feasibility Study for Elite Football Development

Abstract

Introduction: Contrast training (CT), the sequential combination of heavy resistance exercises and plyometrics, is a potent method for developing athletic power. However, the acute neuromuscular fatigue response to CT in football players and, consequently, its feasibility as a consistent training stimulus are not well established. Understanding this acute response is the first step toward optimizing long-term training prescription. Objective: This preliminary study aimed to determine the consistency and magnitude of acute neuromuscular fatigue induced by a specific CT protocol in trained football players, thereby assessing its feasibility as a reliable method for imposing mechanical tension and metabolic stress. Methods: Ten male football players (age: 19.3 ± 0.4 years) participated in a repeated-measures design involving four identical CT sessions. Each session comprised one set of two back squat repetitions at 80% of one-repetition maximum (1RM), immediately followed by ten squat jumps. Squat jump height (cm) was measured pre- and one-minute post-session using the My Jump app. The percentage reduction in jump height quantified acute fatigue. Descriptive statistics and paired t-tests (α = 0.05) were used to compare pre- and post-test performance. Results: The CT protocol induced a highly significant and consistent acute fatigue response, with squat jump height decreasing by 29-32% after each session (p < 0.00). Individual reductions ranged from 20–45%, but the consistency of the mean effect across all four sessions (Cohen's d > 2.5) confirms the protocol's reliability in inducing substantial neuromuscular fatigue. Conclusion: This preliminary study confirms the feasibility of using this specific CT protocol to consistently and acutely impair neuromuscular performance in football players. The consistent fatigue pattern validates its use as a controlled stimulus for imposing mechanical tension (via heavy back squats) and metabolic stress (via repeated squat jumps). However, the authors acknowledge that future investigations should address the current study's limitations by including larger and more diverse samples, incorporating control or comparison groups, and assessing multiple physiological indicators such as electromyography, blood lactate, and heart rate responses. Extended monitoring of recovery patterns and chronic adaptations to contrast training will further enhance the scientific and practical contributions of this research.