Post-match changes in biomarkers and fatigue-related physical performance parameters in adult amateur soccer players: the effects of fasting

Ramadan fasting poses unique physiological challenges for athletes, particularly in hot and arid environments. Understanding its effects on post-match recovery and performance is crucial for optimizing training and competition strategies. Eighteen male amateur soccer players (25.5 ± 3.2 years) from a regional club in southern Algeria were evaluated before, during, and after Ramadan. Blood biomarkers—including creatine kinase (CK), C-reactive protein (CRP), red and white blood cells (RBCs, WBCs), hemoglobin (HGB), hematocrit (HCT), and platelets (PLTs)—were measured. Physical performance was assessed using the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1), countermovement jump (CMJ), and 20 m sprint tests. Repeated-measures ANOVA and Friedman tests were used to detect differences across periods (p < 0.05). Significant reductions in CRP, WBCs, PLTs, HGB, and CK were observed during Ramadan compared with pre- and post-fasting periods, whereas HCT and RBCs remained stable. Yo-Yo IR1 performance declined significantly during Ramadan, while CMJ and sprint performance showed no significant changes. These findings indicate a selective reduction in aerobic capacity with maintenance of anaerobic and explosive performance. Ramadan fasting induces measurable alterations in inflammatory, hematological, and muscle-damage markers among soccer players in hot desert conditions. Although aerobic performance is compromised, short-duration and power-based efforts remain unaffected. Tailored hydration, nutrition, and training strategies adapted to fasting and hot environmental conditions are recommended to support recovery and performance, while accounting for inter-individual variability among adult amateur players.