Effect of a Core Endurance Fatigue Protocol on Isokinetic Hamstring Strength and Flexibility in Male Soccer Players: An Exploratory Study Publisher Pubmed



Hovanloo F ; Pourahmad K ; Shahpar F M
Source: Physical Therapy in Sport Published:2026

Abstract

Background: Hamstring injuries are common in soccer, and fatigue-induced alterations in core function may influence neuromuscular control and hamstring performance. Objective: To investigate the acute effects of a core endurance fatigue protocol on isokinetic hamstring strength and active knee extension (AKE) range of motion in male soccer players. Methods: Thirty male soccer players participated in this pre-post experimental study. Their mean age was 25 ± 3.2 years, mean height was 179.4 ± 6.6 cm, mean weight was 74.1 ± 12.3 kg, and mean sports experience was 8.3 ± 2.1 years. Participants underwent pre- and post-fatigue assessments of concentric and eccentric hamstring peak torque, functional hamstring-to-quadriceps ratios, and AKE flexibility following a core endurance fatigue protocol. Results: Following fatigue, eccentric hamstring strength and the functional hamstring-to-quadriceps ratio at 240°/s decreased significantly. The changes in the functional hamstring-to-quadriceps ratio at 60°/s and AKE flexibility were smaller and not consistently significant after adjustment. Conclusion: Core endurance fatigue is associated with acute neuromuscular changes in variables linked to hamstring function. These exploratory findings suggest that core endurance may be relevant in injury prevention, although prospective studies are needed to establish clinical relevance. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.