The Effect of a Debilitating Fatigue Session on Shoulder Muscle Strength of Young Bodybuilders

Introduction: shoulder muscle fatigue in exercise is very common among bodybuilders. Fatigue can lowers the performance quality and seriously damage athletes’ shoulder joints. This study aimed to determine the effect of fatigue on the force of flexor, extensor, elevator, depressor, retractor, and abductor shoulder muscles in young bodybuilders after a session of debilitating fatigue. Materials and Methods: In this quasi-experimental study with a pre-test and post-test design, 25 active athletes in the field of bodybuilding (age: 26.12±2.78 years, height: 1.82±0.035 m, weight: 78.92±4.23 kg, BMI: 23.71±1.40 kg / m2, and sport history: 2.96±0.97 years) were selected. Before and after the fatigue, the force of flexor, extensor, elevator, depressor, retractor, and abductor muscles of shoulder was evaluated using a portable tensile-compression tachometer. To analyze the statistical part, the paired samples t-test was used to compare the fatigue protocol. Results: The results of the study showed a reprise of debilitating fatigue reduced the force of flexor (P=0.001), extensor (P=0.001), elevator (P=0.001), depressor (P=0.001), retractor (P=0.001), and abductor (P=0.001) of shoulder muscles. Conclusion: In general, the results of the present study showed the effect of fatigue on the reduction of flexor, extensor, elevator, depressor, retractor and abductor muscles of the shoulder, and this force decrease can be a factor for reducing performance quality in fatigue conditions and probably increasing the risk of injury in athletes