Effect of an experimental fatigue protocol applied to the quadriceps femoris muscle of physically active persons

Abstract

The purpose of this study was to test an experimental fatigue protocol for the knee joint extensor muscles performed on an isokinetic dynamometer. Method: SPIRIT recommendations were applied. Participants were 40 healthy, young men and women. Protocol: The pre-fatigue quadriceps femoris peak torque during concentric maximum voluntary contractions (MVC) at 60º/s was measured. During the first protocol part, the task was to do MVC at 60°/s until a sequence of five concentric MVC was below 40% of its initial value. For the second part, intermittent quadriceps femoris muscle and hamstrings maximum voluntary isometric contractions for 30 s (ratio 2/1 seconds). Thirty seconds after the isometric MVC (post-fatigue), they did three concentric MVC. Then, after 5 minutes of absolute rest, they did two concentric MVC. Men and women showed a lower peak torque due to this protocol (p < 0.001). Conclusion: This protocol was effective for fatigue men and women's quadriceps femoris muscle.