Background. Post-activation potentiation (PAP) occurs after a previous potentiating stimulus (PP) and causes a sudden increase in muscle strength and performance. After muscular effort, this acute phenomenon manifests itself only if the athlete has rested enough. Fatigue is the ratio between excitation and contraction, dependent on physical activity. If, after performing physical activity with the purpose of potentiation, fatigue is present together with potentiation, fatigue will always prevail.
Objectives. This study examined two isometric methods for enhancing post-activation performance in track and field athletes.
Methods. The study sample consisted of 25 Croatian track and field athletes who compete in speed-explosive disciplines. The athletes were divided into two groups. One group performed a maximal isometric half-squat protocol (HS; pushing a stationary Olympic bar), and the second group performed maximum voluntary contraction (MVC) on the quadriceps and femoris muscles.
Results. Both groups performed an initial test, then a potentiating stimulus, and after a 5-minute rest, performed the final test again. The dependent t-test results showed no statistically significant difference between the initial and final measurements in the MVC group (p=0.39) and the HS group (p=0.80).
Conclusion. The isometric preparation protocols cannot positively influence the post-activation performance increase in the best Croatian athletes. No single protocol is more effective than the other.
