Study aim: To assess the acute effect of the proprioceptive neuromuscular facilitation method (PNF) on the explosive strength of lower extremities of male soldiers.

Material and methods: A group of 26 male soldiers performed two exercise sessions on different days, in a random order: without stretching (control exercise) or by applying PNF (experimental exercise). Before and after the PNF (0, 10, 20, 40 and 60 min), 3 vertical counter-movement jumps on a tensometric platform were executed.

Results: CMJ results in the experimental sessions were significantly (p<0.001) decreased after the PNF exertion in relation to the initial (pre-session) value. No significant post-session decreases were found in the control exercise. However, the differences between the experimental and control results were significant (p<0.05) only immediately after the PNF exertion and 10 min later.

Conclusion: The PNF method negatively affects the vertical jump performance and, thus, ought not to be used as part of warm-ups.