Various forms of stretching have long been an integral component to the pre-training warm-up routine. Teams would often line up in rows on the field and count out their ~15 seconds stretches in unison, starting from their upper body and moving progressively to their lower body. However, the effects of static stretching on strength and power performance were called into question. This sparked a line of research that aimed to determine if athletes should static stretch before training and competing. It’s been demonstrated that excessive static stretching (e.g., holding stretches for > 60 s) may cause acute reductions in force and power output of the stretched muscles. However, factors such as stretching type, proximity to training/competition and inclusion of an active warm-up following stretching need to be considered, as these may modify the effects of static stretching on performance.
A new study published ahead of print in the Journal of Strength and Conditioning Research compared the effects of various stretching protocols on jumping and sprinting performance in a team of soccer players. In a randomized, cross-over design, 12 male soccer players (17-18 years old) performed four stretching interventions and a control condition followed by range of motion (sit and reach test) squat-jump, countermovement-jump and 30 m sprint testing. Subjects performed two familiarization sessions to learn the stretching protocols. The interventions involved 3 sets of 30 second active stretching (holding elongated stretch position), ballistic stretching (oscillating stretch every second), passive stretching (partner-assisted technique causing a more intense stretch) and proprioceptive-neuromuscular facilitation (PNF) stretching using the hold-relax technique of the lower limbs. All stretching was supervised or assisted by a physical therapist. The control condition involved passive rest for the same time duration.
The results showed that all four of the stretching interventions significantly improved range of motion in the sit and reach test compared to control. Both passive stretching and PNF stretching protocols resulted in decrements in jump height, peak power and relative power during both the squat-jump and countermovement jump (mean reductions ranged from -1.33 to -5.98%). By contrast, the effects of passive and ballistic stretching on jump performance were trivial. While no significant differences were detected for sprinting speed, the control condition had the fastest sprint times and the PNF stretching resulted in the slowest sprint time (very large effect size). Therefore, it appears that 3 sets of 30 seconds of active or ballistic stretching can improve range of motion without adversely affecting performance. However, passive and PNF stretching should be avoided prior to training due to the observed reductions in jumping performance.
Reference:
de Paula Oliveira, L., Vieira, L. H. P., Aquino, R., Manechini, J. P. V., Santiago, P. R. P., & Puggina, E. F. (2017). Acute Effects Of Active, Ballistic, Passive And Proprioceptive Neuromuscular Facilitation Streching On Sprint And Vertical Jump Performance In Trained Young Soccer Players. The Journal of Strength & Conditioning Research.
