Acute Effects of Different Warm-Up Protocols in Competitive Young Swimmers

Acute Effects of Different Potentiation Protocols During Warm-Up in Competitive Young Swimmers: A Randomized Crossover Trial

Several warm-up strategies are commonly employed by athletes to optimize athletic performance and minimize the risk of injury. Recently, Post-Activation Performance Enhancement (PAPE) has been demonstrated to be effective in improving athletic performance. Nevertheless, the difference with the general warm-up is still unclear and poorly studied. Conventionally, short-term performance improvements achieved after brief periods of maximal activity have been attributed to PAP, a muscle memory mechanism that generates involuntary and short-lived effects (~28 seconds). This condition appears to be activated only by a history of localized maximal contractions. In the literature, various conditioning protocols with differing durations and intensities have been explored, often finding conflicting results in terms of athletic performance. In swimming, few PAPE warm-up protocols outside the pool have been studied, despite their potential usefulness considering the waiting times before competitions.

Therefore, this study explores the effects of three different warm-up protocols in young swimmers. Specifically, different exercise protocols will be included in the athletes' usual warm-up routine, aimed at improving athletic performance through PAPE effects. In line with existing literature, the performance parameters examined are the countermovement jump (CMJ) and the times recorded for covering race distances ( 25 m, 50 m, 100 m). In addition, skin temperature, heart rate (HR), muscle oxygen saturation (SmO2), and perceived exertion (RPE) are also measured after the protocols to investigate possible relationships with performance measures. Nevertheless, the primary aim of this study is to compare different warm-up protocols in young swimmers to maximize their athletic performance.

All outcome data will be expressed as mean ± standard deviation. The first warm-up section for all athletes will take place in the pool. Subsequently, baseline assessments (T0) will be conducted. Through a randomized study design, each participant will perform three plyometric protocols (squats with elastic bands, box jumps, or a combination of both).

To examine differences in the main outcomes, a repeated-measures ANOVA (4 conditions x 5 time points) will be conducted. When a significant condition × time interaction is detected, post hoc analyses to determine specific between and within-group differences. Effect sizes will be reported as partial eta squared (η²p). Statistical significance will be set at p < 0.05 for all analyses

Inclusion Criteria:

• Active participation in competitive training programs (at least 10 hours per week), at least one year of experience in competitions organized by the Italian Swimming Federation, and no recent injuries.
• Experience of resistance training for at least 6 months

Exclusion Criteria:

• Irregular training participation
• History of injuries in the 6 months prior to the study