# Effects of a Short-Term Ballistic Training Program on Performance and Strength Deficit in Elite Youth Female Soccer Players

## TL;DR

A short ballistic training program improved strength and speed in young female soccer players without reducing their ability to produce force quickly.

## Contribution

This is the first study to show that ballistic training alone can enhance neuromuscular performance in female soccer players without increasing strength deficit.

## Key findings

- Significant improvements in vertical jumps, sprint speed, and strength were observed after the training program.
- Strength deficit remained unchanged despite performance gains, indicating no compromise in force production at higher velocities.
- The results suggest that velocity-focused ballistic training can optimize physical development in team-sport athletes.

## Abstract

This study examined the effects of a short-term ballistic training program on neuromuscular performance and strength-deficit (SDef) in elite youth female soccer players. Twenty-two under-20 athletes completed a 4-week intervention during the pre-season phase, comprising 12 loaded and 8 unloaded ballistic training sessions performed at maximal intended velocity. Pre- and post-intervention assessments included vertical jumps (squat jump [SJ], countermovement jump [CMJ]), sprinting speed (5, 10, and 20 m), one-repetition maximum (1RM) and peak force (PF) in the half-squat (HS), and peak power and velocity during jump squats (JS) at 30% of 1RM. SDef was calculated as the percentage difference in PF between 1RM in the HS and 30% 1RM. Significant improvements were observed in SJ, CMJ, sprint speed, 1RM-strength, and bar-derived mechanical outputs (ES = 1.18–1.66; p < 0.05), with no significant changes in SDef. These results indicate that elite youth female soccer players can improve strength-, power-, and speed-related capacities without compromising force production at higher movement velocities (thus maintaining their SDef). The improvements observed likely reflect the combined effect of a high-frequency, velocity-oriented training approach and a concurrent reduction in traditional technical–tactical (i.e., soccer-specific) training volume. This is the first study to demonstrate that ballistic exercises alone—when properly structured—can enhance neuromuscular performance in female soccer players without increasing SDef. These findings provide practical guidance for practitioners aiming to optimize physical development in team-sport athletes without relying on heavier training loads or extended resistance training sessions—and, especially, without compromising their ability to apply force at higher velocities.