Author: Santiago Zabaloy et al
Journal: The Journal of Strength and Conditioning Research

AI written summary

This case study examined how a 4-month preparation period affected body composition and physical performance in 27 elite players from the Chilean women’s national team in the lead-up to the 2019 FIFA Women’s World Cup. Measurements were taken at three time points (TP1, TP2, TP3) for body composition, maximal strength, 10-m sprint, and countermovement jump (CMJ) performance.

Key Findings

Body Composition Improved Substantially

Over the preparation period, players showed:

• Lower sum of 6 skinfolds (+6SF)
• Reduced fat mass percentage (FM%) (5–16% reductions)
• Higher muscle mass percentage (MM%) (4–6% increases)

Body mass did not significantly change, suggesting a favourable shift from fat mass to muscle mass.

Strength Increased Markedly

Players improved across all strength-related measures:

• Higher squat 1RM (absolute and relative)
• Higher mean propulsive velocities at loads from 20–60 kg
  These gains indicate notable improvements in lower-body force production and neuromuscular performance.

Speed and Power Improved

• 10-m sprint times decreased progressively across all three phases (1.6–4.9% faster)
• CMJ height increased, particularly between mid- and post-testing

These results reflect enhanced acceleration capacity and vertical power.

Training Program Characteristics

The 16-week program combined:

• Moderate-load velocity-focused resistance training (30–60% 1RM)
• Linear and multidirectional speed work
• Small-sided games and tactical sessions
• Regular technical–tactical training

The authors highlight that high-speed, submaximal resistance work may be sufficient to drive strength–power improvements in elite female players.

Practical Implications

• Monitoring body composition together with performance tests provides better insight into physical readiness.
• Moderate-load, high-velocity strength training can effectively improve strength, jump, and sprint abilities.
• Regular testing every 3–4 weeks helps coaches make timely adjustments.
• Changes in FM% and MM% appear closely linked to gains in speed, power, and strength.

Conclusion

A structured, four-month periodized program led to significant and meaningful improvements in body composition, strength, speed, and explosive power in elite female footballers preparing for the World Cup. These findings provide rare longitudinal data from a women’s national team and offer valuable benchmarks for practitioners working in elite women’s football.