Effects of Different Strength and Conditioning Programs Variations on Performance Variables in Professional Female Soccer Players

Abstract

Soccer is the world’s most popular sport, and women’s participation has grown rapidly in recent decades, reaching new levels of professionalization and global visibility. Despite this progress, research on female players remains limited compared to their male counterparts, particularly regarding evidence-based training approaches. This doctoral thesis investigates the effects of strength and sprint-based training interventions on the physical fitness and match performance of female soccer players. Although women’s soccer has gained remarkable popularity and professionalization in recent decades, research remains disproportionately focused on male athletes, leaving significant gaps in evidence-based training guidelines tailored to women. Through three complementary studies, this work evaluates (i) the short-term impact of in-season strength training in adolescent players, (ii) the comparison between traditional and integrated sprint training in professional players, and (iii) the long-term effects of structured strength training across two competitive seasons in youth female athletes. All three studies followed an experimental intervention design, applying specific training programs over defined periods and assessing pre- and post-intervention changes in performance. The research employs physical fitness tests (e.g., countermovement jump, aerobic capacity, sprint performance) and GPS-based match external load metrics (e.g., total distance, very-high-speed running, number of sprints, and maximum velocity). The results indicate that short-term strength training enhanced fitness and match outputs in youth players, specific sprint training method led to higher benefits in professional players, and long-term strength training promoted consistent and lasting improvements. Collectively, this thesis advances current knowledge in sports science by providing evidence-based recommendations to optimize periodization, conditioning, and injury prevention strategies in women’s soccer