📚 Upside Studies: (1) Starters Experience Greater Weekly Match and Total Loads Than Non-Starters in a Professional Female Soccer Team (2) Effects of Sport Specialization on Pitching Biomechanics
In professional women’s soccer, managing training and match workloads is essential for optimizing performance, reducing injury risk, and maintaining squad readiness across a long competitive season. Unlike starters, non-starters often experience reduced match exposure, which may lead to substantial differences in accumulated weekly load that are not fully addressed through standard training practices. Understanding how match participation influences overall workload distribution is critical for designing effective load management strategies that support both performance and athlete health.
This study, titled “Starters Experience Greater Weekly Match and Total Loads Than Non-Starters in a Professional Female Soccer Team: An Exploratory Analysis Within the A-League Women’s Australian Competition,” examines differences in external load between starters and non-starters across training and match contexts. By quantifying match, training, and total weekly loads using GPS-derived metrics, the study provides applied insights into how workload imbalances emerge within elite women’s soccer squads and highlights practical considerations for individualized load management.
Study Summary – Key Findings and Statistics
Purpose:
This study investigated differences in external load, match load, and accumulated weekly load between starters and non-starters in a professional female soccer team competing in the Australian A-League Women. The aim was to better understand workload distribution across squad roles and identify potential risks for under- or over-loading players.
Authors and Affiliations
Michele Lastella 1,2,3,* , Nathan Elsworthy 2,3 , Dean J. Miller 1,2,3 , Mia Lundquist 4 , Fabio Serpiello 2,3,5 and Aaron T. Scanlan 2,3
1 Appleton Institute, Central Queensland University, Adelaide, SA 5034, Australia
2 School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, QLD 4700, Australia; n.elsworthy@cqu.edu.au (N.E.); a.scanlan@cqu.edu.au (A.T.S.)
3 S.P.O.R.T. Research Cluster, Central Queensland University, Rockhampton, QLD 4700, Australia
4 Adelaide United Football Club, Adelaide, SA 5007, Australia
5 Institute for Health and Sport, Victoria University, Melbourne, VIC 3011, Australia * Correspondence: m.lastella@cqu.edu.au; Tel.: +61-413-407-956
Researchers with expertise in applied sport science and professional women’s soccer, working within the Australian high-performance sport system.
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Study Design
Design: Observational, exploratory, longitudinal analysis
Competition Context: A-League Women (Australia)
Data Collection Period: Competitive season
Technology Used: GPS-derived external load metrics during training and matches
Participants
Sample Size:
Professional female soccer players from one A-League Women team
Player Classification:
Starters: Players completing ≥60 minutes of match play
Non-Starters: Players completing <60 minutes or not selected
External Load Metrics Assessed
Key GPS-derived variables included:
Total distance
High-speed running distance
Sprint distance
PlayerLoad™
Weekly accumulated load (training + match)
Match load vs training load contribution
Key Findings – Starters vs Non-Starters
Match Load
Starters accumulated substantially greater match loads than non-starters across all external load metrics
Match play was the primary driver of weekly load differences between groups
Weekly Total Load
Starters experienced significantly higher total weekly loads, despite similar training participation
Non-starters were unable to compensate for reduced match exposure through training alone
Training Load
Training loads were relatively similar between starters and non-starters
Training sessions did not sufficiently offset match load discrepancies
Load Distribution Insights
Match exposure accounted for the largest proportion of weekly load variance
Non-starters consistently accumulated lower chronic loads, potentially increasing injury risk when suddenly required to compete
Starters were exposed to greater cumulative physical stress, raising considerations around fatigue management and recovery
Practical Implications for Performance & Health
Load Management
Coaches and sport scientists should not assume training alone can equalize weekly load between starters and non-starters
Supplementary conditioning may be required for non-starters to maintain match readiness
Injury Risk Considerations
Chronic under-loading in non-starters may increase injury risk during sudden increases in match exposure
Chronic over-loading in starters may elevate fatigue and soft-tissue injury risk without appropriate recovery strategies
Squad Rotation & Planning
Strategic rotation, individualized top-up sessions, and post-match conditioning may help reduce load imbalances
Monitoring weekly and rolling load metrics is critical for long-term athlete availability
Limitations
Single-team analysis limits generalizability
Small sample size inherent to professional squads
External load only; internal load and wellness metrics were not included
Future Research Directions
Multi-team and multi-season analyses in women’s professional soccer
Integration of internal load, recovery, and injury data
Evaluation of top-up conditioning strategies for non-starters
Practical Recommendations to Teams
Individualize Weekly Load Targets
Rather than applying uniform training loads, staff should tailor weekly volume and intensity based on match minutes played.
Implement Non-Starter Top-Up Strategies
Post-match conditioning or modified training sessions can help non-starters maintain chronic load and match readiness.
Protect Starters Through Recovery Optimization
Higher match loads in starters necessitate enhanced recovery protocols to mitigate cumulative fatigue.
Monitor Chronic Load Trends
Tracking rolling weekly loads can help identify players at risk of both under- and over-exposure.
Align Performance and Medical Staff
Integrated decision-making ensures load management strategies balance performance readiness with injury prevention.
Conclusion
This study highlights systematic workload disparities between starters and non-starters in professional women’s soccer, driven primarily by match exposure rather than training load differences. Without targeted intervention, these disparities may increase injury risk and reduce squad readiness. The findings reinforce the importance of individualized load management strategies to support performance, health, and availability across the entire squad.
Introduction
In adolescent baseball, the trend toward early sport specialization—focusing on a single sport at the exclusion of others—has raised significant concerns regarding injury risk and burnout1111. While specialization is often pursued to enhance skill development, its impact on the fundamental mechanics of pitching is not yet fully understood2222. Because improper biomechanics are a known contributor to shoulder and elbow injuries, identifying how specialization levels alter these movements is vital for both performance and player safety3.
This study, titled “Effects of Sport Specialization on Pitching Biomechanics in Adolescent Baseball Pitchers,” investigates the kinetic and kinematic differences among high school pitchers categorized by their level of specialization4444. By utilizing high-speed motion analysis, the researchers sought to determine if dedicated year-round focus on baseball leads to specific biomechanical adaptations that could either improve performance or increase the risk of overuse injuries55555.
Study Summary – Key Findings and Statistics
Purpose
The study aimed to examine the relationship between sport specialization levels (low, moderate, and high) and pitching biomechanics in adolescent male pitchers6666. The researchers hypothesized that kinetics, kinematics, and peak velocities would vary significantly based on the athlete’s level of specialization7.
Authors and Affiliations
Alexandra L. Johnson, MD; Meghan R. Caballero, MD; Shayne Fehr, MD; Cody C. Dziuk, BS; and Janelle A. Cross, PhD88.
Affiliation: Department of Orthopaedic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin99.
The research team consists of medical doctors and PhD researchers specializing in orthopaedics and biomechanics10101010.
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Study Design
Design: Descriptive laboratory study (Level of Evidence: 3)11.
Data Collection: Participants underwent a single biomechanical testing session during the preseason12121212.
Technology: An 8-camera Raptor-E motion analysis system (300 fps) and 47 reflective markers were used to capture motion13. Pitch velocity was measured using a radar gun14.
Statistical Analysis: 1-way ANOVA and Kruskal-Wallis tests were used to compare groups ($P\le0.05$ for significance)15151515.
Participants
Sample Size: 46 right-handed adolescent male baseball pitchers16.
Criteria: At least 3 years of pitching experience, no current pain, and no history of surgery17.
Specialization Breakdown: 10 low-level, 19 moderate-level, and 17 high-level specialized pitchers18.
Specialization Metric: Determined by a 3-question scale: 1) Is baseball your main sport? 2) Have you quit other sports? 3) Do you play/practice $>8$ months per year?19191919.
Key Findings – High vs. Low Specialization
The study found five key biomechanical differences as specialization levels increased2020:
Kinematic Differences (Movement)
Stride Length: Significantly increased from low-level (74% of height) to high-level (82.9% of height) specialization ($P=0.03$)21212121.
Hip-Shoulder Separation: Increased significantly at foot contact ($P=0.01$); low-level pitchers averaged $21.9^{\circ}$ while high-level averaged $30.0^{\circ}$22222222.
Peak Velocities
Maximum Torso Rotation Velocity: Increased significantly from $930.5^{\circ}/s$ in low-level to $1020.0^{\circ}/s$ in high-level pitchers ($P=0.03$)23232323.
Maximum Shoulder Internal Rotation (IR) Velocity: Increased significantly from $4284.2^{\circ}/s$ (low) to $4827.7^{\circ}/s$ (high) ($P=0.03$)24242424.
Kinetic Differences (Forces)
Shoulder Distraction Force: Highly specialized pitchers experienced significantly higher force (0.96 N/%BW) compared to low-specialized pitchers (0.81 N/%BW) ($P=0.03$)25252525.
Non-Significant Findings
There were no significant differences in age, height, weight, or actual pitch speed across specialization levels26262626.
Practical Implications for Performance & Health
Performance Benefits: Highly specialized pitchers exhibit traits often linked to higher velocity, such as increased stride length and better hip-shoulder separation2727272727272727.
Injury Risk: The increase in shoulder distraction force and high-velocity rotations may predispose highly specialized pitchers to rotator cuff or labral injuries2828282828282828.
The “Efficiency” Gap: Despite having “faster” biomechanics (e.g., higher torso rotation velocity), specialized pitchers did not actually throw faster in this study, suggesting potential coordination inefficiencies or fatigue29292929.
Limitations
Localized Sample: Participants were from a single youth program, which may not represent all adolescent pitchers30.
Self-Reporting: Specialization levels were determined by questionnaires, which are subject to bias31.
Snapshot Data: The study only measured performance at one point in time during the preseason32.
Sample Size: The small, uneven group sizes may have limited the ability to detect differences between “moderate” and “high” levels33.
Practical Recommendations to Teams
Monitor Shoulder Health: Since specialized pitchers face higher shoulder distraction forces, staff should prioritize posterior capsule stretching and rotator cuff strengthening34343434.
Focus on Stride and Mechanics: Coaches should ensure that increased stride length—found in specialized players—is maintained with proper form to avoid placing excessive stress on the medial elbow35353535.
Encourage a Balanced Approach: Parents and coaches should promote well-rounded athletic engagement rather than early, intense specialization to mitigate injury risks36.
Individualized Training: Recognize that specialized pitchers may have different biomechanical profiles requiring tailored recovery and mechanics-based training37.
Conclusion
Adolescent pitchers with high levels of sport specialization exhibit distinct biomechanical differences compared to their multi-sport peers, including increased stride length and higher rotational velocities38383838. While these adaptations may offer performance advantages, they are accompanied by increased forces on the shoulder joint39393939. These findings emphasize the need for a balanced approach to youth sports that fosters skill development while protecting long-term athlete health40.
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