Players with body fat higher than 13% showed significantly worse endurance. (Photo by Alexander Nadrilyanski from Pexels)

In A Nutshell

• The 13% threshold: In this study of 52 Brazilian pros, players with 13% body fat or higher covered less distance on an endurance shuttle run test that mimics game intensity

• One measurement matters most: A simple abdominal skinfold reading of 20 mm or more showed the strongest link to reduced aerobic performance—faster to check than complex fitness testing

• Sprints vs. stamina: Body fat correlated strongly with endurance but showed weak connections to jumping and short sprints, suggesting it affects sustained running more than explosive power

• Use with caution: These numbers came from pre-season testing in second-division Brazilian players and haven’t been validated across leagues, positions, or mid-season conditions

Professional soccer players have a new number to watch, and it has nothing to do with goals, assists, or minutes played. In a study of 52 male pros competing in Brazil, 13 percent body fat or higher was linked to lower endurance on a standard shuttle run test. A quick flag is 20 millimeters at the abdomen on a skinfold pinch.

Pedro Schons from Federal University of Rio Grande do Sul wanted to find out which body measurements actually mattered for soccer performance. His team measured everything from chest fat to calf thickness. Then, players went through a series of jumping tests, sprints, and the grueling Yo-Yo test (a shuttle run that mimics the repeated bursts of speed typical in matches).

One measurement stood out. Abdominal skinfold thickness had the strongest connection to how far players could push themselves aerobically. Players at 20 millimeters or higher tended to fade faster during the endurance test.

Why Belly Fat Hits Stamina Hardest

Extra body fat acts like dead weight. It demands oxygen and blood flow without helping a player move faster or last longer. During the constant direction changes and sprints in soccer, that extra tissue burns more energy and cranks up body heat, which accelerates fatigue.

A player’s overall weight told less of the story. Someone could weigh more but still outlast lighter teammates if that weight came from muscle. Where fat accumulated mattered more than the scale number.

When researchers crunched the numbers using chest, belly, and thigh measurements together, they landed on 13 percent body fat as a useful benchmark. Players above that line showed noticeably worse endurance. A simpler combo, just those three spots instead of seven, worked nearly as well as more elaborate methods, making it practical for teams with tight schedules.

Infographic of the entire study design and key findings. (Credit: Pedro Schons, Artur Avelino Birk Preissler, Rafael Grazioli, Júlio B. Mello, Guilherme Droescher de Vargas, Lucas Moraes Klein, Alexandra Ferreira Vieira and Eduardo L. Cadore. – License CC BY)

The Split Between Power and Endurance

Body fat barely budged the needle on jumping height or sprint speed. Those explosive movements depend more on muscle strength and how quickly the nervous system fires. Endurance is different. Lasting through 90 minutes requires cardiovascular efficiency, and extra fat undermines that by making every movement cost more energy.

A player approaching 13 percent might not notice any drop in their ability to win a header or blow past a defender on a breakaway. The decline shows up in the second half, when legs get heavy and that final sprint to pressure the ball comes a step slower.

What This Means for Soccer Players and Coaches

The study, published in Translational Exercise Biomedicine, examined players averaging 25 years old from three Brazilian teams during pre-season training. It included forwards, defenders, and midfielders, though the sample size didn’t allow testing whether different positions need different targets.

For coaches, a tape measure and calipers offer quick check-ins. If a player’s belly measurement creeps toward 20 mm or body fat inches up to 13 percent, that’s a flag to adjust training or nutrition before conditioning suffers.

These numbers come from fitness testing, not actual match statistics. A player could nail every body composition target and still underperform if their positioning is off or technical skills lag. Conversely, someone slightly above these benchmarks might dominate through superior game sense and skill.

An abdominal skinfold reading of 20 mm or more predicted diminished aerobic performance. (Credit: TatianaKim on Shutterstock)

The findings also haven’t been validated beyond this specific group. Pre-season fitness differs from mid-season sharpness. Second-division Brazilian players might have different optimal ranges than Premier League athletes or college players. Future research tracking these measurements across full seasons and different leagues would clarify how broadly the thresholds apply.

Practical Takeaways

This study gives teams concrete reference points instead of vague guidance about “staying lean.” The 20 mm belly measurement and 13 percent body fat threshold showed reliable connections to endurance in this group. Small changes might matter—dropping from 14 to 12 percent or trimming belly skinfold from 21 to 19 mm could translate to more ground covered when matches get tight.

Body fat equations used here work reasonably well but aren’t perfect. More precise methods like DEXA scans cost more and aren’t practical for weekly monitoring. For routine check-ins, the three-site skinfold approach hits the sweet spot between accuracy and convenience.

Players and staff now have specific numbers tied to measurable differences in how long someone can maintain intensity. Whether these exact thresholds hold up across different contexts remains an open question, but the core finding is straightforward: belly fat correlates with stamina more than any other single measurement, and a simple pinch test can flag potential issues.

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*Disclaimer: These findings show correlations between body composition measurements and performance on fitness tests, not cause-and-effect relationships or on-field match performance. These thresholds have not been validated across different leagues, competitive levels, playing positions, or seasons. Athletes and coaches should consult qualified sports medicine professionals and certified nutritionists before making decisions based on body composition data. *

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Paper Summary

Methodology

Researchers recruited 52 male professional soccer players (average age 24.6 years) from three Brazilian teams competing in a state championship second division. The study excluded goalkeepers and required all participants to have medical clearance. Players underwent body composition assessment through nine skinfold measurements at standardized anatomical sites using calibrated calipers, with each site measured twice by the same trained evaluator. Body fat percentage was calculated using four different protocols: Faulkner’s four-skinfold method, Pollock’s seven-skinfold method, and two variations of the Jackson and Pollock three-skinfold method. Physical performance testing included three types of vertical jumps measured via contact mat, a 20-meter sprint timed by photocells, and the Yo-Yo Intermittent Recovery Level 1 test, which involves progressively faster 20-meter shuttle runs with brief recovery periods until exhaustion.

Results

Abdominal skinfold thickness showed the strongest negative correlation with Yo-Yo test performance (r=-0.579). The sum of chest, abdominal, and front thigh skinfolds also correlated negatively with aerobic performance (rho=-0.518), as did body fat percentage calculated from these three sites using the Jackson and Pollock method (r=-0.534). Body mass demonstrated only moderate negative correlation with Yo-Yo test distance (r=-0.339). Relationships between body composition and anaerobic tests (jumps, sprint) were weaker and less consistent. ROC curve analysis identified optimal cutoff points: 20 mm for abdominal skinfold (sensitivity 92.7%, specificity 63.6%), 33 mm for the three-skinfold sum (sensitivity 68.3%, specificity 81.8%), and 13% for body fat percentage (sensitivity 95.1%, specificity 54.5%). Players meeting or exceeding these thresholds demonstrated significantly reduced Yo-Yo test performance.

Limitations

The study’s cross-sectional design during pre-season limits generalizability to other competitive periods when fitness levels differ. Geographic and competitive homogeneity—all participants came from Brazilian state-level teams—restricts broader applicability across different leagues and countries. Skinfold-based body fat equations, while correlated with more precise methods like DEXA scanning, may introduce measurement error. Physical tests serve as proxies for match performance but don’t capture technical, tactical, or psychological factors affecting actual game outcomes. The sample size, though adequately powered for correlation analysis, prevented position-specific subgroup analyses that might reveal different body composition standards for forwards versus defenders.

Funding and Disclosures

The research received funding from Brazil’s National Council for Scientific and Technological Development (CNPq), which supports Pedro Schons and Eduardo Lusa Cadore. The authors declared no conflicts of interest. Eduardo Lusa Cadore serves as an editor for Translational Exercise Biomedicine but was not involved in handling or reviewing this manuscript. The study received ethics approval (No. 2.903.811) from the Federal University of Rio Grande do Sul ethics committee and followed Helsinki Declaration guidelines.

Publication Details

Schons P, Preissler AAB, Grazioli R, Mello JB, de Vargas GD, Klein LM, Vieira AF, Cadore EL. “Associations between anthropometric outcomes and fat percentage with physical performance in professional soccer players: a cutoff points approach.” Translational Exercise Biomedicine. Published online October 8, 2025. doi:10.1515/teb-2025-0024.

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