Improving Swim Performance: The Importance of Body Composition in Elite Swimmers

/ Train Daly/

In 2011 I wrote an article on Body Fat Comparisons that continues to get a lot of readers. To follow up on that I wanted to share some of the evidence and approaches to lean mass development for swimmers. Body composition is crucial for athletic performance, particularly in swimming, a sport that demands high physicality. Elite swimmers' physical makeup is extensively studied due to its strong correlation with water performance. Measurements such as body mass, height, skin-folds, and lean mass index (LMI) are used for analysis.

Modern elite male swimmers are generally heavier and larger than their predecessors, with an average height of 183.8 cm and weight of 78.4 kg, and a body fat percentage of 8. The relationship between body composition and performance is essential for enhancing future performance. Lean mass (LM) significantly affects performance, especially in the 100-m front-crawl, as it is a major component of propulsion force. Swimmers are advised to increase muscle mass through resistance training and maintain a balanced diet rich in carbohydrates, proteins, and fats. Coaches can expect a twofold greater increase in lean mass in male swimmers within and between seasons compared to female swimmers​.

Elite female swimmers experience body composition changes during a season. A study indicated an average height of 173.4 cm and weight of 62.8 kg, with a body fat percentage of 15.79% for university-level swimmers. Despite the correlation between height and performance in some events, this is not consistent across all swimming categories, compared to lean mass.

For elite swimmers, the most reliable methods for assessing body fat and lean body mass (LBM) include hydrostatic weighing, DEXA scans, Bod Pods, skinfold measurements, and research-grade bioelectrical impedance scales. While commercial scales can be less accurate, they are still useful for tracking body composition trends over time at home. It's important to remember that daily weight fluctuations of 2-3% can occur due to changes in hydration, impacting body fat and LBM readings. Therefore, swimmers and coaches should focus on maintaining muscle mass throughout the season, which can be challenging as training volume ramps up, resistance training time may decrease, and recovery through sleep and nutrition becomes more crucial.

Swimmers should aim to build lean mass during the off-season and pre-season, when they can dedicate more time and energy to resistance training. To maintain lean mass during the competitive season, they should engage in at least two resistance training sessions weekly, focusing on lower volumes of strength and power. Adequate caloric intake, especially from carbohydrates, is essential to prevent muscle loss and to provide energy for training. Additionally, sufficient protein intake is necessary to support muscle maintenance and repair.

In conclusion, the body composition of elite swimmers is a complex interplay of factors that include height, weight, lean mass, and body fat percentage. These factors are meticulously monitored and managed to optimize performance. As research continues to uncover the nuances of how body composition affects swimming performance, training and conditioning programs are likely to become even more specialized and effective, keeping the evolution of elite swimming ongoing.


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