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

/ Train Daly/
ideal weight for swimmers

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.

Lean Mass Development for Swimmers: Optimizing Body Composition

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​.

swimmers body fat percentage for elite swimmer

Lean Mass Development for Swimmers

Body Composition Changes in Elite 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.

olympic swimmer body fat

Elite Female Swimmers

Reliable Methods and Key Considerations

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.

ideal olympic swimmer body fat percentage

ideal olympic swimmer body fat percentage

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.

swimmer body male and female

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.


Dopsaj M, Zuoziene IJ, Milić R, Cherepov E, Erlikh V, Masiulis N, di Nino A, Vodičar J. Body Composition in International Sprint Swimmers: Are There Any Relations with Performance? Int J Environ Res Public Health. 2020 Dec 17;17(24):9464. doi: 10.3390/ijerph17249464. PMID: 33348744; PMCID: PMC7766121.

Roelofs EJ, Smith-Ryan AE, Trexler ET, Hirsch KR. Seasonal Effects on Body Composition, Muscle Characteristics, and Performance of Collegiate Swimmers and Divers. J Athl Train. 2017 Jan;52(1):45-50. doi: 10.4085/1062-6050-51.12.26. Epub 2016 Dec 1. PMID: 27905858; PMCID: PMC5293516.

Pyne DB, Anderson ME, Hopkins WG. Monitoring changes in lean mass of elite male and female swimmers. Int J Sports Physiol Perform. 2006 Mar;1(1):14-26. doi: 10.1123/ijspp.1.1.14. PMID: 19114734.


Alméras N, Lemieux S, Bouchard C, Tremblay A. Fat gain in female swimmers. Physiol Behav. 1997 Jun;61(6):811-7. doi: 10.1016/s0031-9384(96)00559-8. PMID: 9177551.

Mallett, A., Bellinger, P., Derave, W., Osborne, M., & Minahan, C. (2021). The age, height, and body mass of Olympic swimmers: A 50-year review and update. International Journal of Sports Science & Coaching, 16(1), 210-223. https://doi.org/10.1177/1747954120971797

Fleck SJ. Body composition of elite American athletes. Am J Sports Med. 1983 Nov-Dec;11(6):398-403. doi: 10.1177/036354658301100604. PMID: 6650717.

Cullen, Sarahjane & Fleming, James & Logue, Danielle & O'Connor, Joe & Connor, Brendan & Cleary, John & Watson, John & Madigan, Sharon. (2020). Anthropometric profiles of elite athletes. Journal of Human Sport and Exercise. 17. 10.14198/jhse.2022.171.14.

Mitchell LJG, Morris KS, Bolam KA, Pritchard-Peschek KR, Skinner TL, Shephard ME. The non-linear relationship between sum of 7 skinfolds and fat and lean mass in elite swimmers. J Sports Sci. 2020 Oct;38(20):2307-2313. doi: 10.1080/02640414.2020.1779491. Epub 2020 Jun 19. PMID: 32552507.