Skip to main content
. 2021 Sep 16;12:691919. doi: 10.3389/fphys.2021.691919

Table 2.

The summary of the sample demographics of each study included for analysis.

Source Sample Tanner stage Years of experience Pool length Race/trial event FINA points
Abbes et al. (2018) n = 14 boys: 13.00 ± 2.00 years n.a. At least 4 years 50 m 50 m Freestyle 520.00 ± 98.00
Abbes et al. (2020) n = 17 boys: 13.00 ± 2.00 years n.a. At least 4 years 50 m 50 m Freestyle 520.00 ± 98.00
Abbott et al. (2021) n = 48 boys (between 10 and 13 years) Maturity status (years pre/post peak height velocity): between −2.4 ± 0.29 and 0.2 ± 0.46 n.a. 50 m 200 m Freestyle
Alshdokhi et al. (2020) n = 28 boys: 12.60 ± 2.60 years n.a. n.a. 25 m 50 m and 100 m Freestyle, Backstroke n.a.
Amaro et al. (2017) n = 21 boys: 12.70 ± 0.80 years 2.10 ± 0.40 At least 2 years 25 m 50 m Freestyle n.a.
Barbosa et al. (2010) n = 38 boys: 12.53 ± 0.58 years 1–2 n.a. 25 m 200 m Freestyle n.a.
Barbosa et al. (2014) n = 34 girls and 33 boys: 12.83 ± 1.26 years 1–2 At least four years 25 m 100 m Freestyle n.a.
Barbosa et al. (2015) n = 49 boys: 12.51 ± 0.77 years; 51 girls: 12.24 ± 0.71 years 1–2 n.a. 25 m 100 m Freestyle n.a.
Barbosa et al. (2019) n = 75 boys: 11–13 years 1–2 At least two years n.a. 100 m Freestyle n.a.
Bielec and Jurak (2019) n = 26 boys: 12.10 ± 0.50 years; 15 girls: 12.20 ± 0.50 years Boys: 1.80 ± 0.60
Girls: 2.10 ± 0.70
2.40 ± 0.50 25 m 50 m Freestyle, and 200 m Individual Medley Boys 50 m: 202.00 ± 64.40
Girls 50 m: 279.20 ± 58.30
Boys 200 m: 211.50 ± 55.90
Girls 200 m: 280.60 ± 46.40
Costa et al. (2011) n = 242 boys n.a. n.a. n.a. 50 m, 100 m, 200m, 400 m, 800 m, and 1500 m Freestyle n.a.
de Mello Vitor and Böhme (2010) n = 24 boys: 13.00 ± 0.70 years 3–4 3 to 4 years 50 m 100 m Freestyle n.a.
Denadai et al. (2000) Beginners: n = 4 boys and 6 girls: 11.20 ± 0.90 years Trained: n = 3 boys and 3 girls: 11.10 ± 0.90 years n.a. Beginners: 1–2 years; Trained: 3–5 years 25 m 50 m, 100 m, and 200 m Freestyle n.a.
Duché et al. (1993) n = 25 boys: 11.30 ± 1.00 years 1 2 years n.a. 50 m, 100 m, 200m, and 400 m Freestyle n.a.
Ferraz et al. (2020) Under 12 level: n = 25 girls (12.48 ± 0.30 years); n = 24 boys (12.69 ± 0.26 years) Under 13 level: n = 23 girls (11.63 ± 0.28 years) n.a. n.a. 25 m 50 m, and 400 m Freestyle n.a.
Ferreira et al. (2019) n = 14 boys: 11.90 ± 1.08 years; 29 girls: 10.74 ± 0.91 years Boys: 2.93 ± 0.95
Girls: 2.71 ± 1.15
n.a. 25 m 400 m Freestyle n.a.
Ferreira et al. (2021) n = 24 boys: 12.51 ± 0.99 years; 10 girls: 11.24 ± 0.88 years Boys: 2.94 ± 1.04
Girls: 3.05 ± 1.10
n.a. n.a. 400 m Freestyle n.a.
Figueiredo et al. (2016) n = 51 boys and 52 girls: 11.80 ± 0.80 years n.a. n.a. 25 m 25 m Freestyle trial n.a.
Garrido et al. (2010a) n = 16 boys and 12 girls: 12.01 ± 0.56 years 1–2 n.a. 25 m 25 m and 50 m Freestyle n.a.
Garrido et al. (2010b) n = 14 boys and 11 girls: 12.08 ± 0.76 years 1–2 n.a. 25 m 25 m and 50 m Freestyle n.a.
Geladas et al. (2005) n = 178 boys: 12.78 ± 0.05 years; 85 girls: 12.68 ± 0.06 years Boys' biological age: 14.17 ± 0.13
Girls' biological age: 13.47 ± 0.13
n.a. 50 m 100 m Freestyle n.a.
Hue et al. (2013) n = 61 boys and 65 girls: 12.00 ± 1.30 years 1–2 n.a. 50 m 400 m Freestyle n.a.
Jürimäe et al. (2007) n = 15 boys: 11.90 ± 0.30 years 1–2 3.00 ± 1.10 25 m 400 m Freestyle n.a.
Kjendlie et al. (2004a) n = 10 boys: 11.70 ± 0.80 years n.a. 4.30 ± 1.40 25 m 50 m and 100 m Freestyle n.a.
Kjendlie and Stallman (2008) n = 9 boys: 11.70 ± 0.80 years n.a. n.a. 25 m 25 m Freestyle trial n.a.
Lätt et al. (2009a) n = 29 boys: 13.0 ± 1.80 years 2.30 ± 1.00 3.00 ± 1.10 25 m 400 m Freestyle n.a.
Lätt et al. (2009b) n = 26 girls: 12.70 ± 2.20 years 2.30 ± 0.80 3.70 ± 1.00 25 m 400 m Freestyle n.a.
Majid et al. (2019) n = 4 boys: 11.15 ± 0.96 years n.a. n.a. 50 m 50 m Breaststroke n.a.
Marinho et al. (2011) n = 12 boys and 8 girls: 12.10 ± 0.72 years n.a. 3.70 ± 1.26 n.a. 50 m, 100 m, and 200 m Freestyle, Backstroke, Breaststroke,
and
Butterfly
n.a.
Marinho et al. (2020) n = 75 boys and 76 girls: 13.02 ± 1.19 years n.a. 3.36 ± 0.77 years 25 m 100 m Freestyle n.a.
Mezzaroba and Machado (2014) n = 13 boys: 10.70 ± 0.90 years; n = 11 boys: 13.00 ± 0.50 years 2.20 ± 0.80 and 3.60 ± 0.80 3.50 ± 1.90 and 5.70 ± 3.30 years 50 m 100 m, 200 m, and 400 m Freestyle n.a.
Morais et al. (2012) n = 73 boys: 12.72 ± 1.03 years; 64 girls: 11.47 ± 0.66 years 1–2 n.a. 25 m 100 m Freestyle n.a.
Morais et al. (2013a) n = 62 boys: 12.76 ± 0.72 years; 64 girls: 11.89 ± 0.93 years 1–2 n.a. 25 m 100 m Freestyle n.a.
Morais et al. (2013b) n = 15 boys: 12.30 ± 0.63 years; 18 girls: 11.77 ± 0.92 years 1–2 3.18 ± 0.52 years 25 m 100 m Freestyle n.a.
Morais et al. (2014a) n = 14 boys: 12.33 ± 0.65 years; 16 girls: 11.15 ± 0.55 years 1–2 3.40 ± 0.56 years 25 m 100 m Freestyle Boys: 284.85 ± 67.48
Girls: 322.56 ± 45.18
Morais et al. (2014b) n = 14 boys, 7 high skill: 12.83 ± 0.37 years, 7 average skill: 11.83 ± 0.37 years; 16 girls, 8 high skill: 11.42 ± 0.49 years, 8 average skill: 10.83 ± 0.37 years 1–2 3.40 ± 0.56 years 25 m 100 m Freestyle Boys (high skill: 294.40 ± 40.00; average skill: 166.20 ± 17.50)
Girls (high skill: 334.30 ± 39.50;
average skill:
229.10 ± 33.90
Morais et al. (2015) n = 15 boys: 12.30 ± 0.60 years; 18 girls: 11.70 ± 0.90 years 1–2 3.18 ± 0.52 years 25 m 100 m Freestyle Boys: 227.90 ± 69.80
Girls: 291.10 ± 66.20
Morais et al. (2016) n = 49 boys: 12.50 ± 0.76 years; 51 girls: 12.20 ± 0.71 years 1–2 3.10 ± 0.71 years 25 m 100 m Freestyle n.a.
Morais et al. (2017) n = 47 boys: 12.04 ± 0.81 years; 47 girls: 11.22 ± 0.98 years n.a. 3.18 ± 0.62 years 25 m 100 m Freestyle Boys: 217.70 ± 69.50
Girls: 277.70 ± 68.70
Morais et al. (2020a) n = 22 boys: 12.79 ± 0.71 years; 32 girls: 11.78 ± 0.85 years 1–2 n.a. 25 m 100 m Freestyle Boys: 297.58 ± 87.72
Girls: 330.35 ± 79.80
Morais et al. (2020b) n = 14 boys: 12.70 ± 0.63 years; 16 girls: 11.72 ± 0.71 years 1–2 n.a. 25 m 100 m Freestyle Boys: 234.86 ± 69.76
Girls: 288.75 ± 67.01
Moreira et al. (2014) n = 12 boys: 12.80 ± 0.90 years; 13 girls: 12.00 ± 0.90 years 1–2 3.18 ± 0.52 years n.a. 25 m Freestyle trial n.a.
Nevill et al. (2020) n = n = 39 boys: 11.50 ± 1.30 years; n = 20 girls: 12.10 ± 1.00 years; n = 13.00 ± 1.00 years 2.33 ± 1.10, 0.04 ± 1.00, 0.82 ± 0.96 maturity offset years n.a. n.a. 100 m Breaststroke and Backstroke n.a.
Ozeker et al. (2020) n = 15 girls: 11.18 ± 0.80 years; n = 15 girls: 11.16 ± 0.83 years n.a. At least 3 years 50 m 50 m and 400 m Freestyle n.a.
Poujade et al. (2003) n = 3 girls and 8 boys: 12.40 ± 0.50 years n.a. 4–5 years 50 m 400 m Freestyle n.a.
Poujade et al. (2002) n = 3 girls and 8 boys: 12.40 ± 0.50 years n.a. 5–6 years n.a. 400 m Freestyle n.a.
Saavedra et al. (2013) n = 67 girls: 11.51 ± 0.55 years n.a. n.a. n.a. Best score according to the LEN table of competitive performance level n.a.
Saavedra et al. (2010) n = 67 girls: 11.50 ± 0.60 years 2.99 ± 1.19 n.a. 25 m Fastest of three competitive events swum in one of the four strokesat any of four different race distances (i.e., 100 m, 200 m, 400 m, and 800 m) n.a.
Sammoud et al. (2018) n = 39 boys: 11.50 ± 1.30 years; 20 girls: 12.00 ± 1.00 years Boys: −2.30 ± 1.10; girls: 0.04 ± 1.00 maturity offset years n.a. 25 m 100 m Breaststroke n.a.
Sammoud et al. (2019) (n = 26 boys) two groups: 10.30 ± 0.40 and 10.50 ± 0.40 years −3.10 ± 0.30 and −2.80 ± 0.30 years until peak height velocity 2.00 ± 1.60 years 50 m 15 m, 25 m, and 50 m Freestyle trial n.a.
Sammoud et al. (2021) (n = 22girls) two groups: 10.01 ± 0.57 and 10.50 ± 0.28 years −1.50 ± 0.50 and −1.34 ± 0.51 maturity offset 2.00 ± 1.40 years 50 m 25 m, and 50 m Freestyle trial n.a.
Seffrin et al. (2021) n = 16 boys: 11.50 ± 0.52 years; 6 girls: 11.67 ± 0.52 years n.a. n.a. n.a. 100 m and 400 m Freestyle n.a.
Silva et al. (2012) (n = 36 boys: 12.42 ± 0.08 years; and 24 girls: 11.08 ± 0.08 years) Boys: 2–3
Girls: 2–3
3.75 ± 0.87 and 3.38 ± 0.77 years n.a. 25 m Backstroke trial n.a.
Silva et al. (2013) Pubertal: n = 36 boys: 12.42 ± 0.08 years; 24 girls: 11.08 ± 0.08 years Post-pubertal: n = 20 boys: 12.65 ± 0.11 years; 34 girls: 11.71 ± 0.08 years Pubertal: 1–2
Post-pubertal: 3–5
Pubertal boys: 3.75 ± 0.87 years; girls: 3.38 ± 0.77 years Post-pubertal boys: 3.75 ± 1.25 years; girls: 3.35 ± 1.07 years n.a. 25 m Freestyle trial n.a.
Staub et al. (2020b) n = 952 boys and 936 girls: 11 years n.a. n.a. 50 m, 100 m, 200 m, 400 m Freestyle; 50 m, 100 m, 200 m Breaststroke and Backstroke; 50 m and 100 m Butterfly; 200 Individual Medley Swimmers ranked at 18 years: 321.90 ± 75.20
Swimmers not ranked at 18 years: 313.80 ± 73.70
Staub et al. (2020a) n = 842 boys and 863 girls: 11 years n.a. n.a. 50 m, 100 m, 200 m, and 400 m Freestyle; 50 m, 100 m, and 200 m for both Breaststroke and Backstroke; 50 m, and 100 m Butterfly; 200 m Individual Medley Relationships between success at age 18 (1–1000 FINA points), to within-sport specialization and age of entry
Tijani et al. (2019) n = 22 boys and 18 girls12.30 ± 0.56 years n.a. 7.10 ± 0.50 years 25 m 50 m Freestyle n.a.
Tsalis et al. (2012) n = 8 girls: 10.40 ± 0.60 years n.a. n.a. 50 m 50 m, 100 m, 200 m, and 400 m Freestyle n.a.
Zarzeczny et al. (2013) n = 24 boys: 12.20 ± 0.10 years n.a. n.a. 25 m 50 m, and 400 m Freestyle and Breaststroke n.a.

n.a., not applicable (i.e., not reported).