164 Chapter 7 compared to lower-performing peers throughout puberty. Furthermore, they exhibited significantly higher levels of stroke index (SI), a measure of technical ability (males aged 12-14, females aged 12), with significantly faster advancements for high-performing late junior males in this aspect as well (+7% in males). Shifting our focus to the land-based tests, we found that high-performing late junior females were significantly taller at age 13 and 14, and demonstrated higher CMJ at age 14 compared to lower-performing peers, whereas surprisingly, no significant between-group differences were found for males on these variables. Taken together, swimmers who are on track to the elite level at late junior age (males aged 16; females aged 15) are characterized with the ability to attain higher swimming speed with equal (females aged 13-14) or even better levels of technical efficiency than lower-performing juniors throughout puberty. Given that competitive swimming centers around maintaining optimal power output in an efficient and skillful manner throughout the event (Miyashita, 1996), this could be a critical factor in the attainment of swimming expertise. Additionally, being taller, particularly as a female aged 13-14, may be a beneficial characteristic for superior swim performances post-puberty. This advantage can be attributed to the strong relationship between longer lengths, such as height, and increased stroke length and speed (Morais et al., 2021). Maturation and training Considering our findings, it is important to acknowledge that performance and its underlying performance characteristics may be influenced by inter-individual differences in timing of PHV as well as training hours. Regarding the former, we found a significantly earlier onset of PHV in high performing late junior females (~2.4 months) as well as within-group variations of 1.0 to 1.5 years in age of PHV (females and males respectively). While we cannot disregard the possibility that relatively early maturing swimmers in our study may have experienced physical advantages compared to relatively later maturing swimmers, we do not expect that these variations significantly affected our findings. This anticipation is grounded in the observation that the between- and within-group differences are considerably small, particularly compared to the five to six years difference between players’ chronological and biological age reported by Johnson et al. (2009). In the context of training, we observed that high-performing late junior swimmers tend to engage in slightly more swim training hours per week, with this trend being more pronounced among males compared to females. Interestingly, the minimum training hours per week are consistently higher among high-performing late juniors. Within performance level groups , we noticed differences of more than ten hours between swimmers who had the lowest and highest amount of swim training per week. Given that the total amount of (deliberate) training is correlated with attainment (Baker & Young 2014), it is likely that such notable differences may advantaged swimmers with access to a higher number of
RkJQdWJsaXNoZXIy MTk4NDMw