Author(s): LJØDAL, I., WORTELBOER, M.W., GONJO, T., OLSTAD, B.H., Institution: NORWEGIAN SCHOOL OF SPORT SCIENCES AND UNIVERSITY OF ROUEN, Country: NORWAY, Abstract-ID: 2421

INTRODUCTION:
Compared with actual performance, load-velocity profiles have proven to be good predictors of swimming performance in front crawl (Gonjo et al., 2021). The use of load-velocity testing remains underexplored in adolescent populations, only one age-group comparison of girls (Wettengl et al., 2024). The application of this method within an adolescent age group, from amateur to elite, can provide valuable insight into the development of swimming performance among adolescents who are currently in their early developmental stages of puberty.
METHODS:
This was a cross-sectional study within a longitudinal study, including 113 male and female swimmers (age 12.28 ± 0.46 y, height 159.11 ± 7.51 cm and weight 47.91 ± 7.90 kg). The 50-meter race was recorded using the AIM race analysis system (AIMsys Sweden AB, Lund, Sweden). Swimming velocity (V50m) excluded the first and last stroke on each lap. The data for the load-velocity profiles was collected using 1080 Sprint (1080 Motion, Lidingö, Sweden). Participants performed three semi-tethered 25 m swims with progressively increasing loads (~ 1 - 2 - 3 kg) in front crawl with maximum effort. A 5 m range between 10 m and 15 m from the wall was used to calculate the average swimming velocity of the semi-tethered swimming and a regression line predicted the maximum swimming velocity (Vmax). The Shapiro-Wilk test was used to check the data distribution. One-way ANOVA (parametric data) and the Kruskal-Wallis test (non-parametric) were used to analyse the differences between boys and girls. Pearson’s correlation coefficient was used to analyse covariation.
RESULTS:
There were significant differences between male and female swimmers in time in seconds for 50 m (T50m, males 34.83 ± 3.67 s, females 36.41 ± 3.27 s, p < 0.027), V50m (males 1.37 ± 0.14 m/s, females 1.29 ± 0.12 m/s, p < 0.005), and Vmax (males 1.25 ± 0.18 m/s, females 1.17 ± 0.15 m/s, p < 0.010). The correlation between T50m and Vmax was r = 0.459, p < 0.001.
CONCLUSION:
The differences found for T50m, V50m, and Vmax show that boys have a faster swimming time, a higher swimming velocity, and a higher estimated maximum velocity based on the load-velocity profile. This suggests that the pubertal change in body composition is progressed enough to show the physical benefits for male swimmers at this age. The moderate correlation between T50m and Vmax also supports the use of load-velocity testing for predicting performance in young adolescent swimmers.

Gonjo, T., Njøs, N., Eriksrud, O., & Olstad, B. H. (2021). The relationship between selected load-velocity profile parameters and 50 m front crawl swimming performance. Frontiers in Physiology, 12, 625411. https://doi.org/10.3389/fphys.2021.625411
Wettengl, C., Karlsson, R., Olstad, B. H., & Gonjo, T. (2024). Load–Velocity Profile and Active Drag in Young Female Swimmers: An Age-Group Comparison. International Journal of Sports Physiology and Performance, 19(1), 44-52. https://doi.org/10.1123/ijspp.2022-0213