Relationship of changes in strength and power characteristics to swimming start performance.

Abstract

The overall aim of this thesis was to describe the strength and power characteristics required for swim start performance, and the effects of dry-land resistance training on the swim start. To achieve this, the thesis was broken into five research chapters. The first study (Chapter 3) reviewed the current literature on the acute relationship between dry-land physical performance measures and swim start performance along with the acute and chronic effects of dry-land resistance training on swim start performance. A range of strength and power exercises were highly correlated to swim start performance, especially when utilising body weight vertical jumping exercises such as countermovement (CMJ) and squat jump (SJ) (r > 0.90). A variety of resistance training approaches were also found to significantly improve swim start performance, especially when these programs included plyometric and non-plyometric jumps. The second study (Chapter 4) developed a multiple regression model to determine the most important SJ force-time predictors for swim start times to 5 m and 15 m in high performance male and female swimmers. Concentric impulse was identified as a key lower body force-time characteristic to start times to 5 m and 15 m in both sexes, with Reactive strength index modified and concentric mean power also contributing to start performance in female swimmers. The third study (Chapter 5) sought to identify which block outcome kinetic measures have the greatest relationship to 15 m start time and to understand the direction and temporal sequencing of forces in the block phase. Linear mixed modelling identified four on-block outcome kinetic variables (work, average power, horizontal take-off velocity, and average acceleration) as having a very large relationship (R2 = 0.79 - 0.83) to 15 m start time. On-block force sequencing started with the rear leg, followed by upper limb grab forces and the front leg. The fourth study (Chapter 6) compared the effects of an 8-week horizontal- (HF) and vertical-force (VF) oriented emphasis resistance training program on swim start performance (HF: n = 6; VF: n = 5). While seven moderate between-group effect size differences were observed, no significant between-group differences were observed between the HF and VF groups in predicted one repetition maximum strength, SJ force-time characteristics, and swim start performance measures post-intervention. The final study (Chapter 7) was a case series that involved longitudinal monitoring of body composition, SJ force-time characteristics and swim start performance over a competitive season (with three assessment time points over ~12 months) in five high performance swimmers. Repeated measures correlation analyses indicated a number of significant interactions between physical and technical components that can influence a swimmer’s start performance in both the flight and in-water phases. However, changes in swim start performance and the other variables assessed were quite individual. In summary, the results of this thesis have increased our understanding of the determinants of swim start performance in high performance swimmers. These findings may have relevance for how strength and conditioning coaches and sports science practitioners can best contribute to improving swim start performance in high performance swimmers.

Date of Award	16 Jun 2021
Original language	English
Supervisor	Justin Keogh (Supervisor), Peter Reaburn (Supervisor) & Simon Pearson (Supervisor)