Date of Award


Degree Type


Degree Name

Doctor of Philosophy


School of Medical and Health Sciences

First Advisor

Dr Jeremy Sheppard

Second Advisor

Dr Sophia Nimphius


The overall aim of this thesis was to increase strength and conditioning coaches, and sport scientists’ understanding of the lower-body muscle structures related to enhanced lower-body physical capacities, and how to best evoke desirable training-specific adaptations. To address this aim, three successive steps of research were evaluated: (1) analysis of the factors related to increased performance in competitive surfing, (2) relationships between lower-body muscle structures and factors associated with enhanced physical performance, and (3) comparison of the training-specific adaptations evoked from various training methods. Whilst this research specifically focused on competitive surfing athletes, these results may benefit the training practices of athletes from a wide range of sports. The comprehensive conclusion of the research studies in this thesis suggest that competitive surfing is highly reliant on lower-body force producing capabilities, with specific vastus lateralis and lateral gastrocnemius muscle structures significantly related to these lower-body physical performance capacities. Additionally, the separation of strength and, gymnastics and plyometric training may not be best practice for adolescent athletes. However, a short duration combined strength, plyometric and gymnastics training intervention appears to provide a significant stimulus to evoke desirable adaptations in lower-body muscle structure and physical performance capacities for athletes that have limited opportunities for training between major competitions. Therefore, this thesis has provided descriptive, predictive and determinant findings associated with the physical preparation of surfing athletes, and iii therefore, provides strength and conditioning coaches, and sport scientists with an enhanced understanding of how best to evoke desirable adaptations in lower-body muscle structure and physical performance capacities.


Chapters 2, 3, 4,5, & 6 are not included in this version of the thesis for Copyright reasons. The contents of these chapters were published as journal articles and listed under Related Publications.