Practical Precooling Strategies and Cycling Time Trial Performance
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Edith Cowan University Research Online Theses: Doctorates and Masters Theses 2012 Practical precooling strategies and cycling time trial performance Megan L. Ross Edith Cowan University Follow this and additional works at: https://ro.ecu.edu.au/theses Part of the Sports Sciences Commons Recommended Citation Ross, M. L. (2012). Practical precooling strategies and cycling time trial performance. https://ro.ecu.edu.au/theses/511 This Thesis is posted at Research Online. https://ro.ecu.edu.au/theses/511 Edith Cowan University Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorize you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. You are reminded of the following: Copyright owners are entitled to take legal action against persons who infringe their copyright. A reproduction of material that is protected by copyright may be a copyright infringement. Where the reproduction of such material is done without attribution of authorship, with false attribution of authorship or the authorship is treated in a derogatory manner, this may be a breach of the author’s moral rights contained in Part IX of the Copyright Act 1968 (Cth). Courts have the power to impose a wide range of civil and criminal sanctions for infringement of copyright, infringement of moral rights and other offences under the Copyright Act 1968 (Cth). Higher penalties may apply, and higher damages may be awarded, for offences and infringements involving the conversion of material into digital or electronic form. EDITH COWAN UNIVERSITY School of Exercise and Health Sciences Practical Precooling Strategies and Cycling Time Trial Performance By Megan L.R. Ross B.App.Sci (Hons) This thesis is presented for the award of Doctor of Philosophy (Sports Science) from the School of Exercise and Health Sciences; Faculty of Computing, Health and Science; Edith Cowan University, Western Australia Principal Supervisor: Adjunct Professor Paul B. Laursen (Edith Cowan University) Co-supervisor: Dr. Chris R. Abbiss (Edith Cowan University) Industry Supervisor: Professor Louise M. Burke (Australian Institute of Sport) Co-supervisor: Dr. David T. Martin (Australian Institute of Sport) Date of Submission: 6th November 2012 DECLARATION I certify that this thesis does not, to the best of my knowledge and belief: i. incorporate without acknowledgement any material previously submitted for a degree or diploma in any institution of higher education; ii. contain any material previously published or written by another person except where due reference is made in the text; or iii. contain any defamatory material I also grant permission for the Library at Edith Cowan University to make duplicate copies of my thesis as required. Signature: Date: 6th November 2012 i This page has been left intentially blank ii USE OF THESIS The Use of Thesis statement is not included in this version of the thesis. This thesis is dedicated to the loves of my life, my husband Jeremy and our darling little boy, Archie In loving memory of Harvey Francis Jones 16.3.1946 – 22.12.2009 iv ACKNOWLEDGMENTS This project was upheld by the commitment and enthusiasm of many people and it is a pleasure to thank them for their contribution making this thesis possible. I am truly indebted to each of you for enriching my scientific development and believing in me. First and foremostly, I would like to offer my sincerest gratitude to my supervisor; captain of the A-Team, Professor Louise M. Burke. Your enthusiasm for this project and your enduring dedication to my development are qualities I admire and really appreciate. Thank you for teaching me your craft and sharing with me your knowledge. Your involvement has certainly made this journey a pleasurable experience. I am grateful to you for entrusting me with this project and for allocating funding - won by the Australian Institute of Sport (AIS), Sports Nutrition discipline - which was provided by Nestle Australia and the AIS Performance Research Centre. I am also very privileged to have had Dr. Chris R. Abbiss as a co-supervisor and friend. I wish to thank you for giving me direction and keeping me on the right track. Your calm and measured approach motivated me and gave me a powerful sense of confidence that I could actually achieve such an accomplishment. I am especially grateful to my co-supervisors, Dr. David T. Martin and Adjunct Professor Paul B. Laursen, for your ingenious ideas. Your enthusiasm and motivation is infectious and has played a large part in encouraging me to complete this journey with a smile on my face. v I was also extremely fortunate to have the experience and fastidiousness of Nikki Jeacocke in preparing standardised diets for all subjects with such precision. Thank you for doing such an excellent job and the sharing of the journey across various projects conducted during the past six years! The significant technical assistance of Mr. Jamie Plowman, Mr. Michael Steinebronn, Mr. Nathan Versey, Miss Laura Juliff and Miss Anna Neumaier are gratefully acknowledged. I would also like to thank Dr. Susan Shirreffs and Dr. Matt Brearley, for sharing their ideas and practical strategies for overcoming hurdles in the very early phase of this project. I am forever grateful to Shona Halson, for your professional guidance and giving me a career opportunity that was once a dream - London 2012. I trust that the future will uphold a typical theme of ours, which always involves a great deal of fun. I cherish my friendship with Sally Clark - one that has developed over many coffees and long walks. I am truly grateful for the wealth of professional and personal advice you offer me. To Laura Garvican for simply being a great friend. Thanks for understanding and providing options with your uncanny ability to make logical sense. But more importantly for sharing our mutually pleasurable hobby together - tea-drinking. To my friends outside of the research and sporting worlds, thank you for giving me perspective, especially to Amy Agar and Alison McMahon, when things didn’t quite go to plan and for looking after me in Singapore. I am also indebted to Donna and Mark Holland, for keeping me entertained with your hilarious and unbelievable stories, and enabling me to survive living in Bandung, Indonesia for a short spell. vi To Judy, Geoff, Alison, Simon and Caroline and your growing families, sincere thanks for your understanding, enduring support and love. Thank you David & Yemee, and Huwy & Penny for your encouragement, enthusiasm and understanding throughout my Ph.D., but especially for showing me the lighter side. I must make a very special mention of my mum, Hede. You have always given me unwavering support in the challenges I have set out to achieve, and the confidence to take my own path. Amongst your many other amiable qualities, you have taught me to work hard and persevere; skills that were tested, but extremely useful during the completion of this thesis. Sincere thanks for everything you do for me and for the decisions you and dad made along the way. I am very fortunate to be cared for and loved by you. Penultimately, to Archie; without you this thesis may have been submitted slightly sooner but I couldn’t have written it without you. For you have made me a more grounded person and for which this thesis is better off. Thank you for the wonderful journey so far and teaching me to keep on trying. Most importantly, to Jem, for your incredible patience, encouragement and support that has enabled me to finish this thesis. I love you dearly. You have lived through every challenge and milestone involved in the writing of this thesis and I am eternally grateful to you for taking the journey with me. Your curiosity for life is alluring and thank you for sharing it with me. Thanks also for the most bizarre of things; taking me to the bookstore in Chapel Street all those years ago, encouraging me to leave my dream job to move to Canberra and digging such a big vii hole so we could plant our first tree together. Thank you for encouraging me to get out for a run, making me laugh and challenging me to be a better person. I can now say, it is the end of this particular journey. A great poet, patriot and martyr of Cuban Independence, José Martí (1853-1895) stated simply that in order to have lived a complete life, a person must ‘plant a tree, have a son, write a book’. I am extremely fortunate to have achieved these three things in order, during the completion of this thesis. viii ABSTRACT Whole-body precooling can improve endurance exercise performance, especially in the heat; however there are logistical considerations that restrict the use of various precooling strategies prior to actual competition. Precooling is proposed to collectively reduce deep skin and body temperature and in effect, increase the heat storage capacity of an athlete, thereby allowing a greater amount of work to be completed prior to attainment of a critical core temperature. While there is a sound theoretical basis for implementing precooling to improve cycling time trial performance in the heat, the practicalities of employing effective precooling strategies in the field warrant further investigation. The purpose of this thesis was to investigate the effectiveness of various practical precooling strategies for reducing core temperature and improving cycling time trial performance in hot (32-35ºC; 50-60% r.h.) and temperate (20-22 ºC; 50-60% r.h.) conditions. The first three studies of this thesis involved the manipulation of body temperature via a range of precooling strategies that were applied under hot and humid environmental conditions.