THE EFFECTS OF ONE-WEEK EXOGENOUS KETONE CONSUMPTION ON TIME TRIAL RUNNING PERFORMANCE A Thesis Presented to the Faculty of California State Polytechnic University, Pomona In Partial Fulfillment Of the Requirements for the Degree Master of Science In Kinesiology By Samantha C. Silva 2018 SIGNATURE PAGE THESIS: THE EFFECTS OF ONE-WEEK EXOGENOUS KETONE CONSUMPTION ON TIME TRIAL RUNNING PERFORMANCE AUTHOR: Samantha C. Silva DATE SUBMITTED: Spring 2018 Kinesiology and Health Promotion Department Dr. Edward Jo Thesis Committee Chair Kinesiology and Health Promotion Dr. Ken Hansen Kinesiology and Health Promotion Alexandra Auslander Kinesiology and Health Promotion ii ABSTRACT The rationale behind exogenous ketone supplementation is to shift energy substrate reliance, preserve intramuscular glycogen, and improve exercise or sport performance. Prior investigations have demonstrated the ergogenic efficacy of exogenous ketone supplementation, however less is known regarding the effects of a short-term ketone supplementation period on short-distance running time trial (TT) performance in highly-trained subjects. Thus, the purpose of this study was to determine the effects of one-week exogenous ketone salt supplementation on short-distance running TT performance in endurance-trained subjects. In a randomized, double-blind study, endurance-trained male and female participants were allocated to one of the following treatment groups for 8 days following an initial familiarization visit: Ketone supplementation (KET) (n=10) or placebo control (CON) (n=9). Subjects underwent two consecutive (laboratory-based) 800m TT before and after the 8-day treatment period. Both groups were tested for best and average time-to-completion and blood lactate response during TT performance pre- and post-treatment. There was a significant treatment x time interaction for best TT performance (i.e. fastest time to completion) (p=0.02). CON demonstrated no change in TT performance from pre- to post-treatment; however, KET improved TT performance as reflected by a 5.8±8.9% decrease in time to completion from pre- to post-treatment (p=0.02, 95%CI= 2.2, 25.2). When controlling for pre-treatment best TT performance, KET had a significantly faster TT than CON (p=0.03). When examining the average TT performance across the 2 consecutive trials, there was a significant group x time interaction (p=0.04). CON showed no change in average time to completion and KET demonstrated a significant decrease in time to iii completion from pre- to post-treatment (p=0.04, 95% CI= 0.40-17.2). When controlling for pre-treatment average TT, KET showed a faster TT than CON (p=0.04). Two-way ANOVA revealed no effect of sex on the pre- to post-treatment change in TT performance (i.e. both best and average performance). Overall, the results support the use of ketone salt supplements as an ergogenic aid for short-distance running performance in trained individuals. iv TABLE OF CONTENTS Signature Page .............................................................................................................. ii Abstract ......................................................................................................................... iii List of Figures .............................................................................................................. vi List of Tables ............................................................................................................... vii Chapter 1: Introduction ................................................................................................. 1 Statement of the Problem .................................................................................. 2 Purpose Statement ............................................................................................. 2 Significance of the Study .................................................................................. 2 Specific Aims .................................................................................................... 3 Hypothesis......................................................................................................... 3 Limitations ........................................................................................................ 3 Delimitations ..................................................................................................... 4 Operational Definitions ..................................................................................... 4 Chapter 2: Literature Review ........................................................................................ 5 Ketone Metabolism ........................................................................................... 5 Ketone Metabolism under Exercise .................................................................. 7 Exogenous Ketone Supplementation and Human Performance ....................... 9 Conclusion and Future Research Implications ................................................. 10 Chapter 3: Methodology ............................................................................................... 12 Experimental Design ......................................................................................... 12 Subjects ............................................................................................................. 13 Dietary Supplementation Protocol .................................................................... 14 iii Laboratory Testing Procedures ......................................................................... 14 Time Trial Testing Procedures.............................................................. 14 Physiological Status Monitor Procedures ............................................. 15 Blood Lactate Measurement ................................................................. 15 Exercise and Dietary Control ............................................................................ 16 Analysis of Data ................................................................................................ 16 Chapter Four: Results ................................................................................................... 18 Time Trial Performance and Blood Lactate Response ..................................... 17 Magnitude-Based Qualitative Inference Analysis ............................................ 20 Chapter Five: Discussion .............................................................................................. 22 References ..................................................................................................................... 29 iv LIST OF TABLES Table 1 Between-group comparison of descriptive measures ................................. 17 Table 2 Mean values for Pre- to Post-Treatment Change (∆) in Best and Average Time Trial (TT) Time to Completion and Lactate Response during TT .... 21 vi LIST OF FIGURES Figure 1 Ketone Metabolism ..................................................................................... 7 Figure 2 Schematic of Experimental Timeline .......................................................... 13 Figure 3 Pre- to Post-Treatment Change in Best and Average Time Trial Performance ................................................................................................ 19 Figure 4 Change in Blood Lactate from Rest to Post-TT .......................................... 20 vii CHAPTER ONE Introduction The optimization of exercise training and human performance has been a hallmark focus of exercise science research (Cox & Clarke, 2014; Cox et al., 2016; Egan & D'Agostino, 2016b; Evans, Cogan, & Egan, 2017; Zajac et al., 2014). Within this line of investigative literature, various ergogenic strategies have been explored, especially those pertaining to nutritional modifications. Recently, ketogenic diets have received increased attention with a concomitant level of scrutiny regarding its efficacy in enhancing endurance performance. The theory underlying the use of high-fat and low carbohydrate ketogenic diet programs by athletes involves the purported improvement in the use of lipids and ketone bodies as an energy substrate in efforts to preserve muscle glycogen (i.e. muscle “fuel”) during exercise or physical competition. However, prior research, such as Burke et al. (2017), Fleming et al. (2003), and Zajac et al. (2014), demonstrates its futility as results reported negative outcomes for performance or training adaptations. Ketogenic diets have shown to improve fat oxidation capacities and provide alternative energy substrates in the form of ketone bodies/ketones but ultimately rely on the depletion of muscle and hepatic glycogen which would counteract exercise performance (Evans et al., 2017; Laffel, 1999; Robinson & Williamson, 1980). Exogenous ketones, namely beta-hydroxybutyrate esters or salts, have recently been implicated as an alternate and perhaps more effective means of providing energy substrate support to aid in muscle glycogen preservation during exercise and thereby performance. A body of research, albeit limited, have demonstrated the efficacy by which ketone supplementation aids athletic performance through an integrative 1 mechanism of energy substrate provision and muscle glycogen preservation while also showing some therapeutic benefits (Cox & Clarke, 2014; Cox et al., 2016; Evans et al., 2017). What remains uncertain are the effects and applications of long-term or prolonged ketone salt supplementation on short-distance running performance,