The Effects Of One-week Exogenous Ketone Consumption On Short Distance Time Trial Running Performance

Abstract

Currently, there is equivocal knowledge concerning the effects of ketone salt supplementation on short distance running time trial (TT) performance in well-trained subjects. PURPOSE: To determine the effects of one-week exogenous ketone salt supplementation on 800m running TT performance during non-fatigued and pre-exhaustive states in endurance-trained subjects. METHODS: In a randomized, double-blind, placebo-controlled 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=16) or placebo control (CON) (n=16). Subjects underwent two consecutive 800m TT before and after the 8-day treatment period on a self-propelled, non-motorized treadmill. Time-to-completion of the first (TT1) and second (TT2) TTs, the average time-to-completion across both TTs, and blood lactate response during the TTs were measured pre- and post-treatment. A mixed factorial ANOVA was used for data analysis. RESULTS: KET alone exhibited a significant increase in blood β-hydroxybutyrate from pre-post-treatment (p<0.05). A group x time interaction was only detected for TT2 performance (p<0.05) but not TT1. There was no pre- to post-treatment change in TT1 performance in either group. CON demonstrated no change in TT2 performance from pre- to post-treatment; however, KET improved TT2 performance as reflected by a 3.7% faster time-to-completion from pre- to post-treatment (p<0.05). When examining the average time-to-completion across both TTs, there was a significant group x time interaction (p=0.04). CON showed no change while KET demonstrated a faster average time-to-completion from pre- to post-treatment (p<0.05). Blood lactate response to TTs decreased (p<0.05) in KET but not CON. CONCLUSIONS: In endurance-trained subjects, ketone salt supplementation does not appear to affect short-distance running TT performance in a non-fatigued state reflective of competition scenarios. However, ergogenic effects may be observed in high-intensity exercise when some level of exhaustion or energy substrate depletion is experienced prior, such as during training or prolonged, intermittently high-intensity sporting bouts.