Original Research ARTICLE
Ketone diester ingestion impairs time-trial performance in professional cyclists
- 1Mary MacKillop Instiute for Health Research, Australian Catholic University, Australia
- 2Sports Nutrition, Australian Institute of Sport, Australia
- 3ORICA-BikeExchange WorldTour Team, UCI, Australia
- 4Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, United Kingdom
We investigated the effect of pre- “race” ingestion of a 1,3-butanediol acetoacetate diester on blood ketone concentration, substrate metabolism and performance of a cycling time trial (TT) in professional cyclists. In a randomized cross-over design, 10 elite male cyclists completed a ~ 31 km laboratory-based TT on a cycling ergometer programmed to simulate the 2017 World Road Cycling Championships course. Cyclists consumed a standardized meal (2 g/kg body mass [BM] carbohydrate [CHO]) the evening prior to a trial day and a CHO breakfast (2 g/kg BM CHO) with 200 mg caffeine on the morning of a trial day. Cyclists were randomized to consume either the ketone diester (2 x 250 mg/kg) or a placebo drink, followed immediately by 200 mL diet cola, given ~ 30 min before and immediately prior to commencing a 20 min incremental warm-up. Blood samples were collected prior to and during the warm-up, pre- and post- TT and at regular intervals after the TT. Urine samples were collected pre- and post- warm-up, immediately post TT and 60 min post TT. Pre-exercise ingestion of the diester resulted in a 2 ± 1% impairment in TT performance that was associated with gut discomfort and higher perception of effort. Serum β- hydroxybutyrate, serum acetoacetate and urine ketone concentrations increased from rest following ketone ingestion and were higher than placebo throughout the trial. Ketone ingestion induces hyperketonemia in elite professional cyclists when in a carbohydrate fed state, and impairs performance of a cycling TT lasting ~50 min.
Keywords: Ketone ester, Cycling, time-trial, performance, Ketones
Received: 22 May 2017;
Accepted: 29 Sep 2017.
Edited by:Gregoire P. Millet, University of Lausanne, Switzerland
Reviewed by:Samuele M. Marcora, University of Kent, United Kingdom
Andrew Renfree, University of Worcester, United Kingdom
Copyright: © 2017 Leckey, Ross, Quod, Hawley and Burke. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Louise M. Burke, Mary MacKillop Instiute for Health Research, Australian Catholic University, 215 Spring Street, Melbourne, 3000, VIC, Australia, Louise.Burke@ausport.gov.au