PMID- 29109686
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220409
IS  - 1664-042X (Print)
IS  - 1664-042X (Electronic)
IS  - 1664-042X (Linking)
VI  - 8
DP  - 2017
TI  - Ketone Diester Ingestion Impairs Time-Trial Performance in Professional Cyclists.
PG  - 806
LID - 10.3389/fphys.2017.00806 [doi]
LID - 806
AB  - 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 beta-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.
FAU - Leckey, Jill J
AU  - Leckey JJ
AD  - Centre for Exercise and Nutrition, Mary MacKillop Institute for Health Research, 
      Australian Catholic University, Melbourne, VIC, Australia.
FAU - Ross, Megan L
AU  - Ross ML
AD  - Centre for Exercise and Nutrition, Mary MacKillop Institute for Health Research, 
      Australian Catholic University, Melbourne, VIC, Australia.
AD  - Sports Nutrition, Australian Institute of Sport, Canberra, ACT, Australia.
FAU - Quod, Marc
AU  - Quod M
AD  - ORICA-BikeExchange (WorldTour Team), UCI, Adelaide, SA, Australia.
FAU - Hawley, John A
AU  - Hawley JA
AD  - Centre for Exercise and Nutrition, Mary MacKillop Institute for Health Research, 
      Australian Catholic University, Melbourne, VIC, Australia.
AD  - Research Institute for Sport and Exercise Sciences, Liverpool John Moores 
      University, Liverpool, United Kingdom.
FAU - Burke, Louise M
AU  - Burke LM
AD  - Centre for Exercise and Nutrition, Mary MacKillop Institute for Health Research, 
      Australian Catholic University, Melbourne, VIC, Australia.
AD  - Sports Nutrition, Australian Institute of Sport, Canberra, ACT, Australia.
LA  - eng
PT  - Journal Article
DEP - 20171023
PL  - Switzerland
TA  - Front Physiol
JT  - Frontiers in physiology
JID - 101549006
CIN - Front Physiol. 2018 Mar 27;9:279. PMID: 29637933
PMC - PMC5660098
OTO - NOTNLM
OT  - cycling
OT  - ketone ester
OT  - ketones
OT  - performance
OT  - time-trial
EDAT- 2017/11/08 06:00
MHDA- 2017/11/08 06:01
PMCR- 2017/10/23
CRDT- 2017/11/08 06:00
PHST- 2017/05/22 00:00 [received]
PHST- 2017/09/29 00:00 [accepted]
PHST- 2017/11/08 06:00 [entrez]
PHST- 2017/11/08 06:00 [pubmed]
PHST- 2017/11/08 06:01 [medline]
PHST- 2017/10/23 00:00 [pmc-release]
AID - 10.3389/fphys.2017.00806 [doi]
PST - epublish
SO  - Front Physiol. 2017 Oct 23;8:806. doi: 10.3389/fphys.2017.00806. eCollection 
      2017.