PMID- 31835963
OWN - NLM
STAT- MEDLINE
DCOM- 20200224
LR  - 20200224
IS  - 1466-447X (Electronic)
IS  - 0264-0414 (Linking)
VI  - 38
IP  - 4
DP  - 2020 Feb
TI  - Carbohydrate intake and ketosis in self-sufficient multi-stage ultramarathon 
      runners.
PG  - 366-374
LID - 10.1080/02640414.2019.1702269 [doi]
AB  - Ultra-endurance athletes accumulate an energy deficit throughout their events and 
      those competing in self-sufficient multi-stage races are particularly vulnerable 
      due to load carriage considerations. Whilst urinary ketones have previously been 
      noted in ultra-endurance exercise and attributed to insufficient carbohydrate 
      (CHO) availability, not all studies have reported concomitant CHO intake. Our aim 
      was to determine changes in blood glucose and beta-hydroxybutyrate concentrations 
      over five days (240 km) of a self-sufficient multi-stage ultramarathon in 
      combination with quantification of energy and macronutrient intakes, estimated 
      energy expenditure and evaluation of energy balance. Thirteen runners (8 male, 5 
      female, mean age 40 +/- 8 years) participated in the study. Glucose and 
      beta-hydroxybutyrate were measured every day immediately post-running, and food 
      diaries completed daily. CHO intakes of 301 +/- 106 g.day(-1) 
      (4.3 +/- 1.8 g.kg(-1).day(-1)) were not sufficient to avoid ketosis (5-day mean 
      beta-hydroxybutyrate: 1.1 +/- 0.6 mmol.L(-1)). Furthermore, ketosis was not attenuated 
      even when CHO intake was high (9 g.kg(-1).day(-1)). This suggests that competing 
      in a state of ketosis may be inevitable during multi-stage events where load 
      reduction is prioritised over energy provisions. Attenuating negative impacts 
      associated with such a metabolic shift in athletes unaccustomed to CHO and energy 
      restriction requires further exploration.
FAU - Edwards, Kate H
AU  - Edwards KH
AUID- ORCID: 0000-0003-2481-7501
AD  - Translational Physiology Research Group, School of Life Sciences, University of 
      Westminster, London, UK.
AD  - Sports Performance Optimisation Research Team, School of Health Sciences, 
      University of Tasmania, Launceston, Australia.
FAU - Elliott, Bradley T
AU  - Elliott BT
AUID- ORCID: 0000-0003-4295-3785
AD  - Translational Physiology Research Group, School of Life Sciences, University of 
      Westminster, London, UK.
FAU - Kitic, Cecilia M
AU  - Kitic CM
AUID- ORCID: 0000-0001-9866-5665
AD  - Sports Performance Optimisation Research Team, School of Health Sciences, 
      University of Tasmania, Launceston, Australia.
LA  - eng
PT  - Journal Article
DEP - 20191213
PL  - England
TA  - J Sports Sci
JT  - Journal of sports sciences
JID - 8405364
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
RN  - TZP1275679 (3-Hydroxybutyric Acid)
SB  - IM
MH  - 3-Hydroxybutyric Acid/*blood
MH  - Adult
MH  - Blood Glucose/*metabolism
MH  - Diet Records
MH  - Dietary Carbohydrates/*administration & dosage
MH  - *Energy Intake
MH  - Energy Metabolism/physiology
MH  - Female
MH  - Humans
MH  - Ketosis/*physiopathology
MH  - Male
MH  - Middle Aged
MH  - Physical Endurance/*physiology
MH  - Running/*physiology
MH  - Weight-Bearing
OTO - NOTNLM
OT  - Ketones
OT  - carbohydrate
OT  - energy deficit
OT  - nutrition
OT  - performance
OT  - running
OT  - ultra-endurance
EDAT- 2019/12/15 06:00
MHDA- 2020/02/25 06:00
CRDT- 2019/12/15 06:00
PHST- 2019/12/15 06:00 [pubmed]
PHST- 2020/02/25 06:00 [medline]
PHST- 2019/12/15 06:00 [entrez]
AID - 10.1080/02640414.2019.1702269 [doi]
PST - ppublish
SO  - J Sports Sci. 2020 Feb;38(4):366-374. doi: 10.1080/02640414.2019.1702269. Epub 
      2019 Dec 13.