PMID- 25811132
OWN - NLM
STAT- MEDLINE
DCOM- 20160808
LR  - 20151102
IS  - 1543-2742 (Electronic)
IS  - 1526-484X (Linking)
VI  - 25
IP  - 5
DP  - 2015 Oct
TI  - Manipulating Carbohydrate Availability Between Twice-Daily Sessions of 
      High-Intensity Interval Training Over 2 Weeks Improves Time-Trial Performance.
PG  - 463-70
LID - 10.1123/ijsnem.2014-0263 [doi]
AB  - Commencing some training sessions with reduced carbohydrate (CHO) availability 
      has been shown to enhance skeletal muscle adaptations, but the effect on exercise 
      performance is less clear. We examined whether restricting CHO intake between 
      twice daily sessions of high-intensity interval training (HIIT) augments 
      improvements in exercise performance and mitochondrial content. Eighteen active 
      but not highly trained subjects (peak oxygen uptake [VO2peak] = 44 +/- 9 
      ml/kg/min), matched for age, sex, and fitness, were randomly allocated to two 
      groups. On each of 6 days over 2 weeks, subjects completed two training sessions, 
      each consisting of 5 x 4-min cycling intervals (60% of peak power), interspersed 
      by 2 min of recovery. Subjects ingested either 195 g of CHO (HI-HI group: ~2.3 
      g/kg) or 17 g of CHO (HI-LO group: ~0.3 g/kg) during the 3-hr period between 
      sessions. The training-induced improvement in 250-kJ time trial performance was 
      greater (p = .02) in the HI-LO group (211 +/- 66 W to 244 +/- 75 W) compared with the 
      HI-HI group (203 +/- 53 W to 219 +/- 60 W); however, the increases in mitochondrial 
      content was similar between groups, as reflected by similar increases in citrate 
      synthase maximal activity, citrate synthase protein content and cytochrome c 
      oxidase subunit IV protein content (p > .05 for interaction terms). This is the 
      first study to show that a short-term "train low, compete high" intervention can 
      improve whole-body exercise capacity. Further research is needed to determine 
      whether this type of manipulation can also enhance performance in highly-trained 
      subjects.
FAU - Cochran, Andrew J
AU  - Cochran AJ
AD  - Exercise Metabolism Research Group, Department of Kinesiology, McMaster 
      University, Hamilton, Ontario, Canada.
FAU - Myslik, Frank
AU  - Myslik F
FAU - MacInnis, Martin J
AU  - MacInnis MJ
FAU - Percival, Michael E
AU  - Percival ME
FAU - Bishop, David
AU  - Bishop D
FAU - Tarnopolsky, Mark A
AU  - Tarnopolsky MA
FAU - Gibala, Martin J
AU  - Gibala MJ
LA  - eng
PT  - Clinical Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20150326
PL  - United States
TA  - Int J Sport Nutr Exerc Metab
JT  - International journal of sport nutrition and exercise metabolism
JID - 100939812
RN  - 0 (Dietary Carbohydrates)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
RN  - EC 2.3.3.1 (Citrate (si)-Synthase)
SB  - IM
MH  - Adaptation, Physiological/*drug effects
MH  - Athletic Performance/*physiology
MH  - Citrate (si)-Synthase/metabolism
MH  - Dietary Carbohydrates/*administration & dosage
MH  - Electron Transport Complex IV/metabolism
MH  - Energy Metabolism
MH  - Exercise Test/drug effects
MH  - Female
MH  - Humans
MH  - Male
MH  - Mitochondria, Muscle/enzymology
MH  - Oxygen Consumption
MH  - Random Allocation
MH  - Sports Nutritional Physiological Phenomena/*drug effects
MH  - Time Factors
MH  - Young Adult
EDAT- 2015/03/27 06:00
MHDA- 2016/08/09 06:00
CRDT- 2015/03/27 06:00
PHST- 2015/03/27 06:00 [entrez]
PHST- 2015/03/27 06:00 [pubmed]
PHST- 2016/08/09 06:00 [medline]
AID - 2014-0263 [pii]
AID - 10.1123/ijsnem.2014-0263 [doi]
PST - ppublish
SO  - Int J Sport Nutr Exerc Metab. 2015 Oct;25(5):463-70. doi: 
      10.1123/ijsnem.2014-0263. Epub 2015 Mar 26.