PMID- 28902115
OWN - NLM
STAT- MEDLINE
DCOM- 20181026
LR  - 20181026
IS  - 1533-4287 (Electronic)
IS  - 1064-8011 (Linking)
VI  - 32
IP  - 8
DP  - 2018 Aug
TI  - Repeated High-Intensity Cycling Performance Is Unaffected by Timing of 
      Carbohydrate Ingestion.
PG  - 2243-2249
LID - 10.1519/JSC.0000000000002226 [doi]
AB  - Shei, R-J, Paris, HL, Beck, CP, Chapman, RF, and Mickleborough, TD. Repeated 
      high-intensity cycling performance is unaffected by timing of carbohydrate 
      ingestion. J Strength Cond Res 32(8): 2243-2249, 2018-To determine whether 
      carbohydrate (CHO) feeding taken immediately before, early, or late in a series 
      of high-intensity cycling exercises affected cycling performance. A total of 16 
      trained, male cyclists (>6 hours postprandial) performed 3-, 4-km cycling time 
      trials (TT1, TT2, and TT3) separated by 15 minutes of active recovery on 4 
      separate occasions. Carbohydrate feeding (80 g) was given either before TT1 
      (PRE1), before TT2 (PRE2), before TT3 (PRE3), or not at all (control, CTL). 
      Treatment order was randomized. Sweet placebo was given before the other TTs. 
      Blood glucose (BG) concentration was measured before each trial. Mean power 
      output (Pmean) and time to completion (TTC) were recorded. Pmean was higher in 
      TT1 compared with TT2 (p = 0.001) and TT3 (p = 0.004) in all conditions, but no 
      differences were observed between treatments. Time to completion was lower in TT1 
      compared with TT2 (p = 0.01), but no other differences in TTC (within or between 
      treatments) were observed. Within CTL and PRE1, BG did not differ between TT1, 
      TT2, and TT3. In PRE2, BG was significantly higher in TT2 compared with TT1 (p = 
      0.006), in TT3 compared with TT1 (p = 0.001), and in TT3 compared with TT2 (p = 
      0.01). In PRE3, BG was significantly higher in TT3 compared with TT1 and TT2 (p = 
      0.001 for both). Given that performance was not influenced by the timing of CHO 
      ingestion, athletes engaging in repeated, high-intensity cycling exercise do not 
      need to ingest CHO before- or between-exercise bouts; furthermore, athletes 
      should refrain from ingesting CHO between bouts if they wish to avoid a rise in 
      BG.
FAU - Shei, Ren-Jay
AU  - Shei RJ
AD  - HH Morris Human Performance and Exercise Biochemistry Laboratory, Department of 
      Kinesiology, School of Public Health-Bloomington, Indiana University, 
      Bloomington, Indiana.
AD  - Division of Pulmonary, Allergy, and Critical Care Medicine, Department of 
      Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
AD  - Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at 
      Birmingham, Birmingham, Alabama.
FAU - Paris, Hunter L
AU  - Paris HL
AD  - HH Morris Human Performance and Exercise Biochemistry Laboratory, Department of 
      Kinesiology, School of Public Health-Bloomington, Indiana University, 
      Bloomington, Indiana.
FAU - Beck, Christopher P
AU  - Beck CP
AD  - HH Morris Human Performance and Exercise Biochemistry Laboratory, Department of 
      Kinesiology, School of Public Health-Bloomington, Indiana University, 
      Bloomington, Indiana.
FAU - Chapman, Robert F
AU  - Chapman RF
AD  - HH Morris Human Performance and Exercise Biochemistry Laboratory, Department of 
      Kinesiology, School of Public Health-Bloomington, Indiana University, 
      Bloomington, Indiana.
FAU - Mickleborough, Timothy D
AU  - Mickleborough TD
AD  - HH Morris Human Performance and Exercise Biochemistry Laboratory, Department of 
      Kinesiology, School of Public Health-Bloomington, Indiana University, 
      Bloomington, Indiana.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Strength Cond Res
JT  - Journal of strength and conditioning research
JID - 9415084
RN  - 0 (Blood Glucose)
RN  - 0 (Dietary Carbohydrates)
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Athletic Performance/*physiology
MH  - Bicycling/*physiology
MH  - Blood Glucose/metabolism
MH  - Dietary Carbohydrates/*administration & dosage
MH  - Drug Administration Schedule
MH  - Exercise Test
MH  - Humans
MH  - Male
MH  - Muscle Strength
MH  - Muscle, Skeletal
MH  - Random Allocation
MH  - Time Factors
MH  - Young Adult
EDAT- 2017/09/14 06:00
MHDA- 2018/10/27 06:00
CRDT- 2017/09/14 06:00
PHST- 2017/09/14 06:00 [pubmed]
PHST- 2018/10/27 06:00 [medline]
PHST- 2017/09/14 06:00 [entrez]
AID - 10.1519/JSC.0000000000002226 [doi]
PST - ppublish
SO  - J Strength Cond Res. 2018 Aug;32(8):2243-2249. doi: 10.1519/JSC.0000000000002226.