PMID- 23977198
OWN - NLM
STAT- MEDLINE
DCOM- 20140408
LR  - 20211021
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 8
IP  - 8
DP  - 2013
TI  - Caffeine increases anaerobic work and restores cycling performance following a 
      protocol designed to lower endogenous carbohydrate availability.
PG  - e72025
LID - 10.1371/journal.pone.0072025 [doi]
LID - e72025
AB  - The purpose this study was to examine the effects of caffeine ingestion on 
      performance and energy expenditure (anaerobic and aerobic contribution) during a 
      4-km cycling time trial (TT) performed after a carbohydrate (CHO) 
      availability-lowering exercise protocol. After preliminary and familiarization 
      trials, seven amateur cyclists performed three 4-km cycling TT in a double-blind, 
      randomized and crossover design. The trials were performed either after no 
      previous exercise (CON), or after a CHO availability-lowering exercise protocol 
      (DEP) performed in the previous evening, followed by either placebo (DEP-PLA) or 
      5 mg.kg(-1) of caffeine intake (DEP-CAF) 1 hour before the trial. Performance was 
      reduced (-2.1%) in DEP-PLA vs CON (421.0+/-12.3 vs 412.4+/-9.7 s). However, 
      performance was restored in DEP-CAF (404.6+/-17.1 s) compared with DEP-PLA, while 
      no differences were found between DEP-CAF and CON. The anaerobic contribution was 
      increased in DEP-CAF compared with both DEP-PLA and CON (67.4+/-14.91, 47. 3+/-14.6 
      and 55.3+/-14.0 W, respectively), and this was more pronounced in the first 3 km of 
      the trial. Similarly, total anaerobic work was higher in DEP-CAF than in the 
      other conditions. The integrated electromyographic activity, plasma lactate 
      concentration, oxygen uptake, aerobic contribution and total aerobic work were 
      not different between the conditions. The reduction in performance associated 
      with low CHO availability is reversed with caffeine ingestion due to a higher 
      anaerobic contribution, suggesting that caffeine could access an anaerobic 
      "reserve" that is not used under normal conditions.
FAU - Silva-Cavalcante, Marcos David
AU  - Silva-Cavalcante MD
AD  - Sports Science Research Group, Faculty of Nutrition, Federal University of 
      Alagoas, Maceio, Alagoas, Brazil ; Endurance Performance Research Group, School 
      of Physical Education and Sport, University of Sao Paulo, Sao Paulo, Sao Paulo, 
      Brazil.
FAU - Correia-Oliveira, Carlos Rafaell
AU  - Correia-Oliveira CR
FAU - Santos, Ralmony Alcantara
AU  - Santos RA
FAU - Lopes-Silva, Joao Paulo
AU  - Lopes-Silva JP
FAU - Lima, Hessel Marani
AU  - Lima HM
FAU - Bertuzzi, Romulo
AU  - Bertuzzi R
FAU - Duarte, Marcos
AU  - Duarte M
FAU - Bishop, David John
AU  - Bishop DJ
FAU - Lima-Silva, Adriano Eduardo
AU  - Lima-Silva AE
LA  - eng
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, Non-U.S. Gov't
DEP - 20130819
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 33X04XA5AT (Lactic Acid)
RN  - 3G6A5W338E (Caffeine)
SB  - IM
MH  - Adult
MH  - Anaerobic Threshold/*drug effects
MH  - Bicycling
MH  - Caffeine/*pharmacology
MH  - Carbohydrate Metabolism
MH  - Cross-Over Studies
MH  - Diet, Carbohydrate-Restricted
MH  - Double-Blind Method
MH  - Heart Rate
MH  - Humans
MH  - Lactic Acid/blood
MH  - Oxygen Consumption/drug effects
PMC - PMC3747083
COIS- Competing Interests: The authors have declared that no competing interests exist.
EDAT- 2013/08/27 06:00
MHDA- 2014/04/09 06:00
PMCR- 2013/08/19
CRDT- 2013/08/27 06:00
PHST- 2013/03/22 00:00 [received]
PHST- 2013/07/04 00:00 [accepted]
PHST- 2013/08/27 06:00 [entrez]
PHST- 2013/08/27 06:00 [pubmed]
PHST- 2014/04/09 06:00 [medline]
PHST- 2013/08/19 00:00 [pmc-release]
AID - PONE-D-13-12390 [pii]
AID - 10.1371/journal.pone.0072025 [doi]
PST - epublish
SO  - PLoS One. 2013 Aug 19;8(8):e72025. doi: 10.1371/journal.pone.0072025. eCollection 
      2013.