title: Co-ingestion of caffeine and carbohydrate after meal does not improve performance at high-intensity intermittent sprints with short recovery times.
abstract: OBJECTIVE
  To determine the effects of co-ingesting caffeine (CAF) and carbohydrate (CHO) on high-intensity intermittent sprints (HIS) performance and physiological responses.
  
  
  METHODS
  Twelve active males underwent 4 interventions at least 7 days apart in a randomized, double-blind, placebo-controlled, balanced trial. A meal contained 65 % CHO was provided 2 h before the HIS test. Participants ingested the placebo (PLA) or CAF (6 mg kg(-1) BW) 1 h before taking an HIS test, and ingested a PLA or CHO solution (0.8 g kg(-1) BW) before undergoing the testing protocol. The HIS protocol comprised ten sets of 5 × 4-s sprints on a cycle ergometer with a 2-min recovery between each set.
  
  
  RESULTS
  There was no significant difference between peak power output and mean power output between trials (p > 0.05). Compared with PLA, CAF + CHO resulted in a 5.2 % reduction in total work, corresponding to a 24.7-25.7 % increase in fatigue at the end stage of the HIS. The administration of CAF + CHO supplementation also resulted in an 11.1 % increase in blood lactate, and elevated blood glucose concentrations throughout HIS testing compared with PLA (p < 0.05). Cortisol concentrations also increased with CAF + CHO intake compared with PLA; however, there was no significant effect of CAF + CHO supplementation on testosterone concentrations.
  
  
  CONCLUSIONS
  Co-ingestion of CAF and CHO did not improve high-intensity sprint cycling performance or reduce fatigue in active males. Moreover, combined CAF and CHO supplementation might facilitate catabolism during prolonged high-intensity intermittent exercise.
authors.affiliation: Physical Education Section of General Education, National Sun Yat-sen University, Kaohsiung, Taiwan, karenlee1129@gmail.com.
authors.forename: Chia-Lun
authors.initials: CL
authors.lastname: Lee
authors.forename: Ching-Feng
authors.initials: CF
authors.lastname: Cheng
authors.forename: Chia-Jung
authors.initials: CJ
authors.lastname: Lee
authors.forename: Yu-Hsuan
authors.initials: YH
authors.lastname: Kuo
authors.forename: Wen-Dien
authors.initials: WD
authors.lastname: Chang
mesh_terms: D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D002110:Caffeine / Q000008:administration & dosage*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage*; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004311:Double-Blind Method; D005080:Exercise Test; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D019344:Lactic Acid / Q000097:blood; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D018763:Muscle Fatigue; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D010807:Physical Endurance / Q000187:drug effects*; D020127:Recovery of Function; D013624:Taiwan; D013739:Testosterone / Q000097:blood; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D000697:Central Nervous System Stimulants; D004040:Dietary Carbohydrates; D019344:Lactic Acid; D002110:Caffeine; D013739:Testosterone; D006854:Hydrocortisone
references.citation: Appl Physiol Nutr Metab. 2008 Jun;33(3):441-9
references.pmid: 18461096
references.citation: Sports Med. 2009;39(10):813-32
references.pmid: 19757860
references.citation: J Appl Physiol (1985). 2005 Sep;99(3):844-50
references.pmid: 15831802
references.citation: Eur J Appl Physiol. 2011 Aug;111(8):1669-77
references.pmid: 21207054
references.citation: Appl Physiol Nutr Metab. 2008 Dec;33(6):1319-34
references.pmid: 19088794
references.citation: Med Sci Sports Exerc. 2008 Dec;40(12):2096-104
references.pmid: 18981939
references.citation: Int J Sport Nutr Exerc Metab. 2011 Feb;21(1):71-84
references.pmid: 21411838
references.citation: Am J Physiol. 1993 Sep;265(3 Pt 1):E380-91
references.pmid: 8214047
references.citation: Scand J Med Sci Sports. 2005 Apr;15(2):69-78
references.pmid: 15773860
references.citation: J Strength Cond Res. 2008 May;22(3):978-86
references.pmid: 18438212
references.citation: Eur J Appl Physiol. 2012 Jun;112(6):2107-16
references.pmid: 21960086
references.citation: J Appl Physiol (1985). 2011 Nov;111(5):1372-9
references.pmid: 21836046
references.citation: Eur J Appl Physiol Occup Physiol. 1992;65(2):188-91
references.pmid: 1396643
references.citation: J Sports Sci. 2010 Jun;28(8):833-42
references.pmid: 20521199
references.citation: Med Sci Sports. 1973 Summer;5(2):90-3
references.pmid: 4721012
references.citation: Int J Sport Nutr Exerc Metab. 2002 Dec;12(4):438-52
references.pmid: 12500987
references.citation: J Sports Sci. 2012;30(10):975-83
references.pmid: 22616569
references.citation: Eur J Appl Physiol. 2003 Jan;88(4-5):453-8
references.pmid: 12527977
references.citation: Sports Med. 2005;35(12):1025-44
references.pmid: 16336007
references.citation: Int J Sport Nutr Exerc Metab. 2014 Feb;24(1):79-89
references.pmid: 23980237
references.citation: Int J Sport Nutr Exerc Metab. 2007 Feb;17(1):35-55
references.pmid: 17460332
references.citation: Nutr J. 2013 Jan 28;12:16
references.pmid: 23356905
references.citation: Sports Med. 2011 Aug 1;41(8):673-94
references.pmid: 21780851
references.citation: Am J Physiol Regul Integr Comp Physiol. 2003 Feb;284(2):R399-404
references.pmid: 12399249
references.citation: Int J Sports Med. 1994 Apr;15(3):122-5
references.pmid: 8005723
references.citation: Sports Med. 2011 Jul 1;41(7):559-85
references.pmid: 21688869
references.citation: J Strength Cond Res. 2011 May;25(5):1225-8
references.pmid: 21522070
references.citation: Int J Sports Med. 2011 Sep;32(9):659-65
references.pmid: 21913140
references.citation: Int J Sport Nutr Exerc Metab. 2006 Oct;16(5):528-44
references.pmid: 17240784
references.citation: J Appl Physiol (1985). 1993 Oct;75(4):1477-85
references.pmid: 8282593
references.citation: Med Sci Sports Exerc. 2008 Jan;40(1):96-103
references.pmid: 18091017
references.citation: Med Sci Sports Exerc. 1999 Sep;31(9):1280-6
references.pmid: 10487369
references.citation: J Sports Sci. 2010 Apr;28(6):593-601
references.pmid: 20391081
references.citation: J Clin Endocrinol Metab. 2000 Jun;85(6):2170-5
references.pmid: 10852448
references.citation: Med Sci Sports Exerc. 2001 May;33(5):822-5
references.pmid: 11323555
references.citation: Exp Physiol. 2001 Jan;86(1):137-44
references.pmid: 11429627
references.citation: Sports Med. 2000 Jun;29(6):407-24
references.pmid: 10870867
references.citation: Med Sci Sports Exerc. 2009 Sep;41(9):1744-51
references.pmid: 19657295
references.citation: Med Sci Sports Exerc. 2007 Sep;39(9):1554-60
references.pmid: 17805088
references.citation: Appl Physiol Nutr Metab. 2013 Jun;38(6):633-7
references.pmid: 23724880
references.citation: Appl Physiol Nutr Metab. 2008 Dec;33(6):1079-85
references.pmid: 19088765
references.citation: J Sports Sci. 2004 Jul;22(7):637-43
references.pmid: 15370494
references.citation: J Int Soc Sports Nutr. 2013 Jan 24;10(1):4
references.pmid: 23347391
references.citation: Crit Rev Food Sci Nutr. 2005;45(7-8):535-62
references.pmid: 16371327
references.citation: Med Sci Sports Exerc. 2006 Mar;38(3):578-85
references.pmid: 16540848
references.citation: Acta Physiol (Oxf). 2011 Feb;201(2):227-38
references.pmid: 21241457
references.citation: Eur J Appl Physiol. 2012 Mar;112(3):1133-41
references.pmid: 21750974
references.citation: Appl Physiol Nutr Metab. 2009 Aug;34(4):681-8
references.pmid: 19767804
references.citation: Int J Sports Med. 1999 Jul;20(5):309-14
references.pmid: 10452228
references.citation: Int J Sports Med. 1999 Jan;20(1):48-52
references.pmid: 10090462
references.citation: J Physiol. 2000 Dec 15;529 Pt 3:837-47
references.pmid: 11118510
references.citation: J Appl Physiol (1985). 1991 Dec;71(6):2292-8
references.pmid: 1778925
references.citation: Int J Sport Nutr Exerc Metab. 2010 Jun;20(3):191-7
references.pmid: 20601736
references.citation: J Sci Med Sport. 2004 Sep;7(3):278-91
references.pmid: 15518293
references.citation: J Appl Physiol (1985). 1996 Oct;81(4):1658-63
references.pmid: 8904583
references.citation: Med Sci Sports Exerc. 2007 Nov;39(11):1969-76
references.pmid: 17986904
references.citation: J Appl Physiol (1985). 2008 Jul;105(1):7-13
references.pmid: 18467543
references.citation: Appl Physiol Nutr Metab. 2012 Apr;37(2):276-83
references.pmid: 22436075
references.citation: Med Sci Sports. 1978 Fall;10(3):155-8
references.pmid: 723503
references.citation: J Sports Sci. 1995 Aug;13(4):283-90
references.pmid: 7474041
references.citation: Percept Mot Skills. 2007 Jun;104(3 Pt 2):1079-87
references.pmid: 17879641
references.citation: Int J Sport Nutr Exerc Metab. 2000 Dec;10(4):476-85
references.pmid: 11099374
references.citation: J Appl Physiol (1985). 2000 Sep;89(3):1079-85
references.pmid: 10956354