Effects of caffeine ingestion on endurance performance in mentally fatigued individuals.
OBJECTIVE
To examine the effects of caffeine ingestion on physiological and perceptual responses in mentally fatigued individuals.


METHODS
Eight male physically active subjects completed four cycling constant-workload tests in four experimental conditions at 80 % of maximal power output: control (C), mental fatigue (MF), mental fatigue plus caffeine ingestion (5 mg/kg) (MF-CAF), and mental fatigue plus placebo (MF-PLA). The mental fatigue was induced by a continuous performance task A-X version (AX-CPT). Before and after the AX-CPT, the profile of mood state (POMS) and blood samples for lactate measurement were collected. Oxygen consumption ([Formula: see text]), rating of perceived exertion (RPE), and electromyography (EMG) activity were measured during the cycling test.


RESULTS
The time to exhaustion in C, MF, MF-PLA, and MF-CAF were 251 ± 30, 222 ± 23, 248 ± 28, and 285 ± 42 s, respectively. Delta values (corrected by C condition) were higher in MF-CAF than MF (P = 0.031). MF-CAF reported higher Vigor scores when compared with C (P = 0.046) and MF (P = 0.020). RPE at the first minute was significantly higher in MF-PLA than in C (P = 0.050); at the second minute, RPE was higher in MF-PLA than in C (P = 0.049) and MF-CAF (P = 0.048). EMG activity was not different between the conditions.


CONCLUSIONS
Caffeine ingestion increased approximately 14 % endurance performance after the induction of mental fatigue. This effect was accompanied by a tendency to improvement in mood state (i.e., vigor). Therefore, caffeine ingestion can promote a beneficial effect on endurance performance in mentally fatigued individuals.
Endurance Performance Research Group, Departamento de Esporte, School of Physical Education and Sport (GEDAE-USP), University of São Paulo, Av. Professor Melo de Moraes, 65, Cidade Universitária, São Paulo, SP, 05508-030, Brazil.
Rafael
R
Azevedo
Endurance Performance Research Group, Departamento de Esporte, School of Physical Education and Sport (GEDAE-USP), University of São Paulo, Av. Professor Melo de Moraes, 65, Cidade Universitária, São Paulo, SP, 05508-030, Brazil.|Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Recife, Brazil.
Marcos David
MD
Silva-Cavalcante
School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.|Rheumatology Department, School of Medicine, University of Sao Paulo, São Paulo, Brazil.
Bruno
B
Gualano
Sports Science Research Group, Academic Center of Vitoria, Federal University of Pernambuco, Recife, Brazil.
Adriano E
AE
Lima-Silva
Endurance Performance Research Group, Departamento de Esporte, School of Physical Education and Sport (GEDAE-USP), University of São Paulo, Av. Professor Melo de Moraes, 65, Cidade Universitária, São Paulo, SP, 05508-030, Brazil. bertuzzi@usp.br.
Romulo
R
Bertuzzi
D000284:Administration, Oral; D000339:Affect / Q000187:drug effects*; D002110:Caffeine / Q000008:administration & dosage*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D005222:Mental Fatigue / Q000503:physiopathology* / Q000517:prevention & control; D010807:Physical Endurance / Q000187:drug effects*; D005082:Physical Exertion / Q000187:drug effects*; D011597:Psychomotor Performance / Q000187:drug effects*; D016896:Treatment Outcome; D055815:Young Adult
D000697:Central Nervous System Stimulants; D002110:Caffeine
Caffeine ingestion; Endurance capacity; Mental fatigue; Mood state
Med Sci Sports Exerc. 2007 Aug;39(8):1374-9
17762371
Psychopharmacology (Berl). 1993;112(2-3):359-65
7871042
Int J Sports Med. 2013 Dec;34(12):1029-36
23771830
Eur J Appl Physiol. 2010 May;109(2):287-95
20082092
J Appl Physiol (1985). 2001 Oct;91(4):1535-44
11568134
Respir Physiol. 1999 Dec 1;118(2-3):103-15
10647856
Braz J Med Biol Res. 1998 Apr;31(4):581-5
9698813
Nutrition. 2010 Oct;26(10):932-8
20888549
J Physiol. 2001 Jun 15;533(Pt 3):891-902
11410644
J Psychopharmacol. 2005 Nov;19(6):620-6
16272184
Med Sci Sports Exerc. 1994 Sep;26(9):1071-7
7808238
Front Hum Neurosci. 2014 Sep 26;8:755
25309404
Brain Cogn. 2003 Oct;53(1):82-94
14572506
Brain Res. 2014 Jan 13;1542:49-55
24505624
J Sports Sci. 2006 Apr;24(4):433-9
16492607
Med Sci Sports Exerc. 1996 Aug;28(8):1049-55
8871916
Med Sci Sports Exerc. 1982;14(5):377-81
7154893
Med Sci Sports Exerc. 2015 Dec;47(12):2660-8
26083771
Eur J Appl Physiol Occup Physiol. 1998 Apr;77(5):427-33
9562293
Physiol Behav. 2012 May 15;106(2):211-7
22349482
Sports Med. 2000 Jul;30(1):1-15
10907753
Brain Res Rev. 2008 Nov;59(1):125-39
18652844
Int J Sports Med. 2008 Jun;29(6):524-8
18027309
PLoS One. 2013 Sep 18;8(9):e75399
24058684
PLoS One. 2013 Aug 19;8(8):e72025
23977198
Muscle Nerve. 2011 Jun;43(6):839-44
21488053
J Electromyogr Kinesiol. 2000 Oct;10(5):361-74
11018445
J Appl Physiol (1985). 1999 May;86(5):1527-33
10233114
Front Hum Neurosci. 2015 Feb 25;9:67
25762914
Med Sci Sports Exerc. 2010 Jul;42(7):1375-87
20019636
Am J Physiol Regul Integr Comp Physiol. 2003 Feb;284(2):R399-404
12399249
Med Sci Sports Exerc. 2009 Jan;41(1):3-13
19092709
J Appl Physiol (1985). 2009 Mar;106(3):857-64
19131473
Sports Med. 2014 Nov;44 Suppl 2:S175-84
25355191
Rev Neurosci. 2014;25(4):469-79
24926625
PLoS One. 2014 Jun 06;9(6):e99238
24905918
Int J Sport Nutr. 1998 Jun;8(2):95-104
9637189
Med Sci Sports Exerc. 2015 Mar;47(3):468-75
24977700
Int J Sport Nutr Exerc Metab. 2008 Dec;18(6):639-52
19164833
Med Sci Sports Exerc. 2013 Nov;45(11):2175-83
23591294
Med Sci Sports Exerc. 2006 Aug;38(8):1484-91
16888463
Med Sci Sports Exerc. 1995 Sep;27(9):1292-301
8531628
Psychophysiology. 1994 Nov;31(6):525-34
7846213
Sports Med. 2004;34(13):871-89
15487903
Int J Sports Med. 2006 Jun;27(6):444-7
16767608