title: Prolonged sleep deprivation and continuous exercise: effects on melatonin, tympanic temperature, and cognitive function.
abstract: The purpose of this study was to examine tympanic temperature, melatonin, and cognitive function during a 36-hour endurance event. Nine male and three female participants took part in a 36-hour sustained endurance event without sleep (N = 12, mean age = 31.8 ± 5.0 yrs). Participants were stopped for data collection at checkpoints throughout the 36-hour event. Tympanic temperature was assessed, a psychomotor vigilance test (PVT) was administered, and saliva samples were collected. Salivary melatonin was determined via immunoassay. During the 36 hours of competition, melatonin levels were negatively correlated with the day of the race (rs = -0.277, P = 0.039) and positively associated with nighttime (rs = 0.316, P = 0.021). Significant main effects of tympanic temperature (P < 0.001), day of the competition (P = 0.018), and a tympanic temperature ∗ day of competition interaction (P < 0.001) were used to predict minor lapses in attention. No associations between melatonin levels and cognitive function were observed (P > 0.05). During the event tympanic temperature declined and was associated with an increase in lapses in attention. With sustained endurance events becoming more popular future research is warranted to evaluate the physiological impact of participation.
authors.affiliation: School of Kinesiology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
authors.forename: Greggory R
authors.initials: GR
authors.lastname: Davis
authors.affiliation: School of Kinesiology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
authors.forename: Corey E
authors.initials: CE
authors.lastname: Etheredge
authors.affiliation: School of Kinesiology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
authors.forename: Lena
authors.initials: L
authors.lastname: Marcus
authors.affiliation: School of Kinesiology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA.
authors.forename: David
authors.initials: D
authors.lastname: Bellar
mesh_terms: D000328:Adult; D001831:Body Temperature / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004432:Ear, Middle / Q000503:physiopathology*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D008550:Melatonin / Q000378:metabolism*; D012420:Running; D012892:Sleep Deprivation / Q000503:physiopathology*
chemical_list: D008550:Melatonin
references.citation: Int J Neurosci. 2001 Jul;109(1-2):127-37
references.pmid: 11699337
references.citation: Psychoneuroendocrinology. 1979 Jul;4(3):219-25
references.pmid: 515290
references.citation: Life Sci. 1990;47(22):1989-95
references.pmid: 2273939
references.citation: Wilderness Environ Med. 2005 Winter;16(4):177-84
references.pmid: 16366197
references.citation: Am J Physiol Regul Integr Comp Physiol. 2002 Dec;283(6):R1370-7
references.pmid: 12388468
references.citation: Psychon Bull Rev. 2009 Aug;16(4):742-51
references.pmid: 19648462
references.citation: Indian J Psychol Med. 2012 Apr;34(2):129-32
references.pmid: 23162187
references.citation: Aviat Space Environ Med. 2009 Aug;80(8):703-8
references.pmid: 19653572
references.citation: Eur J Appl Physiol Occup Physiol. 1994;69(3):216-20
references.pmid: 8001532
references.citation: Chronobiol Int. 2013 Aug;30(7):901-9
references.pmid: 23738906
references.citation: Clin Neurophysiol. 2006 Sep;117(9):1885-901
references.pmid: 16581292
references.citation: J Comp Physiol B. 2009 Aug;179(6):701-10
references.pmid: 19277681
references.citation: Paediatr Nurs. 2009 Jul;21(6):40-3
references.pmid: 19623803
references.citation: Chronobiol Int. 2012 Jun;29(5):537-48
references.pmid: 22621349
references.citation: Physiol Behav. 2006 Feb 28;87(2):396-408
references.pmid: 16403541
references.citation: J Sleep Res. 1996 Sep;5(3):150-4
references.pmid: 8956204
references.citation: Med Sci Sports Exerc. 1988 Aug;20(4):374-80
references.pmid: 3173045
references.citation: J Sports Sci. 2009 May;27(7):719-28
references.pmid: 19437188
references.citation: Sleep. 2011 May 01;34(5):581-91
references.pmid: 21532951
references.citation: Aviat Space Environ Med. 2009 Jul;80(7):629-36
references.pmid: 19601505
references.citation: J Appl Physiol (1985). 2006 Nov;101(5):1481-8
references.pmid: 16840581
references.citation: Sleep. 2012 Dec 01;35(12):1673-83
references.pmid: 23204610
references.citation: Sleep. 1999 May 1;22(3):328-34
references.pmid: 10341383
references.citation: Eur J Appl Physiol. 2013 Sep;113(9):2323-9
references.pmid: 23771573
references.citation: J Sleep Res. 2013 Feb;22(1):83-8
references.pmid: 22889464
references.citation: Mil Med. 2011 May;176(5):488-93
references.pmid: 21634291
references.citation: Sleep. 2007 Nov;30(11):1437-43
references.pmid: 18041478
references.citation: Sleep. 1988 Aug;11(4):362-9
references.pmid: 3206055
references.citation: Mil Med. 2013 May;178(5):479-86
references.pmid: 23756004
references.citation: Physiol Behav. 2006 Jan 30;87(1):166-76
references.pmid: 16309719
references.citation: Sleep. 1997 Apr;20(4):267-77
references.pmid: 9231952
references.citation: J Sleep Res. 2006 Mar;15(1):7-13
references.pmid: 16489997
references.citation: Chronobiol Int. 2010 Jul;27(5):898-910
references.pmid: 20636204