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BioMed Research International
Volume 2014, Article ID 781863, 6 pages
Research Article

Prolonged Sleep Deprivation and Continuous Exercise: Effects on Melatonin, Tympanic Temperature, and Cognitive Function

School of Kinesiology, University of Louisiana at Lafayette, Lafayette, LA 70504, USA

Received 28 February 2014; Revised 10 June 2014; Accepted 15 June 2014; Published 6 July 2014

Academic Editor: Edward J. Ryan

Copyright © 2014 Greggory R. Davis et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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 ( , mean age = 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 ( , ) and positively associated with nighttime ( , ). Significant main effects of tympanic temperature ( ), day of the competition ( ), and a tympanic temperature day of competition interaction ( ) were used to predict minor lapses in attention. No associations between melatonin levels and cognitive function were observed ( ). 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.