Circadian rhythm, activity level, training habits and sports performance : the molecular and subjective components

• Main Author: Stephenson, Kim Jenna
• Other Authors: Rae, Dale
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2014
• Subjects: Medicine
• Online Access: http://hdl.handle.net/11427/5925

Includes abstract. === Includes bibliographical references. === Circadian rhythmicity, which is driven by a circadian clock, is a property of a biological process that displays an oscillation of approximately 24-hours even in the absence of external time cues. Individual differences in the preferred times of waking, activity and rest (sleep) are known as chronotype or diurnal preference; which arise due to differences in circadian rhythmicity due to the fact that rhythms are not exactly 24-hours. Various polymorphisms of certain genes involved in circadian rhythm generation have been associated with extreme chronotype. Of interest to this study is the PER3 gene as it has a variable number tandem repeat (VNTR) polymorphism in the coding region, which is repeated either four of five times, encoding proteins of different lengths.