Home Current News News Archive Shop/Advertise Ridecamp Classified Events Learn/AERC
Endurance.Net Home Ridecamp Archives
ridecamp@endurance.net
[Archives Index]   [Date Index]   [Thread Index]   [Author Index]   [Subject Index]

[RC] Circadian Rhythms - Ridecamp Guest

Please Reply to: ti tivers@xxxxxxx or ridecamp@xxxxxxxxxxxxx
==========================================

Authors J Waterhouse, B Drust, D Weinert, B Edwards, W Gregson, G Atkinson, SY 
Kao, S Aizawa, T Reilly
Title   The circadian rhythm of core temperature: Origin and some implications 
for exercise performance
Full source     Chronobiology International, 2005, Vol 22, Iss 2, pp 207-225

This review first examines reliable and convenient ways of measuring core 
temperature for studying the circadian rhythm, concluding that measurements of 
rectal and gut temperature fulfil these requirements, but that insulated axilla 
temperature does not. The origin of the circadian rhythm of core temperature is 
mainly due to circadian changes in the rate of loss of heat through the 
extremities, mediated by vasodilatation of the cutaneous vasculature. 
Difficulties arise when the rhythm of core temperature is used as a marker of 
the body clock, since it is also affected by the sleep-wake cycle. This masking 
effect can be overcome directly by constant routines and indirectly by 
''purification'' methods, several of which are described. Evidence supports the 
value of purification methods to act as a substitute when constant routines 
cannot be performed. Since many of the mechanisms that rise to the circadian 
rhythm of core temperature are the same as those that occur during 
thermoregulation in exercise, there is an interaction between the two. This 
interaction is manifest in the initial response to spontaneous activity and to 
mild exercise, body temperature rising more quickly and thermo regulatory 
reflexes being recruited less quickly around the trough and rising phase of the 
resting temperature rhythm, in comparison with the peak and falling phase. 
There are also implications for athletes, who need to exercise maximally and 
with minimal risk of muscle injury or heat exhaustion in a variety of ambient 
temperatures and at different times of the day. Understanding the circadian 
rhythm of core temperature may reduce potential hazards due to the time of day 
when exercise is performed.


=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Ridecamp is a service of Endurance Net, http://www.endurance.net.
Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp
Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp

Ride Long and Ride Safe!!

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-