Endurance.Net Ridecamp Archives

  Body heat is waste heat.  How much waste heat a given activity generates depends 
primarily on two factors - how much energy is expended and what fuel is used. Waste 
heat is always a byproduct of any activity whether it be walking, running, lifting 
weights, eating food or even sleeping.  The more energy an activity requires, the 
more waste heat it produces.  When digesting food, grains are more easily digested 
that grain hays and so their digestion produces less waste heat.  Similarly, grain 
hays are easier to digest than grass hays so digesting the latter produce more waste 
heat.  That is why vets recommend feeding grass hay to help maintain body 
temperature.  Alfalfa cut at an early stage of development has less lignin than most 
grain or grass hays and so is more easily digested while alfalfa cut at a later stage 
of development will have more lignin (be more stemy) and thus be harder to digest. 
But that is only the first factor.
  The body metabolizes carbohydrates pretty efficiently, thus not a great deal of 
waste heat is generated (much of the nutritive value in grass hays comes from 
carbohydrates).  It metabolizes fat somewhat less efficiently and therefore slightly 
more body heat is generated.  The body metabolizes proteins very inefficiently thus 
metabolizing protein produces a sizable amount of waste heat.

  In an article in the June, 2000, issue of Endurance News, "Beating the Metabolic 
Pull, Part 1 - Hydration", Susan Garlinghouse, MS, states:

While excess protein does contribute to energy production, the pathway is a 
relatively inefficient one, as protein metabolism produces 3-6 times more waste heat 
than does the utilization of an equivalent amount of carbohydrates or fat. In cold 
climates, this heat production from excess protein can be used to help maintain body 
temperature, especially during the off-season.


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

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!!

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