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Warm and Cold Bloodedness
> >For a long time I have accepted the premise that prolonged physical exertion
> >is possible only for warm-blooded animals, but I have never understood the
> >reason why this ought to be true. If the advantage lies in the muscles being
> >warm and better able to move, then I would think that warm bloodedness would
> >be most beneficial for short bursts of speed because the muscles would
> >be warm. This would be irrelevent for prolonged activity because the muscles
> >would warm themselves. There must be something beyond the temperature itself
> >that supports the assertion, but I don't have any idea what it is.
> >Bart Singer
> I'm not a physiologist, but from observations of reptiles I wouldn't say
> that "prolonged activity" IS gained from endothermic muscle. Anacondas and
> crocodiles wrestling with mammalian prey don't seem to "tire out" that much
> quicker, if at all, than lions or tigers.
> Endotherms do seem to have the advantage of quicker recovery rates after
> periods of exertion. I'm fairly certain someone has worked on this subject,
> but for the life of me, I can't remember who.
> Thomas R. HOLTZ
The stamina limitations of many modern reptiles are nothing to do with
temperature (reptile muscle frequently operates at higher temperatures than
mammalian); it is more to do with the problem of supplying the muscle with
oxygenated blood, so that anaerobic metabolism predominates fairly quickly
after an initial burst of activity (usually a matter of minutes depending on
the species etc.). Activity does not cease at this point, but the consequent
build up of lactic acid leads to a problem of detoxification eventually, and
requires a subsequent period of lowered activity.