Isometric burn II

All--

Apropos of jmw's correct assertion about rigor mortis elsewhere, here's a
thought:
IF
1. ATP indeed powers the *release* of the myosin head from actin;
2. Which means a flaccid un-tensed muscle is actually burning ATP (part of
your BMR)
3. An isometric represents a near-maximum number of actin-myosin bridges,
ie, NO ATP hydrolysis as long as they are stuck together,
THEN
An isometric contraction actually consumes a *minimal* amount of energy--and
that the imminent fatigue is *not* lactic acid induced, but purely
neural--as I think jmw was suggesting, and as his cite was suggesting.

Said minimal amount of consumed energy is proly not as low as in flaccid
muscle (as this argument might tend to imply), but it might be
*disproportionately close*!

Which, from an evolutionary/survival point of view, is absolutely brilliant:

Think of animals surviving via isometric-type exertions: primates swinging
(lock-jointed) in trees, cats holding themselves in trees by claws alone,
other examples of "motionless force", such as three-toed sloths feeding
endlessly while clinging w/ their full bodyweight, etc, all accomplished
with a minimal consumption of ATP, as there is no ATP needed for a "rigor
mortised" type contraction--ie, contractions w/o motion!

For which there is excellent experimental evidence, right within us, that I
was going to get to earlier in the other isometric thread:
Even after an intense isometric workout, one's breathing rate is
*surprisingly low*, despite very large-muscle contractions, ergo little VO2,
ERGO very little calorie burn, as compared to vigorous lifting or running.
Very little.

IOW, it is the nature of muscle to isometrically contract w/ very little
chemical/metabolic energy consumed! *Adjusting* said contraction is where
the energy consumption comes in.

Man, ahm tickled, just fukn tickled! I think....
--
Mr. P.V.'d (formerly Droll Troll), Yonkers, NY
Stop Corruption in Congress & Send the Ultimate Message:
Absolutely Vote, but NOT for a Democrat or a Republican.
Ending Corruption in Congress is the Single Best Way
to Materially Improve Your Family's Life.
entropic3.14decay at optonline2.718 dot net; remove pi and e to reply--ie,
all d'numbuhs