Energetics resting muscles

The body will do what it needs in order to acquire and store energy. Muscle tissue itself,however, is energetically expensive to maintain Even at rest,your skeletal muscles consume about 25 percent of your energy.Thus, it is not in your body s interest to have more muscle mass than it needs. For this reason, our muscles adapt. If we exercise a lot, our muscles become bigger and stronger. Conversely, muscles wither away without exercise—a fully immobilized muscle loses about one-third of its mass within weeks. From personal experience we know that muscles are responsive to use. But how is this accomplished Why is it that when you exercise your muscles get stronger and when you don t they get weaker The answer is that exer-... 

ShmerUng, M.D., Buzueva, IJ. and Filyushina, E.E. (1984). The electronic microscopic study of grayling skeletal muscles at rest and with muscular loads (In Russian). In Studies of fish locomotion energetics , pp. 61-68. Nauka, Novosibirsk, Siberian Branch. 

Little calorimetric research has been done on smooth muscle. Recently, however, Lonnbro and Hellstrand (1991) showed that chemically skinned muscle from guinea pig taenia coli produced threefold more heat on activation (pCa 4.8) than at rest (pCa 9) (pCa being -log Ca2+). With stepwise increments in [Ca2+] from pCa 9 to 4.8, the energetic cost of force maintenance tended to rise at higher [Ca2+]. Even after Ca2+ activation, force still increased beyond the point at which heat dissipation reached its maximum. 

Dawson et al (1975, 1977) extended the P NMR technique to investigate the energetically important phosphate compounds of living muscle in different states, namely, rest, contraction, and recovery. They used the same 129 MHz spectrometer used by the Oxford group in their original muscle studies. They emphasized the desirability of measuring function as well as the spectrum in different physiological states. The major problem that had... 

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