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Energy-Rich Phosphagens

1971; Springer Nature; Linguagem: Inglês

10.1007/978-1-4613-4609-8_29

2214-8019

R. E. Davies,

Muscle metabolism and nutrition

It has, of course, been known for a long time that when you work you get tired, and that if you work hard you breathe hard, and when you stop working you keep breathing hard for a while as you recover. It is also clear that walking up a mountain is more tiring than walking down a mountain, although the reason for this is not so obvious as it might appear. Chemical changes in the muscles during exercise have been studied for a remarkably long time. For instance, an increase of lactic acid in the muscles of deers which have been run to exhaustion was discovered by Berzelius in 1841, and as far back as 1871, Weiss showed that the glycogen content of muscles decreased with work. Even the fact that creatine was formed by working muscles was observed by Monari in 1889 and the liberation of inorganic phosphate from an organic compound during activity was recorded by Salkowski in 1890. The work of Fletcher & Hopkins (1907) supported the lactic acid theory of muscle contraction which was based on the belief that the breakdown of glucose to lactic acid was the immediate energy source.