Biochemical adaptation as a response to exercise. 1. Effect of swimming on the levels of lactic dehydrogenase, malic dehydrogenase and phosphorylase in muscles of 8-, 11- and 15-week-old rats

Although adaptation to physical training has received extensive study from the aspects of performance and physiological effects (Astrand, 1956), there is little information on this effect at the cellular level.It is significant that the compre- hensive review of enzyme adaptation by Knox, Auerbach & Lin (1956) makes no reference what- ever to enzymic changes accompanying athletic training.Most of the published work in this field stems from the Leningrad Physical Culture Research Institute (Yakovlev, 1950; Yampolskaya & Yak- ovlev, 1951; Yampolskaya, 1952).These workers claim that muscle analyses after training have