Observations on Experimental Muscular Soreness

Abstract

SummaryIn order to find out whether the muscular soreness which appears 12—24 hours after a bout of hard unaccustomed exercise, is due to the greatly increased metabolism in the working muscles, or whether it is caused by injuries evoked by the mechanical tensions in the muscles, a series of experiments were performed with positive and negative work. The tensions developed during these two kinds of work were the same in both cases, but the metabolism is known to be several times greater with postive work than with negative work.It was found that muscular soreness with palpable muscular changes was always present 1 to 2 days after negative work, but hardly ever after positive work of the same intensity.It is concluded that muscular soreness is called forth by mechanical stress most probably to the intramuscular connective tissue, and not by metabolic waste products. The reason for its appearance in negative work and absence in positive work is discussed, and a tentative proposal for its causes is given.