Hematologic Changes in Man Resulting from a Regimen of Isometric Exercise

Abstract Twelve human subjects were assigned to two groups of equal numbers. One group trained isometrically; the other served as a control. Resting blood samples were taken 1, 3, 5, 7, and 8½ weeks after initiation of training, and 2 and 3 weeks after cessation of training. Blood was examined for coagulation time, hemoglobin concentration, and for erythrocyte, leucocyte, and platelet counts. Packed cell volumes were determined before and after training. Scores indicative of muscular strength were recorded throughout training. Isometric training may have produced a chronic decrease in coagulation time; it had no effect on hemoglobin concentration or on erythrocyte, leucocyte, and platelet counts. Increases in scores indicative of muscular strength were statistically significant (1 percent level of probability).