title: Effect of long-term physical training on total red cell volume.
abstract: Six months of military training elicited a significant 4% mean increase in total red cell volume (TRC) measured by the 51Cr-labelled red cell method. This increase was associated with a mean 16% increase in predicted maximal oxygen uptake (VO2max). The increases in TRCV and predicted VO2max were inversely related to their initial levels. A statistically highly significant correlation between TRCV and predicted VO2max was observed (r = 0.59). The trained group had larger initial TRCVs than the sedentary group and the subjects who became well conditioned had a significant increase in TRCV, which contrasted with the unchanged TRCV in the subjects who did not become well conditioned. The greatest increase in TRCV (11%) was found in corporals, who had the hardest training. A statistically significant correlation between the changes in TRCV and estimated plasma volume was observed (r = 0.62), P less than 0.001). Owing the 1.8% increase in body weight the TRCV and predicted VO2max in terms relative to the body weight did not demonstrate the changes as clearly as did the absolute values. The factors affecting the TRCV increase are discussed.
mesh_terms: D000328:Adult; D004909:Erythrocyte Indices; D004911:Erythrocyte Volume; D004920:Erythropoiesis; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010806:Physical Education and Training; D010953:Plasma Volume; D013997:Time Factors
chemical_list: D006454:Hemoglobins