Effect of exercise on blood volume.

Abstract

The influence of regularly performed exercise on total blood volume (TBV) in 14 previously sedentary males aged 26-64 yr. was investigated. TBV, as estimated by means of radioiodinated (131I) human serum albumin, increased 338 ml (P < 0.05) following 47 running sessions over a 16-week period. This 6% increase in TBV was due to an elevation in plasma volume; red cell volume did not change singificantly. TBV did not change significantly in a sedentary control group. Maximal O2 intake, used as an index of improvement in exercise capacity, increased 560 ml (18%, P < 0.05) Exercise resulting in a significant increase in maximal oxygen intake may be associated with an increase in TBV.