Physical work capacity in blood donors.

Abstract

The iron state (haemoglobin, serum iron, total iron-binding capacity, and stainable bone-marrow iron) and physical performance (work load at heart rate 170 beats/min) were investigated in 18 male blood donors who had given blood more than 50 times at a rate of about five times yearly. Half the group were then given iron by mouth, and the rest placebo tablets for 15 weeks, after which the tests were repeated. In spite of an improved iron state in the Iron Group (considerable amounts of iron were deposited as stainable iron in the bone-marrow), the physical work capacity remained unchanged. In the Placebo Group both the iron state and the work performance were unaltered.