Elevation of hemoglobin and work tolerance in iron-deficient subjects.

Abstract

Selected parameters related to work tolerance were measured in 31 adult [human] subjects with Hb concentration from 2.5-14.0 g/100 ml. Work tolerance was closely related to Hb concentration (r = 0.74) regardless of the adequacy of storage Fe level. One male and 6 females with a mean Hb of 3.5 g/100 ml (27-55 yr old) were studied before and 24 h after transfusing 570 ml of whole blood. The mean maximal work load tolerated increased 83% within 24 h after transfusion in these 7 subjects. Post-exercise venous blood lactate was markedly lower after transfusion. Work tolerance of these subjects within 24 h after transfusion was the same as in other subjects who had had the equivalent Hb level as the post-transfusion subjects presumably for at least several weeks. Apparently the decrement in work performance capacity in Fe-deficient and anemic subjects is, in large part, a reflection of the level of anemia rather than other non-Hb related biochemical changes that could accompany prolonged Fe deficiency anemia.