Review Athletes ' anaemia A review of possible causes and guidelines on investigationt

Athletes ' anaemia (sports anaemia) is well recognized and there have been many suggestions for its aetiology some leading to unnecessary anxiety as well as needless investiga-tion and treatment. This article reviews evidence on the causes of sports anaemia and suggests how to identify the few cases that require investigation and treatment. It seems paradoxical that when most physiological para-meters show improved function that the haemoglobin level should fall with training but most studies (including run-ners, rowers, cyclists, swimmers and walkers) show that endurance trained athletes have a haemoglobin level about 0.5 g 100 ml lower than untrained controls. Forty-four per cent of soldiers in basic combat training were found to have a haematocrit below 41 per cent compared with eleven per cent of soldiers not in training'