Extreme Physical Exertion Research Articles

Treatment with recombinant human erythropoietin induces a moderate rise in hematocrit and thrombin antithrombin in healthy subjects

Recombinant human erythropoietin (EPO) therapy in uremic patients raises the hematocrit (Hct) and increases physical exercise capacity (1,2) and quality of life (1). In general, partial correction of anemia to subnormal levels in uremic patients has proven to be safe with few serious adverse effects apart from hypertension (3). Ever since the advent of EPO the prospect of abuse of the hormone by sportsmen has been subject to scrutiny. Both maximal oxygen uptake and endurance capacity are increased after EPO treatment in healthy subjects (4). Moreover, EPO treatment in healthy subjects has been found to induce an accentuated blood pressure reaction after submaximal exercise (5). Previous studies have shown that extreme physical exertion can predispose to an increased intravascular coagulation (6). Moreover there is a significantly increased risk of thrombosis in patients with myeloproliferative disorders, particularly in polycythemia vera (7). An enhanced risk of cardiovascular events may therefore arise should sportsmen abuse EPO as a blood doping agent. The aim of this study was to examine the effects of an EPO-induced increase in Hct on the coagulation system in healthy subjects.

The physiology of extreme physical exertion

Regular physical activity can make an important contribution to maintaining a healthy body. However, insufficient knowledge of the biological laws underlying the training process may easily lead to excessive strain and injuries. Extremely strenuous activities, such as marathons and triathlons, require proper training and preparation. Knowledge of the physical and mental demands made by such strenuous effort can not only enhance the pleasure in sport but also make a significant contribution to preventing problems.

Eosinophilic Fasciitis, Reactive Hepatitis, and Splenomegaly

Eosinophilic fasciitis (EF) is an acute, idiopathic inflammatory disorder often manifested by tender swelling of the extremities after extreme physical exertion. It is usually without visceral complications. I treated a 25-year-old man with EF who had reactive hepatitis and splenomegaly. To my knowledge, the former has never been reported and the latter only once.

Iron Deficiency Anemia in a Vegetarian Runner

To the Editor.— Sports anemia is a well-described but less well-known and understood complication of extreme physical exertion. Despite numerous studies,1,2the actual incidence of iron deficiency in well-trained athletes, including long-distance runners, is uncertain. These anemias are usually latent and may be manifested by a low-percent saturation of total iron-binding capacity,2low serum ferritin levels,2and low or absent bone marrow iron reserves.3 We present a case of severe iron deficiency anemia in a long-distance vegetarian runner. Report of a Case.— A previously healthy 28-year-old physician had followed a strict vegetarian diet for ten years. His estimated daily iron intake was 16.8 mg. During this same ten-year period, the patient engaged in vigorous physical exercise averaging 90 miles of running per week. He had noted painless gross hematuria following this exercise eight times during the previous ten years. On several other occasions he performed a

Methylphenidate in Children: Effects upon Cardiorespiratory Function on Exertion

In a yet unpublished study, Werry & Aman gave methylphenidate (0.3 mg/kg) to hyperactive, aggressive children and found that over a seven-hour period, the greatest cardiovascular response was two to three hours after oral ingestion, but that these effects were greatly outweighed by those of digestion after the noon meal. Although there are now data relating to the stimulating effect of methylphenidate on heart rate (Cohen, Douglas, & Morgenstern, 1971; Knights & Hinton, 1969; Sprague, 1972) and, to a lesser extent, blood pressure (Knights & Hinton, 1969), all relate to resting conditions. Yet most of a child's life is characterized by frequent periods of extreme physical exertion. Recently, Sprague & Boileau (1973) conducted a study in which hyperactive children were tested on a treadmill to determine the effect of chronic administration of methylphenidate on cardiorespiratory measures under exertion. The results indicated that the heart-rate increase under the influence of methylphenidate was maintained during exertion, in which, in direct contrast to the resting condition, oxygen consumption was significantly less