1. It has been suggested that the physiological consequences of strenuous exercise are analogous to those of the acute-phase response. 2. In 70 male and 20 female competitive distance runners, a marked, but transient, neutrophil leucocytosis occurred immediately after these athletes completed a standard (42 km) marathon race. Concomitant significant increases were noted in the plasma cortisol levels, creatine kinase activity, C-reactive protein level, total protein level and albumin level (P less than 0.01). 3. The plasma fibrinogen, C-reactive protein and total protein concentrations were markedly increased both 24 h and 48 h after exercise (P less than 0.01). The serum haptoglobin level was significantly decreased after exercise (P less than 0.01), and increased 48 h later (P less than 0.05). There was no change in the serum iron level, total iron-binding capacity, per cent saturation of transferrin and serum ferritin level. 4. A significant increase in interleukin-1-type activity was demonstrated immediately and 24 h after exercise (P less than 0.01). 5. It is concluded that the metabolic sequelae of sustained exercise are similar, but not analogous, to the acute-phase response, and interleukin-1, probably plays a significant role in linking the haematological and immunological changes observed after sustained strenuous exercise.

1. Exercise-induced haemolysis has been implicated in the sub-optimal iron status of endurance-trained athletes. Accordingly, erythrocyte survival studies using 51Cr were performed on male and female distance runners (n = 20) and sedentary control subjects (n = 10) in order to determine whether the rate of erythrocyte destruction was altered as a consequence of repetitive exercise training. 2. The chromium half-disappearance time of the male (25.4 +/- 3.6 days, mean +/- SD) but not the female (28.3 +/- 4.6 days) athletes was significantly lower than that of the male (33.1 +/- 4.5 days) and female (32.3 +/- 2.6 days) control subjects (P less than 0.01). The mean erythrocyte lifespan of the male and female distance runners (67.2 +/- 22.2 and 72.4 +/- 26.0 days, respectively) was significantly shorter than that of the non-exercising male and female subjects (113.4 +/- 31.0 and 114.1 +/- 29.0 days, respectively) (P less than 0.01). 3. There was no correlation between the mean erythrocyte lifespan and the haemoglobin concentration, serum ferritin levels, body mass, weekly training distance, number of years running or daily protein intake. The mean cell volume and reticulocyte count measured in the same athletes before and after completing a standard 42 km marathon race were within the normal range, whereas the plasma haemoglobin levels were elevated (77.0 +/- 50.5 mg/l) and the serum haptoglobin levels were decreased (0.89 +/- 0.4 g/l) at rest, with a further significant decrease after running (0.69 +/- 0.4 g/l) in the latter measurement (P less than 0.05). 4. It is concluded that the demonstrated increase in erythrocyte turnover may be sufficient to precipitate an iron deficiency in endurance athletes when dietary intake or absorption does not meet the accelerated erythropoietic demands.

We measured serum concentrations of thiamin, riboflavin, nicotinic acid, pyridoxine, folate, cyanocobalamin, ascorbic acid, retinol, tocopherol, zinc, magnesium, copper, iron, and ferritin as well as hemoglobin, hematocrit, percentage transferrin saturation, and total iron-binding capacity in athletes who ingested a multivitamin and mineral supplement for 3 mo. All blood variables were normal and except for pyridoxine and riboflavin there were no significant changes in the blood concentrations of any other vitamins or minerals measured. This may have been due to variable interactions between the vitamins and minerals in the supplement that prevented their being adequately absorbed. There were no signs or symptoms of serious toxic side effects. We conclude that multivitamin and mineral supplementation was without any measurable ergogenic effect and that such supplementation is unnecessary in athletes ingesting a normal diet.

In order to critically define the apparently widespread condition 'sports anemia', the red cell indices and iron status of male distance runners and triathletes, and female distance runners and ballet dancers were compared to non-exercising controls of both sexes. The mean hemoglobin (Hb) levels of all groups were within the normal ranges and there was no difference between the athletic and control groups of each sex. The mean serum ferritin (SF) concentration of the male distance runners (79.8 micrograms/l) was significantly lower than that of the triathletes (123.5 micrograms/l) and controls (138.3 micrograms/l). Iron deficiency (SF less than 12 micrograms/l, % saturation less than 18%) was evident in 3.3% and 5% of the male and female runners respectively, and 3.3% of the ballet dancers. Iron deficiency anemia (abnormal red cell indices and iron status) occurred in only 1.7% and 3.3% of the male and female distance runners respectively, and 3.3% of the dancers. However, 7 (11.7%) each of the male and female distance runners and 6 (20.0%) of the ballet dancers recorded hemoglobin values lower than the normal range of 140 g/l and 120 g/l for males and females respectively. This anomaly can be explained by a significantly expanded plasma volume in endurance-trained individuals, causing a 'pseudoanemia'. We conclude therefore that athletes are at no greater risk for developing a frank anemia than the non-exercising population, and that the term 'sports anemia' is misleading, as it does not describe a specific clinical entity.

There is limited scientific justification for the widespread use of vitamin and mineral supplements by athletes. We used a 9-mo, placebo-controlled crossover study design to determine whether a multivitamin and mineral supplement influenced the athletic performance of 30 competitive male athletes. At 0, 3, 6, and 9 mo the runners performed a progressive treadmill test to volitional exhaustion for measurement of maximal oxygen consumption, peak running speed, blood lactate turnpoint, and peak postexercise blood lactate level. Running time in a 15 km time trial was also measured. None of these variables was influenced by 3 mo of active supplementation. We conclude that 3 mo of multivitamin and mineral supplementation was without any measurable ergogenic effect.

To characterize the so-called pseudoanaemia of endurance-trained athletes, the plasma volume (PV), red cell volume (RCV) and total blood volume (TBV) of 12 male and 12 female athletes and 5 male and 5 female nonexercising controls were measured using 125I-labelled human serum albumin and 51Cr-labelled erythrocytes. The mean PV of the male athletes (52.8 ml.kg-1) was 37.5% higher than that of the controls (38.4 ml.kg-1), while the 18.1% increase measured in the female runners (51.5 ml.kg-1) over the controls (43.6 ml.kg-1) was a novel observation. Although the RCV was significantly greater (34.7%) in male athletes (32.6 ml.kg-1 vs 24.2 ml.kg-1 in the controls), a similar elevation (3.6%) was not found in the female athletes (25.9 ml.kg-1) compared to the sedentary women (22.8 ml.kg-1). This could have been due to iron-limited erythropoiesis because the RCV of the female athletes defined as clinically anaemic was markedly lower that of the nonanaemic women (P less than 0.05). The elevated plasma protein mass and concentration measured in the athletes partly accounted for their expanded PV. It was concluded that the decreased blood haemoglobin levels reported in the endurance athletes was largely a dilutional effect.

Erythropoietic adaptations involving the oxygen dissociation curve (ODC) and erythropoietin production have been implicated in the etiology of reduced blood haemoglobin concentrations in sportspersons (known as sports anaemia). A significant increase in the half-saturation pressure indicating a right-shift in the ODC was measured in 34 male [25.8-27.4 mmHg (3.44-3.65 kPa)] and 16 female (25.8-27.7 mmHg (3.44-3.69 kPa)] trained distance runners (P less than 0.01 for both genders) after completing a standard 42-km marathon. Erythrocyte 2,3-diphosphoglycerate concentrations measured concurrently were unaltered by exercise, although consistently higher in the female compared to the male athletes (P less than 0.05). The serum erythropoietin (EPO) concentrations of 15 male triathletes (26.3 U.ml-1) were significantly lower than those of 45 male distance runners (31.6 U.ml-1; P less than 0.05). However, the mean serum EPO concentrations of male and female athletes engaged in a variety of sports were not different from those of sedentary control subjects of both sexes (26.5-35.3 U.ml-1). Furthermore, the serum EPO concentrations were unaltered after prolonged strenuous exercise in 20 male marathon runners. These data suggest that the haematological status of these endurance athletes is in fact normal and that the observed shift in the ODC, while providing a physiological advantage during exercise, has no measurable effect on the erythropoietic drive.

In order to determine whether dietary inadequacies can explain the sub-optimal iron status widely documented in endurance-trained athletes, the food intake records of Fe-deficient and Fe-replete distance runners and non-exercising controls of both sexes were analysed. In all the male study groups the mean dietary Fe intake met the recommended dietary allowances (RDA; > 10 mg/d (US) Food and Nutrition Board, 1989). However, both female athletes and controls failed to meet the RDA with regard to Fe (< 15 mg/d) and folate (< 200 μg/d). There was no difference in the total Fe intakes of Fe-deficient and Fe-replete athletes and the controls of each sex. However, Fe-deficient male runners, but not female runners, consumed significantly less haem-Fe (P= 0.048) than their comparative groups. This suggests that the habitual consumption of Fe-poor diets is a factor in the aetiology of athletes' Fe deficiency.