Exercise-induced Hemolysis Research Articles

Accelerated Red Blood Cell Turnover Following Extreme Mountain Ultramarathon?

Mountain ultramarathon induces extreme physiological stress for the human body. For instance, a decrease in total hemoglobin mass (Hbmass) due to severe hemolysis is historically suspected. Nevertheless, hematological changes following a 330-km mountain ultramarathon have to date never been investigated. Blood volumes were determined before (pre-) and after (post-) a 330-km race completed by thirteen participants, through the automated carbon monoxide (CO)-rebreathing method. Native and normalized blood viscosity were determined using a cone/plate viscometer at five different speeds (11.25 to 225 s-1). Biomarkers of inflammation, erythropoiesis, and hemolysis were additionally quantified. Following the race, an 18% rise in PV (3338 ± 568 vs. 3928 ± 590 mL; p = 0.001) was observed, while absolute Hbmass (802 ± 102 vs. 833 ± 111 g; p = 0.09) did not change significantly. A decrease in native viscosity was reported at all speeds (p < 0.001) with a significant reduction for normalized viscosity at low to intermediate speeds only (i.e. 11.25, 22.5, and 45 s-1). Marked inflammation was suggested by upregulated interleukin-6 (7.1 ± 8 vs. 16.5 ± 14 ng⋅L-1, p = 0.011) and C-reactive protein levels (12.3 ± 14 vs. 51.6 ± 14 μg⋅mL-1, p = 0.001). Besides, the increased erythropoietin (5.7 ± 3 vs. 12 ± 6 mU⋅mL-1, p = 0.021) and erythroferrone levels (6.5 ± 4 vs. 8.5 ± 4 ng⋅L-1, p = 0.001) may indicate enhanced erythropoiesis. Overall, these findings suggest an enhanced red blood cell turnover, probably triggered by limited exercise-induced hemolysis (although still supported by the decrease in corrected viscosity), likely balanced through accelerated erythropoiesis.

An enhanced label-free proteomics approach for deep-diving into equine plasma proteome, including the discovery of protein biomarkers for strenuous exercise.

Plasma proteins have been a valuable source of biomarkers for clinical uses and for monitoring of the illicit use of prohibited substances or practices in equine sports. We have previously reported the first use of label-free proteomics in profiling equine plasma proteome. This study aimed to refine the method by systematically evaluating various plasma fractionation methods and the use of narrower precursor mass ranges in data-independent acquisition (DIA) mass spectrometry (MS). Tandem fractionations of equine plasma with octanoic acid precipitation followed by solid-phase extraction (SPE) with C4 cartridges provided the largest increase in the number of new proteins identified. The use of two narrow precursor mass ranges of m/z 400-600 and 600-800 in DIA not only identified most proteins detectable by using a single mass range of m/z 350-1500 but also identified ~27% more proteins. The improved method was applied to analyse the plasma proteome of 'postrace' samples which, unlike other samples, had been collected from racehorses soon after racing. Multivariate data analysis has identified upregulation of 14 proteins and downregulation of six proteins in postrace plasma compared with the non-postrace plasma samples. Literature review of these proteins has provided evidence of exercise-induced haemolysis and changes in antioxidant enzyme activities, kinin system, insulin signalling and energy metabolism after strenuous exercise. The improved method has enabled a deeper profiling of the equine plasma proteome and identified the proteins associated with normal physiological changes after racing which are potential confounding factors in the development of a biomarker approach for doping control.

Effect of long-term carnosine/anserine supplementation on iron regulation after a prolonged running session.

Exercise-induced hemolysis, which is caused by metabolic and/or mechanical stress during exercise, is considered a potential factor for upregulating hepcidin. Intramuscular carnosine has multiple effects including antioxidant activity. Therefore, this study aimed to determine whether long-term carnosine/anserine supplementation modulates exercise-induced hemolysis and subsequent hepcidin elevation. Seventeen healthy male participants were allocated to two different groups: participants consuming 1,500 mg/day of carnosine/anserine supplements (n = 9, C+A group) and participants consuming placebo powder supplements (n = 8, PLA group). The participants consumed carnosine/anserine or placebo supplements daily for 30.7 ± 0.4 days. They performed an 80-running session at 70% VO2peak pre-and post-supplementation. Iron regulation and inflammation in response to exercise were evaluated. Serum iron concentrations significantly increased after exercise (p &lt; 0.01) and serum haptoglobin concentrations decreased after exercise in both groups (p &lt; 0.01). No significant differences in these variables were observed between pre-and post-supplementation. Serum hepcidin concentration significantly increased 180 min after exercise in both groups (p &lt; 0.01). The integrated area under the curve of hepcidin significantly decreased after supplementation (p = 0.011) but did not vary between the C+A and PLA groups. Long-term carnosine/anserine supplementation does not affect iron metabolism after a single endurance exercise session.

Characterization of exercise-induced hemolysis in endurance horses.

Exercise-induced hemolysis occurs as the result of intense physical exercise and is caused by metabolic and mechanical factors including repeated muscle contractions leading to capillary vessels compression, vasoconstriction of internal organs and foot strike among others. We hypothesized that exercise-induced hemolysis occurred in endurance racehorses and its severity was associated with the intensity of exercise. To provide further insight into the hemolysis of endurance horses, the aim of the study was to deployed a strategy for small molecules (metabolites) profiling, beyond standard molecular methods. The study included 47 Arabian endurance horses competing for either 80, 100, or 120 km distances. Blood plasma was collected before and after the competition and analyzed macroscopically, by ELISA and non-targeted metabolomics with liquid chromatography-mass spectrometry. A significant increase in all hemolysis parameters was observed after the race, and an association was found between the measured parameters, average speed, and distance completed. Levels of hemolysis markers were highest in horses eliminated for metabolic reasons in comparison to finishers and horses eliminated for lameness (gait abnormality), which may suggest a connection between the intensity of exercise, metabolic challenges, and hemolysis. Utilization of omics methods alongside conventional methods revealed a broader insight into the exercise-induced hemolysis process by displaying, apart from commonly measured hemoglobin and haptoglobin, levels of hemoglobin degradation metabolites. Obtained results emphasized the importance of respecting horse limitations in regard to speed and distance which, if underestimated, may lead to severe damages.

Exercise-induced Hemolysis And Iron Regulation In Response To Mechanical Stress

Hepcidin, a liver derived hormone, plays a role in iron regulation due to decreases in iron absorption and/or iron recycling. Exercise-induced hepcidin secretion is thought to be augmented by increased interleukin-6 (IL-6) and hemolysis (i.e., disruption of red blood cells). However, it is difficult to comprehend the contributions of hemolysis during exercise for hepcidin secretion. PURPOSE: To investigate the impact of exercise-induced hemolysis by a drop jump with concomitant repetitions of mechanical stress on hepcidin response. METHODS: Ten healthy males attended in this study [means ± SD, age: 24 ± 3 yrs, height: 170.6 ± 5.8 cm, body weight: 64.4 ± 7.2 kg]. Participants conducted two trials on different days, consisting of drop jump exercise to induce mechanical stress (DJ trial) or without exercise (CON trial). DJ trial consists of 100 bouts of drop jump from a 60 cm box, and each jump was conducted with their maximal effort. Blood samples were collected before trials, immediately, 1 h, 2 h and 3 h after completion of trials. The timing of blood sampling in CON trial was matched with DJ trial. A p value less than 0.05 was considered statistically significant. RESULTS: Baseline serum ferritin concentration did not significantly differ between DJ (73.1 ± 42.8 ng/mL) and CON trials (65.2 ± 31.6 ng/mL, p = 0.135). Serum iron and myoglobin concentration significantly increased and serum haptoglobin concentrations significantly decreased post-exercise in DJ trial (p < 0.05). Plasma IL-6 concentration did not increase in either trial (p > 0.05). Serum hepcidin concentration significantly increased 3 h after both trials (p < 0.05); however, the relative increase in serum hepcidin concentrations did not differ significantly between DJ and CON trials (77.4 ± 70.6% vs. 39.1 ± 51.5%, p = 0.184). CONCLUSIONS: Hemolysis was occurred following the drop jump exercise, while post-exercise IL-6 and hepcidin elevations were not different between the trials. Mechanical stress-induced hemolysis may not be sufficient to induce hepcidin elevation without IL-6 changes.

Urinalysis Reveals Hemolysis In A World-Class Ultramarathon Runner: A Case Study

PURPOSE: Ultra-endurance running, classified as any distance greater than a marathon (42.2km), is strenuous on the body. These extreme distances may include difficult weather conditions or terrain (e.g., heat, cold, altitude, trails, etc.) and could lead to changes in urine biomarkers resulting from damage to essential organs (e.g., kidney, liver, and heart). The purpose of this study was to determine the effects of running a grueling 161.3km trail race on general characteristics, presence of blood, and other molecules in the urine of an elite ultra-endurance runner (EUR). METHODS: Urine specimens were collected from a 32y male EUR (170cm, 64.5kg, age-ranked 98.7%[ultrasignup.com]), before and after completing the Western States Endurance Run (WSER). Samples were analyzed using 11-parameter urinalysis strips (Med Lab Diagnostics, Laguna Beach, CA) one day pre-race and ~2h post-race. RESULTS: EUR finished the WSER in less than 16 hours. Main findings showed red blood cell (RBC) count increased from 0 to ≥200 cells/μl (indicated hemolysis), bilirubin increased from 0 to 17 mmol/L (biproduct of hemoglobin), and urobilinogen increased from 0 to 3.2 mmol/L (indicated RBC destruction) post-race. Urine proteins and ketone abundance increased while ascorbate decreased post-race. CONCLUSIONS: Elevated urinary levels of red blood cell derivatives post-WSER highlight the formidable hematologic implications of ultramarathon running. Modalities to mitigate this phenomenon as well as an improved understanding of the systemic consequences of and time to recover from this exercise-induced hemolysis are of interest.

Epidemiological, biological and clinical update on exercise-induced hemolysis.

Exercise-induced hemolysis can be conventionally defined as rupture and destruction of erythrocytes during physical exercise. The currently available epidemiologic information attests that a substantial degree of exercise-induced hemolysis is commonplace after short-, medium-, long- and ultra-long distance running, as reflected by significant decrease of serum or plasma haptoglobin and significant increase of plasma concentration (or overall blood content) of free hemoglobin. This paraphysiological intravascular hemolysis is typically mild (average variations of hemolysis biomarkers are usually comprised between 1.2- and 1.8-fold), almost self-limiting (completely resolving within 24-48 hours), with severity depending on athlete population, analytical technique used for detecting intravascular hemolysis, as well as on number, frequency and intensity of ground contacts, but not on running technique. Additional lines of evidence support the notion that both osmotic fragility and membrane structure of erythrocytes are considerably modified during endurance exercise. This fact goes hand in hand with findings that erythrocyte lifespan in runners is approximately 40% shorter than in sedentary controls. Direct mechanical injury caused by forceful ground contacts, repeated muscle contractile activity or vasoconstriction in internal organs are three potential sources of exercise-induced hemolysis, whilst metabolic abnormalities developing while exercising (e.g., hyperthermia, dehydration, hypotonic shock, hypoxia, lactic acidosis, shear stress, oxidative damage, proteolysis, increased concentration of catecholamines and lysolecithin) may actively contribute to trigger, accelerate or amplify this phenomenon. Although no systematic evidence is available, it seems also reasonable to hypothesize that patients bearing erythrocyte disorders may be particularly vulnerable to developing exercise-induced hemolysis.

Intense exercise increases protein oxidation in spleen and liver of mice.

Studies have indicated that sports anemia is mainly associated with intravascular hemolysis induced by exercise. We hypothesized that such exercise-induced hemolysis leads to oxidative damage due to an increase in free iron caused by hematocyte destruction. Thirty-one male ICR mice were randomly divided into 3 groups: a rested control group, an intense-exercise group, and a group rested for 24 hours after intense exercise. The serum haptoglobin level of the intense-exercise group decreased compared with that of the rested control group, suggesting hemolysis. Tissue iron and protein carbonyl levels in the liver were increased after exercise, and the protein carbonyl level in the spleen on the day after exercise was significantly increased compared with that of the resting state. These results suggest that the spleen and liver, where extravascular hemolysis occurs, were subjected to oxidative modification by the free iron, which was released from large numbers of hemocytes that were destroyed due to the intense exercise.

Influence of Artistic Gymnastics on Iron Nutritional Status and Exercise-Induced Hemolysis in Female Athletes

This study evaluates the relationship between body iron losses and gains in artistic gymnastics female athletes. It shows that despite the low iron intake and exercise-induced hemolysis, iron deficiency or iron-deficiency anemia does not occur, but partial changes in the hematological profile do. The hypothesis that gymnasts' nutritional behavior contributes to anemia, which may be aggravated by exercise-induced hemolysis, led to this cross-sectional study, conducted with 43 female artistic gymnasts 6-16 yr old. The control group was formed by 40 nontraining girls, paired by age. Hemogram, serum iron, ferritin, soluble transferrin receptor, haptoglobin, total and fractional bilirubin, Type I urine, and parasitologic and occult fecal blood tests were evaluated. The athletes presented mean hematimetric and serum iron values (p = .020) higher than those of the control group. The bilirubin result discarded any hemolytic alteration in both groups. The haptoglobin results were lower in the athlete group (p = .002), confirming the incidence of exercise-induced hemolysis. Both groups presented low iron intake. The results suggest that artistic gymnastics practice leads to exercise-induced hemolysis and partially changes the hematological profile, although not causing iron deficiency or iron-deficiency anemia, even in the presence of low iron intake.

Exercise-induced hemolysis is caused by protein modification and most evident during the early phase of an ultraendurance race

Whether structural changes of the erythrocyte membrane increase the susceptibility to hemolysis particularly of the relatively older cell population during the early phase of a 216-km ultrarace was tested in six male runners (age 53.6 +/- 10.4 yr, height 175.8 +/- 11.1 cm, body mass 75.9 +/- 8.4 kg). Erythrocyte membrane spectrins were lowest (P < 0.001) after 42 km (75.59 +/- 5.25% of prerace) and increased (P < 0.001) toward 216 km (88.27 +/- 3.37%). Susceptibility to osmotic hemolysis was highest (P < 0.01) after 42 km (107.34 +/- 3.02 mOsm sodium phosphate buffer) with almost identical (P > 0.05) values prerace (97.98 +/- 3.41 mOsm) and postrace (98.61 +/- 3.26 mOsm). Haptoglobin indicated intravascular hemolysis of 9.27 x 10(9) cells/l (P < 0.05) during the initial 84 km. Changes in hematocrit and plasma proteins indicated an estimated total net erythrocyte loss of 3.47 x 10(11) cells/l (P < 0.05) after 21 km. This was compensated by a gain in erythrocytes (P < 0.05) of 3.31 x 10(11) cells/l during the final 132 km. A main effect (P < 0.05) on erythropoietin suggests increased erythropoiesis throughout the race. Exercise-induced hemolysis reflects alterations in erythrocyte membrane spectrins and occurs particularly in the early phase of an ultraendurance race because of a relative older cell population.

Effects of Marathon Running on Platelet Activation Markers

We used the ADVIA 2120 Hematology System (Bayer HealthCare, Diagnostics Division, Tarrytown, NY) to study the effects of vigorous exercise on CBC count, WBC differential, RBC fragmentation, and platelet activation parameters in 32 healthy participants in a 26.2-mile (42.2-km) marathon. The runners demonstrated increases in hematocrit and platelet count consistent with dehydration and leukocytosis indicative of demargination of neutrophils or inflammation secondary to tissue destruction (eg, rhabdomyolysis). The number of RBC fragments was increased after the race ( P = .008), consistent with exercise-induced hemolysis. The mean platelet component, a measure of platelet granularity, was decreased ( P < .0001), and the number of platelet clumps was increased ( P = .0026), providing evidence for in vivo platelet activation during the marathon. By using direct measurement of platelet granularity, our study confirms the in vivo activation of platelets by vigorous exercise and establishes the usefulness of automated cell counters for the assessment of platelet activation and of RBC fragmentation in this setting.

Effects of Marathon Running on Platelet Activation Markers : Direct Evidence for In Vivo Platelet Activation

We used the ADVIA 2120 Hematology System (Bayer HealthCare, Diagnostics Division, Tarrytown, NY) to study the effects of vigorous exercise on CBC count, WBC differential, RBC fragmentation, and platelet activation parameters in 32 healthy participants in a 26.2-mile (42.2-km) marathon. The runners demonstrated increases in hematocrit and platelet count consistent with dehydration and leukocytosis indicative of demargination of neutrophils or inflammation secondary to tissue destruction (eg, rhabdomyolysis). The number of RBC fragments was increased after the race (P = .008), consistent with exercise-induced hemolysis. The mean platelet component, a measure of platelet granularity, was decreased (P < .0001), and the number of platelet clumps was increased (P = .0026), providing evidence for in vivo platelet activation during the marathon. By using direct measurement of platelet granularity, our study confirms the in vivo activation of platelets by vigorous exercise and establishes the usefulness of automated cell counters for the assessment of platelet activation and of RBC fragmentation in this setting.

Blood cell NO synthesis in response to exercise

Nitric oxide (NO) is important for the maintenance of cardiovascular homeostasis and is also involved in immunity and inflammation. The aim of our work was to determine the effects of intense exercise on plasma and blood cell NO handling. Nine voluntary male professional cyclists participated in the study. Blood samples were taken in basal conditions and 3h after finishing a mountain cycling stage. Exercise-induced neutrophilia, lymphopenia, and hemolysis. Plasma and erythrocytes maintained basal nitrite levels, whereas neutrophils and lymphocytes decreased nitrite concentration after intense exercise. Basal iNOS levels and SOD activity were similar in neutrophils and lymphocytes. iNOS levels and SOD activity dropped in neutrophils and rose in lymphocytes after exercise. Arginase activity rose only in lymphocytes. Neutrophil nitrite was correlated with SOD activity and iNOS levels, but not in lymphocytes. iNOS levels were correlated with SOD in both neutrophils and lymphocytes. Intense exercise maintained plasma basal arginine and ornithine concentration, and decreased citrulline concentration. Intense exercise induced important changes in NO handling in neutrophils and lymphocytes, yet the basal picture was maintained in erythrocytes.

Exercise-induced oxidative stress leads hemolysis in sedentary but not trained humans

Intravascular hemolysis is one of the most emphasized mechanisms for destruction of erythrocytes during and after physical activity. Exercise-induced oxidative stress has been proposed among the different factors for explaining exercise-induced hemolysis. The validity of oxidative stress following exhaustive cycling exercise on erythrocyte damage was investigated in sedentary and trained subjects before and after antioxidant vitamin treatment (A, C, and E) for 2 mo. Exercise induced a significant increase in thiobarbituric acid-reactive substance and protein carbonyl content levels in sedentary subjects and resulted in an increase of osmotic fragility and decrease in deformability of erythrocytes, accompanied by signs for intravascular hemolysis (increase in plasma hemoglobin concentration and decrease in haptoglobulin levels). Administration of antioxidant vitamins for 2 mo prevented exercise-induced oxidative stress (thiobarbituric acid-reactive substance, protein carbonyl content) and deleterious effects of exhaustive exercise on erythrocytes in sedentary subjects. Trained subjects' erythrocyte responses to exercise were different from those of sedentary subjects before antioxidant vitamin treatment. Osmotic fragility and deformability of erythrocytes, plasma hemoglobin concentration, and haptoglobulin levels were not changed after exercise, although the increased oxidative stress was observed in trained subjects. After antioxidant vitamin treatment, functional and structural parameters of erythrocytes were not altered in the trained group, but exercise-induced oxidative stress was prevented. Increased percentage of young erythrocyte populations was determined in trained subjects by density separation of erythrocytes. These findings suggest that the exercise-induced oxidative stress may contribute to exercise-induced hemolysis in sedentary humans.

Damage To Erythrocyte Membrane Proteins Causes Hemolysis In Endurance Athletes

There is a wide body of literature that reports erythrocyte hemolysis following various forms of exercise. Whereas the trauma associated with intravascular hemolysis is thought to be the major cause of hemolysis after running, the mechanistic basis for exercise-induced hemolysis has not been thoroughly addressed. PURPOSE The aim of the study was to investigate whether increased fragility of the erythrocyte coincides with structural changes of the erythrocyte membrane. METHODS The impact of exertional endurance stress was investigated in 3 male runners performing a 10K run and 3 others a cross-country marathon (n=6, age; 31.0±6 yrs; height; 1.77±0.06 m, weight; 72.7±8 kg). Pre and post exercise blood samples were collected and analysed for hemoglobin (Hb) and hematocrit concentrations, osmotic fragility, total membrane proteins concentration and SDS/UREA-PAGE separations. RESULTS Osmotic fragility increased after both exercises, with maximum hemolysis increase of 10.39±0.89% in the marathon runners compared to 5.23±0.4% in 10K runners at p < 0.05. The intensity of spectrin bands on SDS-PAGE gels decreased following both exercises, the greater effect being observed in the marathon runners (16.59±1.60%) compared to 10K runners (9.86±0.88%), at p< 0.05. Membrane bound Hb was also observed in two marathon runners. CONCLUSION The results indicate that exercise-induced hemolysis is caused by structural changes to the erythrocyte membrane and that membrane-Hb cross-linking may play a role in the degeneration of erythrocyte membrane.

Damage To Erythrocyte Membrane Proteins Causes Hemolysis In Endurance Athletes

There is a wide body of literature that reports erythrocyte hemolysis following various forms of exercise. Whereas the trauma associated with intravascular hemolysis is thought to be the major cause of hemolysis after running, the mechanistic basis for exercise-induced hemolysis has not been thoroughly addressed. PURPOSE The aim of the study was to investigate whether increased fragility of the erythrocyte coincides with structural changes of the erythrocyte membrane. METHODS The impact of exertional endurance stress was investigated in 3 male runners performing a 10K run and 3 others a cross-country marathon (n=6, age; 31.0±6 yrs; height; 1.77±0.06 m, weight; 72.7±8 kg). Pre and post exercise blood samples were collected and analysed for hemoglobin (Hb) and hematocrit concentrations, osmotic fragility, total membrane proteins concentration and SDS/UREA-PAGE separations. RESULTS Osmotic fragility increased after both exercises, with maximum hemolysis increase of 10.39±0.89% in the marathon runners compared to 5.23±0.4% in 10K runners at p < 0.05. The intensity of spectrin bands on SDS-PAGE gels decreased following both exercises, the greater effect being observed in the marathon runners (16.59±1.60%) compared to 10K runners (9.86±0.88%), at p< 0.05. Membrane bound Hb was also observed in two marathon runners. CONCLUSION The results indicate that exercise-induced hemolysis is caused by structural changes to the erythrocyte membrane and that membrane-Hb cross-linking may play a role in the degeneration of erythrocyte membrane.

Relation between oxidative stress markers and antioxidant endogenous defences during exhaustive exercise

Hydrogen peroxide (H2O2) could induce oxidative damage at long distance from its generation site and it is also an important signalling molecule that induces some genes related to oxidative stress. Our objective was to study the plasma and blood cells capability to detoxify H2O2 after intense exercise and its correlation with oxidative damage. Blood samples were taken from nine professional cycling, participating in a mountain stage, under basal conditions and 3 h after the competition. Catalase and glutathione peroxidase activities decreased (40 and 50% respectively) in neutrophils after the cycling stage, while glutathione peroxidase increased (87%) in lymphocytes. Catalase protein levels and catalase specific activity maintained basal values after the stage in plasma. Catalase protein levels decreased (48%) in neutrophils and its specific activity increased up to plasma values after exercise. Myeloperoxidase (MPO) increased (39%) in neutrophils after the cycling stage. Exercise-induced hemolysis and lymphopenia inversely correlated with cellular markers of oxidative stress. Plasma malondialdehyde (MDA) directly correlated with neutrophil MPO activity and erythrocytes MDA. Intense exercise induces oxidative damage in blood cells as erythrocytes and lymphocytes, but not in neutrophils.

Short-term effects of prolonged strenuous endurance exercise on the level of haematocrit in amateur cyclists.

Knowledge is sparse about the extent of potential dehydration due to prolonged strenuous cycling and its haematological acute effects on the haematocrit (Hct) in study populations credibly not taking any kind of doping. With increasing training load levels of Hct and haemoglobin (Hb) decrease in both amateurs and professionals as a long-term consequence due to expanded plasma volume (PV). On a short-term basis, however, counteracting dehydration potentially brought about by endurance exercise may cause a rise in Hct bringing competitive cyclists into conflict with the current condition regulations and Hct cut-off of 50 % set by the International Cycling Union (UCI) in its fight against erythropoietin (rhEPO) doping. On the other hand adequate and sufficient fluid substitution being substantial for a successful endurance performance should prevent any pronounced Hct rises. To study the haematological acute effects of prolonged strenuous cycling we measured Hct, Hb, red blood cell (RBC) count and plasma protein in a reliably 'clean' population of 38 well-trained male amateur cyclists before, immediately after and one day after an extraordinary ultramarathon. The pre-race levels of Hct, Hb and RBC count were placed in the lower range of normal distribution and well below the Hct cut-off limit of the UCI. Immediately post-exercise the mean levels of Hct, Hb, RBC count and protein remained unchanged. One day after race, however, all four parameters significantly dropped by 3 %, 6.7 %, 6.5 %, 9.9 % respectively (p < 0.001), indicating marked post-exercise PV expansion. The calculated percentage increase in PV was 11.9 %. No evidence for coexisting exercise-induced haemolysis was found. Our study shows that in "clean, rhEPO-free" amateur cyclists who involve in strenuous marathon cycling the haematological short-term effects of extraordinary marathon cycling consist in considerable PV expansion making Hct values fall on the following day. The findings - gained from amateurs though - suggest that despite all its disadvantages the UCI Hct cut-off represents an appropriate means to discourage from excessive rhEPO doping at least as long as the available direct methods for detecting this kind of misuse are not yet applied by the international sports federations.

Exercise-induced Fragmentation Hemolysis

Exercise-induced Fragmentation Hemolysis

Haemolytic effects of 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.