Post-race Plasma Research Articles

Completing a 4,486 km Multi-stage Ultramarathon Increases Arterial Stiffness and Alters Circulating Factors That Cause Endothelial Cell Dysfunction

Background: Guideline-based levels of aerobic exercise can improve vascular function, in part by decreasing arterial stiffness and oxidative stress, and increasing nitric oxide bioavailability. However, results from single-stage ultramarathons and ultra-endurance feats in modalities such as biking or triathlons suggest that excessive levels of aerobic exercise may impair vascular function. Some athletes will complete multi-day ultra-endurance events. One such example is the TransEurope FootRace (TEFR), a transcontinental ultramarathon in which participants cover 4,486 km in 64 days. However, the impact of this multi-stage ultramarathon on vascular function is unknown. Purpose: Here, we tested the hypotheses that completing the TEFR would increase arterial stiffness measured in vivo and alter circulating factors that increase reactive oxygen species (ROS) production and reduce the activation of endothelial nitric oxide synthase (eNOS) ex vivo. Methods: Data were obtained from 29 men and 1 woman (48±11 years of age) before and within 10 days of completing the TEFR. Arterial stiffness was assessed as carotid-femoral pulse wave velocity measured via MRI. Human aortic endothelial cells (HAECs) in culture were exposed to 10% subject plasma, then stained with florescent probes to detect basal ROS production (CellROX). Protein concentrations of phosphorylated(p)‐eNOS(S1177), a primary activation site of eNOS, were determined in the cultured HAECs via WES. Protein expression was normalized to total protein in the sample. P-eNOS relative to total protein was compared with total eNOS relative to total protein to determine activated eNOS. Results: Completing the TEFR caused a clinically significant 31% increase in carotid-femoral pulse wave velocity (pre-race: 610±37 cm/s, post-race: 800±99 cm/s; p=0.0374). ROS production increased by 40% in HAECs exposed to post-race plasma compared with pre-race plasma (pre-race: 1308±86 AU, post-race: 1836±131 AU; p<0.0001). P-eNOS(S1177) decreased by 71% in HAECs after compared with before the race (pre-race: 0.080±0.038 AU; post-race: 0.023±0.005 AU; p=0.0047), whereas total eNOS was unchanged (pre-race: 1.646±0.328 AU, post-race 1.634±0.6533 AU, p=0.9137), suggesting a marked decrease in eNOS activation after the race. Conclusions: These findings indicate that completing a 64-day, 4,486 km ultramarathon increases arterial stiffness and changes factors in the circulation that increase ROS production and decrease eNOS activation, denoting reduced endothelial cell functioning. Performing this level of prolonged, strenuous physical exercise impairs vascular function in healthy highly trained adults. K01HL153326; SCHU 2514/1-1; SCHU 2514/1-2. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

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.

Soluble Interleukin-6 Receptor Regulates Interleukin-6-Dependent Vascular Remodeling in Long-Distance Runners.

Little is known about the effects of training load on exercise-induced plasma increase of interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) and their relationship with vascular remodeling. We sought to evaluate the role of sIL 6R as a regulator of IL-6-induced vascular remodeling. Forty-four male marathon runners were recruited and allocated into two groups: low-training (LT, <100 km/week) and high-training (HT, ≥100 km/week), 22 athletes per group. Twenty-one sedentary participants were used as reference. IL-6, sIL-6R and sgp130 levels were measured in plasma samples obtained before and immediately after finishing a marathon (42.2-km). Aortic diameter was measured by echocardiography. The inhibitory effect of sIL-6R on IL-6-induced VSMC migration was assessed using cultured A7r5 VSMCs. Basal plasma IL-6 and sIL-6R levels were similar among sedentary and athlete groups. Plasma IL-6 and sIL-6R levels were elevated after the marathon, and HT athletes had higher post-race plasma sIL-6R, but not IL-6, level than LT athletes. No changes in sgp130 plasma levels were found in LT and HT groups before and after running the marathon. Athletes had a more dilated ascending aorta and aortic root than sedentary participants with no differences between HT and LT athletes. However, a positive correlation between ascending aorta diameter and plasma IL-6 levels corrected by training load and years of training was observed. IL-6 could be responsible for aorta dilation because IL-6 stimulated VSMC migration in vitro, an effect that is inhibited by sIL-6R. However, IL-6 did not modify cell proliferation, collagen type I and contractile protein of VSMC. Our results suggest that exercise induces vascular remodeling. A possible association with IL-6 is proposed. Because sIL-6R inhibits IL-6-induced VSMC migration, a possible mechanism to regulate IL-6-dependent VSMC migration is also proposed.

Ultramarathon Plasma Metabolomics: Phosphatidylcholine Levels Associated with Running Performance.

The purpose of this study was to identify plasma metabolites associated with superior endurance running performance. In 2016, participants at the Western States Endurance Run (WSER), a 100-mile (161-km) foot race, underwent non-targeted metabolomic testing of their post-race plasma. Metabolites associated with faster finish times were identified. Based on these results, runners at the 2017 WSER underwent targeted metabolomics testing, including lipidomics and choline levels. The 2017 participants’ plasma metabolites were correlated with finish times and compared with non-athletic controls. In 2016, 427 known molecules were detected using non-targeted metabolomics. Four compounds, all phosphatidylcholines (PCs) were associated with finish time (False Discovery Rate (FDR) < 0.05). All were higher in faster finishers. In 2017, using targeted PC analysis, multiple PCs, measured pre- and post-race, were higher in faster finishers (FDR < 0.05). The majority of PCs was noted to be higher in runners (both pre- and post-race) than in controls (FDR < 0.05). Runners had higher choline levels pre-race compared to controls (p < 0.0001), but choline level did not differ significantly from controls post-race (p = 0.129). Choline levels decreased between the start and the finish of the race (p < 0.0001). Faster finishers had lower choline levels than slower finishers at the race finish (p = 0.028).

Metabolite Shifts Induced by Marathon Race Competition Differ between Athletes Based on Level of Fitness and Performance: A Substudy of the Enzy-MagIC Study.

This study compared metabolite shifts induced by training for, participation in, and recovery from a marathon race competition among athletes divided into three groups based on fitness (relative maximum oxygen uptake (VO2max)) and performance levels (net running time). Plasma samples from 76 male runners participating in the Munich Marathon were analyzed for metabolite shifts using a targeted metabolomics panel. For the entire cohort of runners, pronounced increases were measured immediately after the race for plasma concentrations of acylcarnitines (AC), the ratio (palmitoylcarnitine + stearoylcarnitine)/free carnitine that is used as a proxy for the activity of the mitochondrial enzyme carnitine palmitoyltransferase, and arginine-related metabolites, with decreases in most amino acids (AA) and phospholipids. Plasma levels of AA and phospholipids were strongly increased 24 and 72 h post-race. Post-race plasma concentrations of AC and arginine-related metabolites were higher in the low compared to top performers, indicating an accumulation of fatty acids and a reliance on protein catabolism to provide energy after the marathon event. This study showed that marathon race competition is associated with an extensive and prolonged perturbation in plasma metabolite concentrations with a strong AC signature that is greater in the slower, less aerobically fit runners. Furthermore, changes in the arginine-related metabolites were observed.

Maintained Hydration Status After a 24-h Winter Mountain Running Race Under Extremely Cold Conditions.

Background: To date, no study has examined the hydration status of runners competing in a 24-h winter race under extremely cold environmental conditions. Therefore, the aim was to examine the effect of a 24-h race under an average temperature of -14.3°C on hydration status.Methods: Blood and urine parameters and body mass (BM) were assessed in 20 finishers (women, n = 6; men, n = 14) pre- and post-race.Results: Five (25%) ultra-runners had lower pre-race plasma sodium [Na+] and 11 (52%) had higher pre-race plasma potassium [K+] values than the reference ranges. Post-race plasma [Na+], plasma osmolality, urine osmolality and urine specific gravity remained stable (p > 0.05). The estimated fluid intake did not differ (p > 0.05) between women (0.30 ± 0.06 L/h) and men (0.46 ± 0.21 L/h). Runners with a higher number of completed ultra-marathons (r = -0.50, p = 0.024) and higher number of training kilometers (r = -0.68, p = 0.001) drank less than those with lower running experience. Pre-race and post-race plasma [Na+] were related to plasma osmolality (r = 0.65, p = 0.002, r = 0.69, p < 0.001, respectively) post-race, but not to fluid intake (p > 0.05). BM significantly decreased post-race (p = 0.002) and was not related to plasma [Na+] or fluid intake (p > 0.05). Post-race hematocrit and plasma [K+] decreased (p < 0.001) and transtubular potassium gradient increased (p = 0.008). Higher pre-race plasma [K+] was related to higher plasma [K+] loss post-race (p = -0.85, p < 0.001).Conclusion: Hydration status remained stable despite the extremely cold winter weather conditions. Overall fluid intake was probably sufficient to replenish the hydration needs of 24-h runners. Current recommendations may be too high for athletes competing in extremely cold conditions.

A randomized controlled trial of manual therapy and pneumatic compression for recovery from prolonged running – an extended study

ABSTRACTManual therapy (MT) and intermittent pneumatic compression (IPC) are recovery methods used by endurance athletes with little evidence supporting effectiveness. This randomized controlled trial evaluated effectiveness of four daily post-race treatments of a specific MT protocol and IPC compared with supine rest on recovery following an ultramarathon among 56 ultramarathoners. Groups were comparable across all characteristics examined, including post-race plasma creatine kinase concentration. Subject completed timed 400 m runs before the race and on days three, five, seven and 14 post- race, and also provided muscle pain and soreness ratings and fatigue scores immediately before and after treatments, and during the 14 days post- race. Daily subjective measures and 400 m run times were not improved by either treatment, but both treatments reduced (p < .05) muscular fatigue scores acutely after treatment following the race and on post-race day 1, and MT improved (p < .05) muscle pain and soreness acutely following the race.

Description of Three Female 24-h Ultra-Endurance Race Winners in Various Weather Conditions and Disciplines.

A The incidence of exercise-associated hyponatremia (EAH) is higher in women than in men. We present three cases of a very mild post-race EAH in female winners of three 24-h ultra races in various weather conditions and disciplines with post-race plasma sodium [Na⁺] levels of 134 mM (Case 1), 133 mM (Case 2) and 134 mM (Case 3). Moreover, Case 1 and Case 2 showed elevated creatine kinase concentrations of >10,000 U/l with an absence of renal function abnormality. The common characteristics were female sex, veteran recreational category, long race experience in the particular sports discipline, excellent race performance, similar total weekly training hours and the presence of luteal phase of the menstrual cycle during the race. Hematocrit and hemoglobin decreased and post-race K⁺/Na⁺ ratio in urine increased in all three cases. In addition, an increased body mass and a decreased urine specific gravity and urine osmolality suggested over-drinking in Case 1. A decrease in the glomerular filtration rate and creatine clearance accompanied by an increase in urine [Na⁺] may contribute to fluid overload in Cases 2 and 3. Furthermore, urine osmolality reached a level indicating antidiuretic hormone secretion in all the present cases. Therefore, we recommend that race medical personnel should not forget to look for EAH even in fast and experienced female athletes and during races in different environmental conditions.

Reported Hydration Beliefs and Behaviors without Effect on Plasma Sodium in Endurance Athletes.

Purpose: Little information is available on the association of hydration beliefs and behaviors in endurance athletes and exercise-associated hyponatremia (EAH). The aim of the present study was to determine hydration beliefs and behaviors in endurance athletes.Method: A 100 and 38 recreational athletes [107 mountain bikers (MTBers) and 31 runners] competing in seven different endurance and ultra-endurance races completed pre- and post-race questionnaires, and a subgroup of 113 (82%) participants (82 MTBers and 31 runners) also provided their blood samples.Result: More than half of the participants had some pre-race (59%), mid-race (58%), and post-race (55%) drinking plan. However, the participants simultaneously reported that temperature (66%), thirst (52%), and plan (37%) affected their drinking behavior during the race. More experienced (years of active sport: p = 0.002; number of completed races: p < 0.026) and trained (p = 0.024) athletes with better race performance (p = 0.026) showed a more profound knowledge of EAH, nevertheless, this did not influence their planned hydration, reported fluid intake, or post-race plasma sodium. Thirteen (12%) hyponatremic participants did not differ in their hydration beliefs, race behaviors, or reported fluid intake from those without post-race EAH. Compared to MTBers, runners more often reported knowledge of the volumes of drinks offered at fluid stations (p < 0.001) and information on how much to drink pre-race (p < 0.001), yet this was not associated with having a drinking plan (p > 0.05). MTBers with hydration information planned more than other MTBers (p = 0.004). In comparison with runners, more MTBers reported riding with their own fluids (p < 0.001) and planning to drink at fluid stations (p = 0.003). On the whole, hydration information was positively associated with hydration planning (n = 138) (p = 0.003); nevertheless, the actual reported fluid intake did not differ between the group with and without hydration information, or with and without a pre-race drinking plan (p > 0.05).Conclusion: In summary, hydration beliefs and behaviors in the endurance athletes do not appear to affect the development of asymptomatic EAH.

Pre-race characteristics and race performance in hyponatremic and normonatremic finishers of Czech ultra-races

Background: Exercise-associated hyponatremia (EAH) is used to describe hyponatremia occurring during or up to 24 hours after physical activity. Objective: The aim of the study was to compare pre-race characteristics, race performance and plasma sodium [Na+] levels of hyponatremic and normonatremic ultra-endurance athletes and chosen variables in all finishers (N = 138). We assessed age, gender, club membership, pre-race training history and experience, pre-race body mass and body mass index (BMI) in 138 finishers of ultra-races (stage mountain bikers, 24 hours mountain bikers, 24 hours ultra-runners and 100 km ultra-runners) and post-race plasma [Na+] in a subgroup of 113 ultra-athletes. Methods: The 138 participants completed a pre-race questionnaire survey and underwent body mass measurement, of those, 113 provided blood samples pre and post-race. Results: There were no group differences between hyponatremic and normonatremic ultra-athletes in age, gender, club membership, prerace BMI, regular training, experience or race placement. Pre-race body mass and BMI related to race placement in the normonatremic group (r = .30, p < .01; r = .43, p < .01). Faster finishers were older (r = –.28, p = .001) and more experienced (r = –.19, p = .02) than slower finishers (N = 138). Lower pre-race body mass and BMI (r = .28, p < .01; r = .49, p < .001) was associated with lower absolute order; however, did not related to age (N = 138). A higher weekly training volume was associated with a lower pre-race body mass (r = –.49, p < .01) in female racers; however, it did not relate to pre-race BMI (r = –.21, p = .41) or race placement (r = –.20, p = .56). Conclusion: Pre-race characteristics did not distinguish those finishers developing EAH from those not developing EAH

Pre- and Post-Race Hydration Status in Hyponatremic and Non-Hyponatremic Ultra-Endurance Athletes.

The monitoring of body mass (BM), plasma sodium concentration ([Na⁺]) and urinary specific gravity (Usg) are commonly used to help detect and prevent over- or dehydration in endurance athletes. We investigated pre-and post-race hydration status in 113 amateur 24-h ultra-runners, 100-km ultra-runners, multi-stage mountain bikers and 24-h mountain bikers, which drank ad libitum without any intervention and compared results of hyponatremic and non-hyponatremic finishers. On average, pre-race plasma [Na⁺] and both pre- and post-race levels of Usg and BM were not significantly different between both groups. However, nearly 86% of the post-race hyponatremic (exercise-associated hyponatremia, EAH) and 68% of the normonatremic (non-EAH) ultra-athletes probably drank prior the race greater volumes than their thirst dictated regarding to individual pre-race Usg levels. Fluid intake during the race was equal and was not related to plasma [Na⁺], Usg or BM changes. A significant decrease in post-race plasma [Na⁺], BM and an increasement in post-race Usg was observed in EAH and non-EAH finishers. Moreover, pre-race plasma [Na⁺] was inversely associated with post-race percentage change in plasma [Na⁺], and pre-race Usg and urinary [Na⁺] with percentage change in Usg in both groups with and without post-race EAH. Thirteen (11.5%) finishers developed post-race EAH (plasma [Na⁺] < 135 mM). The incidence of EAH in ultra-endurance athletes competing in the Czech Republic was higher than reported previously.

Sodium Intake During an Ultramarathon Does Not Prevent Muscle Cramping, Dehydration, Hyponatremia, or Nausea.

BackgroundUltramarathon runners commonly believe that sodium replacement is important for prevention of muscle cramping, dehydration, hyponatremia, and nausea during prolonged continuous exercise. The purpose of this study was to measure total sodium intake to determine if these beliefs are supported.MethodsParticipants of a 161-km ultramarathon (air temperature reaching 39 °C) provided full dietary information during the race, underwent body weight measurements before and after the race, completed a post-race questionnaire about muscle cramping and nausea or vomiting during the race, and had post-race plasma sodium concentration measured.ResultsAmong 20 finishers providing dietary data, mean (±SD) total sodium intake was 13,651 ± 8444 mg (range 2541–38,338 mg), and sodium in food and drink accounted for 66 % of the sodium when averaged across subjects (range 34–100 %). Sodium intake rates were similar when comparing the 10 % of subjects who were hyponatremic with those who were not hyponatremic, the 39 % with muscle cramping or near cramping with those without cramping, and the 57 % who reported having symptoms of nausea or vomiting with those without these symptoms. Weight change between race start and finish was significantly related to rate of sodium intake (r = 0.49, p = 0.030) and total sodium intake (r = 0.53, p = 0.016), but the maximum weight loss among those taking the least total sodium (<4400 mg total sodium during the race) was 4–5 % below the weight measured immediately pre-race.ConclusionsExercise-associated muscle cramping, dehydration, hyponatremia, and nausea or vomiting during exercise up to 30 h in hot environments are unrelated to total sodium intake, despite a common belief among ultramarathon runners that sodium is important for the prevention of these problems.

Rhabdomyolysis and exercise-associated hyponatremia in ultra-bikers and ultra-runners.

BackgroundExercise-associated hyponatremia (EAH), rhabdomyolysis and renal failure appear to be a unique problem in ultra-endurance racers.MethodsWe investigated the combined occurrence of EAH and rhabdomyolysis in seven different ultra-endurance races and disciplines (i.e. multi-stage mountain biking, 24-h mountain biking, 24-h ultra-running and 100-km ultra-running).ResultsTwo (15.4 %) ultra-runners (man and woman) from hyponatremic ultra-athletes (n = 13) and four (4 %) ultra-runners (four men) from the normonatremic group (n = 100) showed rhabdomyolysis following elevated blood creatine kinase (CK) levels > 10,000 U/L without the development of renal failure and the necessity of a medical treatment. Post-race creatine kinase, plasma and urine creatinine significantly increased, while plasma [Na+] and creatine clearance decreased in hyponatremic and normonatremic athletes, respectively. The percentage increase of CK was higher in the hyponatremic compared to the normonatremic group (P < 0.05). Post-race CK levels were higher in ultra-runners compared to mountain bikers (P < 0.01), in faster normonatremic (P < 0.05) and older and more experienced hyponatremic ultra-athletes (P < 0.05). In all finishers, pre-race plasma [K+] was related to post-race CK (P < 0.05).ConclusionsHyponatremic ultra-athletes tended to develop exercise-induced rhabdomyolysis more frequently than normonatremic ultra-athletes. Ultra-runners tended to develop rhabdomyolysis more frequently than mountain bikers. We found no association between post-race plasma [Na+] and CK concentration in both hypo- and normonatremic ultra-athletes.

The prevalence of exercise-associated hyponatremia in 24-hour ultra-mountain bikers, 24-hour ultra-runners and multi-stage ultra-mountain bikers in the Czech Republic.

BackgroundTo assess the prevalence of exercise-associated hyponatremia (EAH) in two 24-hour mountain bike (MTB) (R1,R2), one 24-hour running (R3) and one multi-stage MTB (R4) races held in the Czech Republic in a cluster of four cross-sectional studies.MethodsIn 27 ultra-mountain bikers (ultra-MTBers), 12 ultra-runners, and 14 multi-stage MTBers, fluid intake, changes (Δ) in body mass, hematocrit, plasma volume, plasma [Na+], plasma [K+], plasma osmolality, urine [Na+], urine [K+], urine specific gravity, urine osmolality, K+/Na+ ratio in urine, transtubular potassium gradient and glomerular filtration rate were measured and calculated. The use of non-steroidal anti-inflammatory drugs and symptoms of EAH were recorded using post-race questionnaires.ResultsOf the 53 finishers, three (5.7%) developed post-race EAH, thereof one (3.7%) ultra-MTBer, one (8.3%) ultra-runner and one (7.1%) multi-stage MTBer. Plasma [Na+] decreased significantly (p < 0.001) only in R4. Urine osmolality (R1, R3, R4 p < 0.001; R2 p < 0.05) and glomerular filtration rate (p < 0.001) increased, and body mass decreased in all races (p < 0.05). Δ body mass was inversely related to the number of kilometers achieved (p < 0.001) in R2 where better ultra-MTBers tended to lose more weight. Δ body mass (p < 0.001) and %Δ body mass (p = 0.05) were positively related to lower post-race plasma [Na+] in R3 that was associated with increased loss in body mass. Fluid intake was positively related to race performance in R1 and R2 (R1: p = 0.04; R2: p = 0.01) where ultra-MTBers in R1 and R2 who drank more finished ahead of those who drank less. Post-race plasma [Na+] was negatively associated with race performance in ultra-MTBers in R2 (p < 0.05), similarly ultra-runners in R3 (p < 0.05) where finishers with more kilometres had lower post-race plasma [Na+].ConclusionsThe prevalence of EAH in the Czech Republic was no higher compared to existing reports on ultra-endurance athletes in other countries. Lower plasma [Na+] and development of EAH may be attributed to overdrinking, a pituitary secretion of vasopressin, an impaired mobilization of osmotically inactive sodium stores, and/or an inappropriate inactivation of osmotically active sodium.

Changes in foot volume, body composition, and hydration status in male and female 24-hour ultra-mountain bikers

BackgroundThe effects of running and cycling on changes in hydration status and body composition during a 24-hour race have been described previously, but data for 24-hour ultra-mountain bikers are missing. The present study investigated changes in foot volume, body composition, and hydration status in male and female 24-hour ultra-mountain bikers.MethodsWe compared in 49 (37 men and 12 women) 24-hour ultra-mountain bikers (ultra-MTBers) changes (Δ) in body mass (BM). Fat mass (FM), percent body fat (%BF) and skeletal muscle mass (SM) were estimated using anthropometric methods. Changes in total body water (TBW), extracellular fluid (ECF) and intracellular fluid (ICF) were determined using bioelectrical impedance and changes in foot volume using plethysmography. Haematocrit, plasma [Na+], plasma urea, plasma osmolality, urine urea, urine specific gravity and urine osmolality were measured in a subgroup of 25 ultra-MTBers (16 men and 9 women).ResultsIn male 24-hour ultra-MTBers, BM (P < 0.001), FM (P < 0.001), %BF (P < 0.001) and ECF (P < 0.05) decreased whereas SM and TBW did not change (P > 0.05). A significant correlation was found between post-race BM and post-race FM (r = 0.63, P < 0.001). In female ultra-MTBers, BM (P < 0.05), %BF (P < 0.05) and FM (P < 0.001) decreased, whereas SM, ECF and TBW remained stable (P > 0.05). Absolute ranking in the race was related to Δ%BM (P < 0.001) and Δ%FM in men (P < 0.001) and to Δ%BM (P < 0.05) in women. In male ultra-MTBers, increased post-race plasma urea (P < 0.001) was negatively related to absolute ranking in the race, Δ%BM, post-race FM and Δ%ECF (P < 0.05). Foot volume remained stable in both sexes (P > 0.05).ConclusionsMale and female 24-hour ultra-MTBers experienced a significant loss in BM and FM, whereas SM remained stable. Body weight changes and increases in plasma urea do not reflect a change in body hydration status. No oedema of the lower limbs occurred.

Control of the misuse of testosterone in castrated horses based on an international threshold in plasma.

Testosterone is an endogenous steroid produced primarily in the testes. Trace levels of testosterone are found in urine samples from geldings, as testosterone is also secreted by the adrenal. An international threshold of free and conjugated testosterone in urine (20 ng/mL) was adopted by the International Federation of Horseracing Authorities (IFHA) in 1996 for controlling testosterone misuse in geldings. In view of the recent popularity of using blood in doping control testing, it is necessary to establish a threshold for testosterone in gelding plasma. A liquid chromatography-mass spectrometry (LC/MS) method was developed for quantifying low levels of free testosterone in gelding plasma. Based on a population study of 152 post-race plasma samples, the mean ± SD concentration of plasma testosterone was determined to be 14.7 ± 6.8 pg/mL. Normal distribution could be obtained after square-root or cube-root transformation, resulting in respective tentative thresholds of 49 or 55 pg/mL (corresponding to a risk factor of less than 1 in 10 000). A rounded-up threshold of 100 pg/mL of free testosterone in plasma was proposed. Based on the administration of Testosterone Suspension 100 to six geldings, the same average detection time of 14 days was observed in either plasma or urine using the proposed plasma threshold and the existing international urine threshold. The maximum detection time was 18 days in plasma and 20 days in urine. The results demonstrated the proposed plasma threshold is effective in controlling the misuse of testosterone in geldings. Similar results were subsequently obtained in Europe, and this proposed threshold was adopted by IFHA in October 2013.

Identification of sample donor by 24-plex short tandem repeat in a post-race equine plasma containing dexamethasone

BackgroundAnimal sport such as horseracing is tainted with drug abuse as are human sports. Treatment of racehorses on race day with therapeutic medications in most cases is banned, and thus, it is essential to monitor the illicit use of drugs in the racing horse to maintain integrity of racing, ensure fair competition and protect the health, safety and welfare of the horse, jockeys and drivers. In the event of a dispute over the identity of the sample donor, if the regulator can provide evidence that the DNA genotype profile of the post-race sample matched that of the alleged donor, then the potential drug violation case might be easily resolved without legal challenges.Case descriptionWe present a case study of a racehorse sample that tested positive for dexamethasone in a post-race plasma sample in Pennsylvania (PA) but the result was challenged by the trainer of the horse. Dexamethasone is a synthetic glucocorticoid widely used in the management of musculoskeletal problems in horses but its presence in the horse during competition is banned by the PA Racing Commissions. The presence of dexamethasone in the post-competition plasma sample was confirmed using liquid chromatography-tandem mass spectrometry. However, this finding was challenged by the trainer of the horse alleging that the post-race sample was not collected from his/her horse and thus petitioned the Commission to be absolved of any wrong-doing. To resolve the dispute, a DNA test was ordered by the PA Racing Commission to identify the correct donor of the dexamethasone positive sample. For this purpose, a 24-plex short tandem repeat analysis to detect 21 equine markers and three human markers was employed. The results indicated that all the samples tested had identical DNA profiles and thus, it was concluded that the samples were collected from the same horse and that the probability of drawing a false conclusion was approximately zero (1.5 × 10-15).ConclusionsThe plasma sample confirmed for the presence of dexamethasone was collected from the alleged horse.

Higher Prevalence of Exercise-Associated Hyponatremia in Triple Iron Ultra-Triathletes Than Reported for Ironman Triathletes

"In a recent study of male and female ultra-marathoners in a 161-km ultra-marathon, the prevalence of exercise-associated hyponatremia (EAH) was higher than reported for marathoners. Regarding triathletes, the prevalence of EAH has been investigated in Ironman triathletes, but not in Triple Iron ultra-triathletes. The aim of this study was to investigate the prevalence of EAH in male ultra-triathletes competing in a Triple Iron ultra-triathlon over 11.4 km swimming, 540 km cycling, and 126.6 km running. Changes in body mass, fat mass, skeletal muscle mass, total body water, haematocrit, plasma volume, plasma sodium concentration ([Na ⁺ ]) and urine specific gravity were determined in 31 male athletes with (means ± standard deviation) 42.1 ± 8.1 years of age, 77.0 ± 7.0 kg body mass, 1.78 ± 0.06 m body height and a BMI of 24.3 ± 1.7 kg/m² in the 'Triple Iron Triathlon Germany'. Of the 31 finishers, eight athletes (26%) developed asymptomatic EAH. Body mass, fat mass, skeletal muscle mass, and haematocrit decreased, plasma volume increased ( P < 0.05), plasma [Na ⁺], total body water and urine specific gravity remained stable. The decrease in body mass was related to both the decrease in fat mass and skeletal muscle mass ( P < 0.05), but was not related to overall race time, the change in plasma [Na ⁺ ], post-race plasma [Na ⁺ ], or urine specific gravity. The prevalence of EAH was higher in these Triple Iron ultra-triathletes compared to existing reports on Ironman triathletes. Body fluid homeostasis remained stable in these ultra-triathletes although body mass decreased."

A faster running speed is associated with a greater body weight loss in 100-km ultra-marathoners

In 219 recreational male runners, we investigated changes in body mass, total body water, haematocrit, plasma sodium concentration ([Na+]), and urine specific gravity as well as fluid intake during a 100-km ultra-marathon. The athletes lost 1.9 kg (s = 1.4) of body mass, equal to 2.5% (s = 1.8) of body mass (P < 0.001), 0.7 kg (s = 1.0) of predicted skeletal muscle mass (P < 0.001), 0.2 kg (s = 1.3) of predicted fat mass (P < 0.05), and 0.9 L (s = 1.6) of predicted total body water (P < 0.001). Haematocrit decreased (P < 0.001), urine specific gravity (P < 0.001), plasma volume (P < 0.05), and plasma [Na+] (P < 0.05) all increased. Change in body mass was related to running speed (r = −0.16, P < 0.05), change in plasma volume was associated with change in plasma [Na+] (r = −0.28, P < 0.0001), and change in body mass was related to both change in plasma [Na+] (r = −0.36) and change in plasma volume (r = 0.31) (P < 0.0001). The athletes consumed 0.65 L (s = 0.27) fluid per hour. Fluid intake was related to both running speed (r = 0.42, P < 0.0001) and change in body mass (r = 0.23, P = 0.0006), but not post-race plasma [Na+] or change in plasma [Na+] (P > 0.05). In conclusion, faster runners lost more body mass, runners lost more body mass when they drank less fluid, and faster runners drank more fluid than slower runners.

An increased fluid intake leads to feet swelling in 100-km ultra-marathoners - an observational field study

BackgroundAn association between fluid intake and changes in volumes of the upper and lower limb has been described in 100-km ultra-marathoners. The purpose of the present study was (i) to investigate the association between fluid intake and a potential development of peripheral oedemas leading to an increase of the feet volume in 100-km ultra-marathoners and (ii) to evaluate a possible association between the changes in plasma sodium concentration ([Na+]) and changes in feet volume.MethodsIn seventy-six 100-km ultra-marathoners, body mass, plasma [Na+], haematocrit and urine specific gravity were determined pre- and post-race. Fluid intake and the changes of volume of the feet were measured where the changes of volume of the feet were estimated using plethysmography.ResultsBody mass decreased by 1.8 kg (2.4%) (p < 0.0001); plasma [Na+] increased by 1.2% (p < 0.0001). Haematocrit decreased (p = 0.0005). The volume of the feet remained unchanged (p > 0.05). Plasma volume and urine specific gravity increased (p < 0.0001). Fluid intake was positively related to the change in the volume of the feet (r = 0.54, p < 0.0001) and negatively to post-race plasma [Na+] (r = -0.28, p = 0.0142). Running speed was negatively related to both fluid intake (r = -0.33, p = 0.0036) and the change in feet volume (r = -0.23, p = 0.0236). The change in the volume of the feet was negatively related to the change in plasma [Na+] (r = -0.26, p = 0.0227). The change in body mass was negatively related to both post-race plasma [Na+] (r = -0.28, p = 0.0129) and running speed (r = -0.34, p = 0.0028).ConclusionsAn increase in feet volume after a 100-km ultra-marathon was due to an increased fluid intake.