Progressive and biphasic cardiac responses during extreme mountain ultramarathon

Revealing the true nature of a parachute mitral valve during an ultra-trail race

Pre-participation screening and management of congenital cardiac valvulopathy in competitive athletes can be challenging, particularly within the context of ultra-endurance disciplines. A 55-year-old female athlete without a reported history of cardiac disease exhibited clinical signs of cardiogenic pulmonary edema during a 156 km ultra-trail race. The echocardiographic assessment revealed the presence of a parachute mitral valve, with no evidence of mitral stenosis or regurgitation at rest, but it demonstrated severe dynamic mitral stenosis during exercise. In competitive athletes, the detection of rare valvulopathy should prompt a comprehensive cardiac evaluation aimed at assessing the potential for dynamic valvular dysfunction.

The Acute Impact of Endurance Exercise on Right Ventricular Structure and Function: A Systematic Review and Meta-analysis

There have been many studies since the late 1980s investigating the effect of endurance exercise on the left ventricle. More recently, attention has shifted to the right heart, with suggestions that endurance exercise may have a detrimental effect on the right ventricle. This systematic review and meta-analysis summarizes and critiques 26 studies, including 649 athletes, examining the acute impact of endurance exercise on the right ventricle. We also present a subanalysis contrasting ultraendurance with endurance exercise. Finally, we identify areas for future research, such as the influence of sex, ethnicity, and age.

Reduced myocardial strain of interventricular septum among male amateur marathon runners: a cardiac magnetic resonance study

OBJECTIVES

To analyze the long-term effect of multiple marathons on cardiac structure and function in amateur marathon runners compared with healthy controls.

DESIGN

Cross-sectional study using male amateur marathon runners (n = 32) and age-matched cohort of male healthy controls (n = 12).

METHODS

A total of 32 male amateur marathon runners (age 44 ± 7 years) and 12 male healthy controls (age 42 ± 8 years) underwent cardiac magnetic resonance (CMR). The relevant parameters of cardiac structure and function were studied employing feature-tracking strain analysis.

RESULTS

Amateur marathon runners showed lower heart rates, body mass index and body surface area. The left ventricular (LV) mass index, LV end-diastolic volume index and right ventricular end-systolic volume index were significantly higher in amateur marathon runners compared with healthy controls. Furthermore, walls of interventricular septum (IVS) in amateur marathon runners were thicker than healthy controls. There was no significant difference between two groups in the global myocardial strain (MS) in LV. However, the segmental radial and circumferential strains of the LV were lower in amateur marathon runners compared to healthy controls, specifically in the 8th and 9th segments. Finally, we also found as the total running intensity increased, so did global longitudinal strain.

CONCLUSIONS

We reported higher wall thickness and lower regional radial and circumferential strain in the IVS region in amateur marathon runners, suggesting that prolonged and high-intensity exercise may cause cardiac remodeling. Further studies are needed to investigate whether this is an adaptive or maladaptive change in amateur marathon runners.

Investigating the roles of exercise intensity and biological sex on postexercise alterations in cardiac function

The term exercise-induced cardiac fatigue (EICF) has typically been used to describe a transient reduction in cardiac function following prolonged-strenuous exercise. Recent evidence demonstrates that EICF can occur following only 45 min of high-intensity exercise when assessed using exercising stress echocardiography. This investigation sought to examine whether sprint intervals (SIT; 6 × 30 s Wingate tests), or 90-min moderate-cycling with sprint intervals (MIX; 90 min with 1 × 30 s Wingate test every 15 min) would cause greater EICF than 90 min (CON) or 3 h (LONG) moderate-cycling assessed using stress echocardiography, with a secondary aim to interrogate sex differences in EICF. Seventeen participants (M: 9, F: 8) underwent three cycling sessions with stress-echocardiography performed before-and-after each condition at a target heart rate (HR) of 100 beats·min^-1, with the CON testing occurring at the mid-point of the 3 h LONG condition. For all conditions, measures of left ventricular (LV) systolic [stroke volume, ejection fraction (EF), peak longitudinal strain, isovolumetric contraction time, S') and diastolic (E/A, E', isovolumetric relaxation time, longitudinal strain rate) function were reduced after exercise (all P < 0.05). In the right ventricle (RV), systolic function was reduced (tricuspid annular plane systolic excursion, S', peak longitudinal strain and strain rate) following all conditions, and fractional area change was reduced to the greatest degree following SIT (condition × time, P = 0.01). Females demonstrated lesser impairments in LV EF, and elastance (ESP/ESV) compared with males (P < 0.05). Markers of EICF occurred similarly following all cycling loads, suggesting the functional changes may be due to altered loading conditions and reduced stress-echocardiography workload. However, males experienced greater cardiac alterations in some measures, likely due to greater changes in postexercise loading conditions.NEW & NOTEWORTHY This investigation sought to determine the role of exercise intensity on the magnitude of exercise-induced cardiac fatigue using stress echocardiography to maintain loading conditions, with a secondary purpose of assessing sex differences. Unexpectedly, it was found that all cycling loads elicited the same magnitude of functional alteration, which likely represents a common response to exercise and stress echocardiography, rather than intrinsic cardiac impairment. Males demonstrated greater alterations than females, likely due to sex differences in postexercise hemodynamics.

Could Repeated Cardio-Renal Injury Trigger Late Cardiovascular Sequelae in Extreme Endurance Athletes?

Regular exercise confers multifaceted and well-established health benefits. Yet, transient and asymptomatic increases in markers of cardio-renal injury are commonly observed in ultra-endurance athletes during and after competition. This has raised concerns that chronic recurring insults could cause long-term cardiac and/or renal damage. Indeed, extreme endurance exercise (EEE) over decades has sometimes been linked with untoward cardiac effects, but a causal relation with acute injury markers has not yet been established. Here, we summarize the current knowledge on markers of cardiac and/or renal injury in EEE athletes, outline the possible interplay between cardiac and kidney damage, and explore the roles of various factors in the development of potential exercise-related cardiac damage, including underlying diseases, medication, sex, training, competition, regeneration, mitochondrial dysfunction, oxidative stress, and inflammation. In conclusion, despite the undisputed health benefits of regular exercise, we speculate, based on the intimate link between heart and kidney diseases, that in rare cases excessive endurance sport may induce adverse cardio-renal interactions that under specific, hitherto undefined conditions could result in persistent cardiac damage. We highlight future research priorities and provide decision support for athletes and clinical consultants who are seeking safe strategies for participation in EEE training and competition.

A long duration race induces a decrease of left ventricular strains, twisting mechanics and myocardial work in trained adolescents

BACKGROUND

We investigated the acute cardiac consequences of a long-duration (>5 h) adventure race in adolescent athletes from evaluations of left ventricular (LV) strains and myocardial work.

METHODS

Twenty trained male adolescents (i.e. 8 ± 4 hours/week of endurance sports) aged 14 to 17 years participated in a competitive long-duration adventure race. Blood samples were collected before, immediately and 24 h after the race to determine the time course of troponin I (cTnI) considered as a myocardial damage biomarker. Resting echocardiography were conducted before and after the race to assess myocardial regional strains, LV twisting mechanics and myocardial work using speckle tracking echocardiography.

RESULTS

The mean completion time of the race was 05:38 ± 00:20 h, with a mean heart rate (HR) of 83 ± 5% of maximal HR. cTnI concentration significantly increased in 16/20 participants after the race (pre: 0.001 ± 0.002 vs. post: 0.244 ± 0.203 ng·dL^-1, p < 0.001) and returned to baseline within 24 h. Stroke volume, ejection fraction and global longitudinal strains remained unchanged after the race while LV twist and global myocardial work significantly decreased (8.6 ± 3.3 vs. 6.3 ± 3.3 deg and 2080 ± 250 vs. 1781 ± 334 mmHg%, p < 0.05). Diastolic function, indexes of myocardial relaxation and LV untwisting rate (-91.0 ± 19.0 vs. -56.4 ± 29.1 deg·s^-1, p < 0.001) were affected after the race.

CONCLUSION

We demonstrated for the first time that, in trained adolescents, a high-intensity endurance exercise of several hours induced an increase of the cTnI concentration associated with an alteration of myocardial function.

Kinetics of Cardiac Remodeling and Fibrosis Biomarkers During an Extreme Mountain Ultramarathon

Objectives

The effects of ultra-distance on cardiac remodeling and fibrosis are unclear. Moreover, there are no data reporting the kinetics of cardiac alterations throughout the event and during recovery. Our aim was to investigate the kinetics of biological markers including new cardiac fibrosis biomarkers suppression of tumorigenicity 2 (ST2) and galectin-3 (Gal-3) during and after an extreme mountain ultramarathon.

Methods

Fifty experienced runners participating in one of the most challenging mountain ultramarathons (330 km, D+ 25,000 m) were enrolled in our study. Blood samples were collected at four time points: before (Pre-), at 148 km (Mid-), at the finish line (Post-), and 3 days after the recovery period (Recov-).

Results

The cardiac fibrosis biomarkers (ST2 and Gal-3) increased from Pre- to Mid-. During the second half, ST2 remained higher than pre-values as opposed to Gal-3. Necrosis, ischemia, and myocyte injury biomarkers increased until Mid- then decreased but remained higher at Recov- than Pre-values. Oxidative stress appeared at Mid-. Lipid peroxides remained higher at Recov- compared to Pre-. The maximal value in most of these biomarkers was observed at Mid- and not at Post-.

Conclusions

The present study supports biphasic kinetics of cardiac fibrosis biomarkers, with a relative recovery during the second half of the event that seems specific to this extreme event. Overall, performing at such an extreme ultramarathon seems less deleterious for the heart than shorter events.

Pulmonary and Inspiratory Muscle Function Response to a Mountain Ultramarathon

The study aimed to provide within-race data on the time course of pulmonary function during a mountain ultramarathon (MUM). Additionally, we wanted to assess possible sex differences regarding pre- to post-race change in pulmonary and inspiratory muscle function. Lastly, we were interested in evaluating whether changes in respiratory function were associated with relative running speed and due to general or specific fatigue. 47 athletes (29 males and 18 females; 41 ± 5 years) were submitted to a cardiopulmonary exercise test (CPET) before a 107-km MUM. Spirometric variables: forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV₁/FVC and peak expiratory flow (PEF); maximal inspiratory pressure (MIP); squat jump (SJ) and handgrip strength (HG) were assessed before and after the race. Additionally PEF was measured at three aid stations (33^rd, 66^th and 84^th km) during the race. PEF declined from the 33^rd to the 66^th km (p = 0.004; d = 0.72) and from the 84^th km to the finish line (p = 0.003; d = 0.90), while relative running speed dropped from the first (0-33 km) to the second (33-66 km) race section (p < 0.001; d = 1.81) and from the third (66-84 km) to the last race section (p < 0.001; d = 1.61). Post-race, a moderate reduction was noted in FVC (-13%; p < 0.001; d = 0.52), FEV₁ (-19.5%; p < 0.001; d = 0.65), FEV₁/FVC (-8.4%; p = 0.030; d = 0.59), PEF (-20.3%; p < 0.001; d = 0.58), MIP (-25.3%; p < 0.001; d = 0.79) and SJ (-31.6%; p < 0.001; d = 1.42). Conversely, HG did not change from pre- to post-race (-1.4%; p = 0.56; d = 0.05). PEF declined during the race in parallel with running speed drop. No sex differences were noted regarding post-race respiratory function, except that FEV₁/FVC decay was significantly greater among women. The magnitude of pre- to post-race respiratory function decline was uncorrelated with relative running speed.

Impact of a 246 Km ultra-marathon running race on heart: Insights from advanced deformation analysis

Although previous studies suggest that prolonged intense exercise such as marathon running transitorily alters cardiac function, there is little information regarding ultramarathon races. Aim of this study was to investigate the acute impact of ultra-endurance exercise (UEE) on heart, applying advanced strain imaging. Echocardiographic assessment was performed the day before and at the finish line of "Spartathlon": A 246 Km ultra-marathon running race. 2D speckle-tracking echocardiography was performed in all four chambers, evaluating longitudinal strain (LS) for both ventricles and atria. Peak strain values and temporal parameters adjusted for heart rate were extracted from the derived curves. Out of 60 participants initially screened, 27 athletes (19 male, age 45 ± 7 years) finished the race in 33:34:27(28:50:38-35:07:07) hours. Absolute values of right (RV) and left ventricular (LV) LS (RVLS -22.9 ± 3.6 pre- to -21.2 ± 3.0% post-, p=0.04 and LVLS -20.9 ± 2.3 pre- to -18.8 ± 2.0 post-, p=0.009) slightly decreased post-race, whereas atrial strain did not change. RV and LV LS decrease was caused mainly by strain impairment of basal regions with apical preservation. Inter-chamber relationships assessed through RV/LV, LV/LA, RV/RA and RA/LA peak values' ratios remained unchanged from pre to post-race. Finally, UEE caused an extension of the systolic phase of cardiac cycle with concomitant diastole reduction (p<0.001 for all strain curves). Conclusively, ventricular LS strain as well as effective diastolic period slightly decreased, whereas atrial strain and inter-chamber relationships remained unchanged after running a 246-km-ultra-marathon race. These changes may be attributed to concomitant pre- and afterload alterations following UEE.

Quantitative Magnetic Resonance Imaging Assessment of the Quadriceps Changes during an Extreme Mountain Ultramarathon

INTRODUCTION/PURPOSE

Extreme ultra-endurance races are growing in popularity, but their effects on skeletal muscles remain mostly unexplored. This longitudinal study explores physiological changes in mountain ultramarathon athletes' quadriceps using quantitative magnetic resonance imaging (MRI) coupled with serological biomarkers. The study aimed to monitor the longitudinal effect of the race and recovery and to identify local inflammatory and metabolic muscle responses by codetection of biological markers.

METHODS

An automatic image processing framework was designed to extract imaging-based biomarkers from quantitative MRI acquisitions of the upper legs of 20 finishers at three time points. The longitudinal effect of the race was demonstrated by analyzing the image markers with dedicated biostatistical analysis.

RESULTS

Our framework allows for a reliable calculation of statistical data not only inside the whole quadriceps volume but also within each individual muscle head. Local changes in MRI parameters extracted from quantitative maps were described and found to be significantly correlated with principal serological biomarkers of interest. A decrease in the PDFF after the race and a stable paramagnetic susceptibility value were found. Pairwise post hoc tests suggested that the recovery process differs among the muscle heads.

CONCLUSIONS

This longitudinal study conducted during a prolonged and extreme mechanical stress showed that quantitative MRI-based markers of inflammation and metabolic response can detect local changes related to the prolonged exercise, with differentiated involvement of each head of the quadriceps muscle as expected in such eccentric load. Consistent and efficient extraction of the local biomarkers enables to highlight the interplay/interactions between blood and MRI biomarkers. This work indeed proposes an automatized analytic framework to tackle the time-consuming and mentally exhausting segmentation task of muscle heads in large multi-time-point cohorts.

Recommendations on Youth Participation in Ultra-Endurance Running Events: A Consensus Statement

Participation in ultra-endurance running (UER) events continues to grow across ages, including youth athletes. The 50- and 100-km are the most popular distances among youth athletes. Most youth athletes are between 16-18 years; however, some runners younger than 12 years have successfully completed UER events. Parents, athletes, coaches, race directors, and medical professionals often seek advice regarding the safety of youth athletes participating in these events, especially with regard to potential short and long-term health consequences. UER may impact key organ systems during growth and development. We propose a decision-making process, based on current knowledge and the experience of the consensus group that addresses age regulations, medical and psychological well-being, training status and race-specific factors (such as distance, elevation change, remoteness, ambient temperatures, level of medical assistance, and type of provisions provided by the race organizers) to use until evidence of long-term consequences of UER in youth athletes is available. These recommendations are aimed at safe participation in UER events for youth athletes with a proper and individualized assessment.

Electrical Cardiometry and Cardiac Biomarkers in 24-h and 48-h Ultramarathoners

Our study aimed to (i) utilize novel electrical cardiometry and observe acute changes in cardiac biomarkers among 24-h and 48-h ultra-marathoners, and (ii) examine whether alterations in cardiac responses were associated with the average running speed of these participants. Twenty-four 24-h and sixteen 48-h ultra-marathoners were recruited. Electrical cardiometry in the 2 groups showed significant post-race drops in systolic pressure (24-h: p=0.001; 48-h: p=0.016) and rapid increases in heart rate (24-h, p=0.004; 48-h, p=0.001). Cardiac output increased in 48-h runners (p=0.012) and stroke volume decreased in 24-h runners (p=0.009) at post-test. Six of 20 (30%) 24-h and 4 of 16 (25%) 48-h runners had high-sensitivity troponin T values above the reference interval after the races. N-terminal proB-type natriuretic peptide levels showed a 15-fold increase in 24-h runners and a 10-fold increase in 48-h runners at post-race. There was a positive correlation between delta N-terminal proB-type natriuretic peptide and running mileage (rs=0.629, p=0.003) in 24-h ultra-marathoners. In conclusion, stroke volume and cardiac output showed inconsistent changes between the 2 groups. Average running speed has a significant effect on post-exercise elevation in cardiac biomarkers.

Exploring the determinants of the cardiac changes after ultra-long duration exercise: The echocardiographic Spartathlon study

Aim

The investigation of the pathophysiological determinants of cardiac changes following ultra-long duration exercise.

Methods

Twenty-seven runners who finished a 246 km running race were examined both before and after the finish of the race. Examinations included echocardiography and measurement of body weight and blood biochemical parameters.

Results

Exercise increased left ventricular end-diastolic interventricular septum thickness (LVIVSd) ( p < 0.001) and posterior wall thickness (LVPWTd) ( p = 0.001) and right ventricular end-diastolic area ( p = 0.005), while reduced tricuspid annular plane systolic excursion (TAPSE) ( p = 0.004). A minor decrease in the peak absolute values of both left ventricular (from −20.9 ± 2.3% to −18.8 ± 2.0%, p = 0.009) and right ventricular (from −22.9 ± 3.6% to −21.2 ± 3.0%, p = 0.040) global longitudinal strains occurred. There was decrease in body weight ( p < 0.001) and increase in both circulating high-sensitivity troponin I ( p = 0.028) and amino-terminal pro-B type natriuretic peptide (NT-proBNP) ( p = 0.018). The change in the sum of LVIVSd and LVPWTd correlated negatively with percentage change of body weight ( r = −0.416, p = 0.049). The only independent determinant of post-exercise NT-proBNP was pulmonary artery systolic pressure ( r = 0.797, p = 0.002). Post-exercise NT-proBNP correlated positively with percentage changes of basal (RVbas) ( r = 0.582, p = 0.037) and mid-cavity (RVmid) ( r = 0.618, p = 0.043) right ventricular diameters and negatively with percentage change of TAPSE ( r = −0.720, p = 0.008). Similar correlations with RVbas, RVmid and TAPSE were found for pulmonary artery systolic pressure. Post-exercise high-sensitivity troponin I correlated negatively with percentage change of body weight ( r = −0.601, p = 0.039), but was not associated with any cardiac parameter.

Conclusion

The main cardiac effects of ultra-long duration exercise were the decrease in left ventricular end-diastolic dimensions and increase in left ventricular wall thickness, as well as minimal dilatation and alteration in systolic function of right ventricle, possibly due to the altered exercise-related right ventricular afterload.

Cardiac structure and function in response to a multi-stage marathon over 4486 km

Aims

To investigate whether participation in the Trans Europe Foot Race 2009 (TEFR), an ultramarathon race held over 64 consecutive days and 4486 km, led to changes in cardiac structure and function.

Methods

Cardiac magnetic resonance imaging was performed in 20 of 67 participating runners (two women; mean ± SD age 47.8 ± 10.4 years) at three time points (baseline scan at 294 ± 135 km (B), scan two at 1735 ± 86 km (T1) and scan three at 3370 ± 90 km (T2)) during the TEFR. Imaging included an assessment of left ventricular structure (mass) and function (strain). In parallel, cardiac troponin I, NT-pro-BNP, myostatin and GDF11 were determined in venous blood samples. A subsample of ten runners returned for a follow-up scan eight months after the race.

Results

Left ventricular mass increased significantly (B, 158.5 ± 23.8 g; T1, 165.1 ± 23.2 g; T2, 167 ± 24.6 g; p &lt; 0.001) over the course of the race, although no significant change was seen in the remaining structural and functional parameters. Serum concentrations of cardiac troponin I and NT-proBNP significantly increased 1.5 - and 3.5-fold, respectively, during the first measurement interval, with no further increase thereafter (cardiac troponin I, 6.8 ± 3.1 (B), 16.9 ± 10.4 (T1) and 17.1 ± 9.7 (T2); NT-proBNP, 30.3 ± 22.8 (B), 135.9 ± 177.5 (T1) and 111.2 ± 87.3 (T2)), whereas the growth markers myostatin and GDF11 did not change. No association was observed with functional parameters, including the ejection fraction and the volume of both ventricles. The follow-up scans showed a reduction to baseline values (left ventricular mass 157 ± 19.3 g).

Conclusions

High exercise-induced cardiac volume load for &gt;2 months in ultra-endurance runners results in a physiological structural adaptation with no sign of adverse cardiovascular remodelling.

Postural Control Follows a Bi-Phasic Alteration Pattern During Mountain Ultra-Marathon

It is well knows that postural control (PC) is deteriorated with neuromuscular fatigue, altitude or sleep deprivation induced by a mountain ultra-marathon (MUM). Several regulatory mechanisms have also been reported during this type of event and the changes in PC at different points of MUM remain unknown. The purpose of this study was to investigate the time course of PC during an extreme MUM. We tested the hypothesis that PC alteration would not increase linearly.

Methods: 16 participants (age 45.1 ± 9.6 years) were tested bipedaly on a posturographic platform for 51.2 s with eyes open every ∼50 km. Both traditional and stabilogram diffusion analyses (SDA) were performed. A visual analog scale (VAS) was used for a subjective evaluation of global fatigue, sleep feeling and pain.

Results: The main parameters (center of pressure trajectory analysis) increased significantly (p < 0.001, d = 1.56, very large) until km 100. This was confirmed by SDA in the antero-posterior plane. Short term effective diffusion coefficient significantly increased (p < 0.001, d = 1.07, very large) as critical point (p < 0.01, d = 1.57, very large). From km 100 to 200, a different response was observed with a continuous decrease in most of the PC parameters. This was confirmed by SDA in the antero-posterior plane. Short term effective diffusion coefficient significantly increased (p < 0.001, d = 1.39, very large) as critical point (p < 0.01, d = 1.51, very large).

Conclusion: Posture alteration is progressively increased until 100 km. After this point, compensatory mechanisms appear to limit the posture degradation. This bi-phasic response is of interest for better understanding the coping with extreme fatigue.

Cognitive performance and self-reported sleepiness are modulated by time-of-day during a mountain ultramarathon

Ninety-two runners completed the study during a 168 km mountain ultramarathon (MUM). Sleepiness, self-reported sleep duration, and cognitive performance were assessed the day before the race and up to eight checkpoints during the race. Sleepiness was assessed using the Karolinska Sleepiness Scale. Cognitive performance was also assessed using the Digital Symbol Substitution Task (DSST). Runner reported 23.40 ± 22.20 minutes of sleep (mean ± SD) during the race (race time: 29.38 to 46.20 hours). Sleepiness and cognitive performance decrements increased across this race, and this was modulated by time-of-day with higher sleepiness and greater performance decrements occurring during the early morning hours. Runners who slept on the course prior to testing had poorer cognitive performance, which may suggest that naps on the course were taken due to extreme exertion. This study provides evidence that cognitive performance deficits and sleepiness in MUM are sensitive to time into race and time-of-day.

Physiology and Pathophysiology in Ultra-Marathon Running

In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time) is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer ultra-marathons, ~50–60% of the participants experience musculoskeletal problems. The most common injuries in ultra-marathoners involve the lower limb, such as the ankle and the knee. An ultra-marathon can lead to an increase in creatine-kinase to values of 100,000–200,000 U/l depending upon the fitness level of the athlete and the length of the race. Furthermore, an ultra-marathon can lead to changes in the heart as shown by changes in cardiac biomarkers, electro- and echocardiography. Ultra-marathoners often suffer from digestive problems and gastrointestinal bleeding after an ultra-marathon is not uncommon. Liver enzymes can also considerably increase during an ultra-marathon. An ultra-marathon often leads to a temporary reduction in renal function. Ultra-marathoners often suffer from upper respiratory infections after an ultra-marathon. Considering the increased number of participants in ultra-marathons, the findings of the present review would have practical applications for a large number of sports scientists and sports medicine practitioners working in this field.

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Zusammenfassung. Wir stellen die wichtigsten Erkenntnisse zu Organschädigungen durch einen Ultramarathon zusammen. Nach einem Ultramarathon können kardiale Biomarker wie CK, CK-MB, kardiales Troponin I (cTnI) und N-terminales pro-Brain Natriuretic Peptide (NT-pro BNP) erhöht sein. Bis 80 % und mehr der Finisher klagen über Verdauungsprobleme, die einer der Hauptgründe sind, einen Ultramarathon nicht zu finishen. Bis zu 90 % der Läufer, die einen Ultramarathon aufgeben, klagen über Übelkeit. Nach einem Ultramarathon steigen die Leberwerte oft an, schwerwiegende Konsequenzen bleiben meist aus. Risikofaktoren für eine Einschränkung der Nierenfunktion sind eine ausgeprägte Muskelschädigung mit Rhabdomyolyse, Dehydratation, Hypotonie, Hyperurikämie, Hyponatriämie, geringe Wettkampferfahrung sowie die Einnahme von NSARs. Ultraläufer leiden nach einem Ultramarathon oft an Infekten der oberen Atemwege.

Extreme Mountain Ultra-Marathon Leads to Acute but Transient Increase in Cerebral Water Diffusivity and Plasma Biomarkers Levels Changes

Background: Pioneer studies demonstrate the impact of extreme sport load on the human brain, leading to threatening conditions for athlete's health such as cerebral edema. The investigation of brain water diffusivity, allowing the measurement of the intercellular water and the assessment of cerebral edema, can give a great contribution to the investigation of the effects of extreme sports on the brain. We therefore assessed the effect of supra-physiological effort (extreme distance and elevation changes) in mountain ultra-marathons (MUMs) athletes combining for the first time brain magnetic resonance imaging (MRI) and blood parameters.

Methods:This longitudinal study included 19 volunteers (44.2 ± 9.5 years) finishing a MUM (330 km, elevation + 24000 m). Quantitative measurements of brain diffusion-weighted images (DWI) were performed at 3 time-points: Before the race, upon arrival and after 48 h. Multiple blood biomarkers were simultaneously investigated. Data analyses included brain apparent diffusion coefficient (ADC) and physiological data comparisons between three time-points.

Results:The whole brain ADC significantly increased from baseline to arrival (p = 0.005) and then significantly decreased at recovery (p = 0.005) to lower values than at baseline (p = 0.005). While sodium, potassium, calcium, and chloride as well as hematocrit (HCT) changed over time, the serum osmolality remained constant. Significant correlations were found between whole brain ADC changes and osmolality (p = 0.01), cholesterol (p = 0.009), c-reactive protein (p = 0.04), sodium (p = 0.01), and chloride (p = 0.002) plasma level variations.

Conclusions:These results suggest the relative increase of the inter-cellular volume upon arrival, and subsequently its reduction to lower values than at baseline, indicating that even after 48 h the brain has not fully recovered to its equilibrium state. Even though serum electrolytes may only indirectly indicate modifications at the brain level due to the blood brain barrier, the results concerning osmolality suggest that body water might directly influence the change in cerebral ADC. These findings establish therefore a direct link between general brain inter-cellular water content and physiological biomarkers modifications produced by extreme sport.

Shear-Wave Elastography Assessments of Quadriceps Stiffness Changes prior to, during and after Prolonged Exercise: A Longitudinal Study during an Extreme Mountain Ultra-Marathon

In sports medicine, there is increasing interest in quantifying the elastic properties of skeletal muscle, especially during extreme muscular stimulation, to improve our understanding of the impact of alterations in skeletal muscle stiffness on resulting pain or injuries, as well as the mechanisms underlying the relationships between these parameters. Our main objective was to determine whether real-time shear-wave elastography (SWE) can monitor changes in quadriceps muscle elasticity during an extreme mountain ultra-marathon, a powerful mechanical stress model. Our study involved 50 volunteers participating in an extreme mountain marathon (distance: 330 km, elevation: +24,000 m). Quantitative SWE velocity and shear modulus measurements were performed in most superficial quadriceps muscle heads at the following 4 time points: before the race, halfway through the race, upon finishing the race and after recovery (+48 h). Blood biomarker levels were also measured. A significant decrease in the quadriceps shear modulus was observed upon finishing the race (3.31±0.61 kPa) (p<0.001) compared to baseline (3.56±0.63 kPa), followed by a partial recovery +48 h after the race (3.45±0.6 kPa) (p = 0.002) across all muscle heads, as well as for each of the following three muscle heads: the rectus femoris (p = 0.003), the vastus medialis (p = 0.033) and the vastus lateralis (p = 0.001). Our study is the first to assess changes in muscle stiffness during prolonged extreme physical endurance exercises based on shear modulus measurements using non-invasive SWE. We concluded that decreases in stiffness, which may have resulted from quadriceps overuse in the setting of supra-physiological stress caused by the extreme distance and unique elevation of the race, may have been responsible for the development of inflammation and muscle swelling. SWE may hence represent a promising tool for monitoring physiologic or pathological variations in muscle stiffness and may be useful for diagnosing and monitoring muscle changes.