Publications by authors named "Robach P"

Stauffer, Emeric, François Caton, Raphael Marlu, Aurélien Pichon, Landry Seyve, Michael Furian, Aymeric Paillisser, Florence Berquet, Jeremy De Abreu, Blandine Deschamps, Benoit Polack, Philippe Connes, Paul Robach, Stéphane Doutreleau, Julien V Brugniaux, Samuel Verges, and Benoit Champigneulle.Acclimatized lowlanders exhibit a hypocoagulable profile after a passive ascent at high altitude. 00:00-00, 2024.

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Purpose: To investigate the effects of a repeated-sprint training in hypoxia induced by voluntary hypoventilation at low lung volume (RSH-VHL) including end-expiratory breath holding (EEBH) of maximal duration.

Methods: Over a 4-week period, twenty elite judo athletes (10 women and 10 men) were randomly split into two groups to perform 8 sessions of rowing repeated-sprint exercise either with RSH-VHL (each sprint with maximal EEBH) or with unrestricted breathing (RSN, 10-s sprints). Before (Pre-), 5 days after (Post-1) and 12 days after (Post-2) the last training session, participants completed a repeated-sprint ability (RSA) test on a rowing ergometer (8 × 25-s "all-out" repetitions interspersed with 25 s of passive recovery).

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Background: Since vascular responses to hypoxia in both healthy high-altitude natives and chronic mountain sickness (a maladaptive high-altitude pathology characterised by excessive erythrocytosis and the presence of symptoms-CMS) remain unclear, the role of inflammation and oxidative/nitrosative stress on the endothelium- and - responses in both the micro- and macrocirculation, in healthy Andeans at different altitudes and in CMS patients, was examined.

Methods: 94 men were included: 18 lowlanders (LL), 38 healthy highlanders permanently living at 3800 m (n = 21-HL-3800) or in La Rinconada, the highest city in the world (5100-5300 m) (n = 17-HL-5100/No CMS). Moreover, 14 participants with mild (Mild CMS) and 24 with moderate to severe CMS (Mod/Sev CMS) were recruited.

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We investigated highlanders, permanently living at an altitude of 5100 m and compared Chronic Mountain Sickness (CMS) patients with control volunteers. While we found differences in systemic parameters such as blood oxygen content, hematocrit, hemoglobin concentration, and blood viscosity, the mechanical and rheological properties of single red blood cells did not differ between the two investigated groups.

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Introduction: Endurance exercise at altitude can increase cardiac output and pulmonary vascular pressure to levels that may exceed the stress tolerability of the alveolar-capillary unit. This study examined the effect of ultramarathon trail racing at different altitudes (ranging from <1000 m to between 1500 and 2700 m) on alveolar-capillary recruitment and lung diffusion.

Methods: Cardiac and lung function were examined before and after an ultramarathon in 67 runners (age: 41 ± 9 yr, body mass index: 23 ± 2 kg·m -2 , 10 females), and following 12-24 h of recovery in a subset ( n = 27).

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Chronic mountain sickness is a maladaptive syndrome that affects individuals living permanently at high altitude and is characterized primarily by excessive erythrocytosis (EE). Recent results concerning the impact of EE in Andean highlanders on clotting and the possible promotion of hypercoagulability, which can lead to thrombosis, were contradictory. We assessed the coagulation profiles of Andeans highlanders with and without excessive erythrocytosis (EE+ and EE-).

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Exhaustive exercise can induce unique physiological responses in the lungs and other parts of the human body. The volatile organic compounds (VOCs) in exhaled breath are ideal for studying the effects of exhaustive exercise on the lungs due to the proximity of the breath matrix to the respiratory tract. As breath VOCs can originate from the bloodstream, changes in abundance should also indicate broader physiological effects of exhaustive exercise on the body.

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Article Synopsis
  • A novel urine sampling method was developed to more accurately measure drug use in ultramarathon runners compared to traditional questionnaires.
  • Out of 412 urine samples tested, nearly half showed the presence of drugs, with 16.3% containing prohibited substances, particularly NSAIDs and painkillers.
  • The study revealed that self-reported drug use via questionnaires was lower than actual findings from urine samples, indicating the effectiveness of blind urine testing in detecting undisclosed drug use among athletes.
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Exposure to chronic hypobaric hypoxia imposes a significant physiological burden to more than 80 million humans living above 2500 m throughout the world. Among them, 50 000 live in the world's highest city, La Rinconada, located at 5000-5300 m in southern Peru. Expedition 5300 is the first scientific and medical programme led in La Rinconada to investigate the physiological adaptations and altitude-related health issues in this unique population.

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Article Synopsis
  • The study examines how blood volume (BV) per kg of body mass (BM) may underestimate BV in individuals with high fat mass, particularly highlighting differences between sexes, ages, and fitness levels.* -
  • It was found that women had a lower BV/BM compared to men by 25%, but when adjusted for lean body mass (LBM), women showed a 6% higher BV/LBM.* -
  • Among athletes, BV/BM was 17.2% higher than non-athletes, but this difference shrank to only 2.5% when adjusted for LBM, indicating that LBM is a strong predictor of BV and hemoglobin mass (Hb) in clinical assessments.*
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Louis, Alexandre, Charlotte Pröpper, Yann Savina, Corentin Tanne, Guy Duperrex, Paul Robach, Pascal Zellner, Stéphane Doutreleau, Jean-Michel Boulet, Alain Frey, Fabien Pillard, Cristina Pistea, Mathias Poussel, Thomas Thuet, Jean-Paul Richalet, and François Lecoq-Jammes. The impact of COVID-19 on the response to hypoxia. .

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Article Synopsis
  • The study examines ultrasound lung comet tails (B-lines), which are typically used to detect pulmonary edema, especially in heart failure patients, and their presence is often thought to indicate fluid accumulation in unhealthy individuals.
  • Researchers found that during extreme physical activities like the Ultra Trail Mont Blanc race, healthy individuals exhibited an increased number of comet tails, prompting questions about the reliability of B-lines as an indicator of extravascular lung water in these circumstances.
  • The authors suggest that B-lines may not always signify pathological conditions in healthy athletes, recommending a multi-faceted approach for assessing fluid levels in the lungs rather than solely relying on ultrasound findings.
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Introduction And Objectives: Chronic Mountain Sickness (CMS) syndrome, combining excessive erythrocytosis and clinical symptoms in highlanders, remains a public health concern in high-altitude areas, especially in the Andes, with limited therapeutic approaches. The objectives of this study were to assess in CMS-highlanders permanently living in La Rinconada (5100-5300 m, Peru, the highest city in the world), the early efficacy of acetazolamide (ACZ) and atorvastatin to reduce hematocrit (Hct), as well as the underlying mechanisms focusing on intravascular volumes.

Materials And Methods: Forty-one males (46±8 years of age) permanently living in La Rinconada for 15 [10-20] years and suffering from CMS were randomized between ACZ (250 mg once-daily; N = 13), atorvastatin (20 mg once-daily; N = 14) or placebo (N = 14) uptake in a double-blinded parallel study.

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Aims: A unique Andean population lives in the highest city of the world (La Rinconada, 5100 m, Peru) and frequently develops a maladaptive syndrome, termed chronic mountain sickness (CMS). Both extreme altitude and CMS are a challenge for the cardiovascular system. This study aims to evaluate cardiac remodelling and pulmonary circulation at rest and during exercise in healthy and CMS highlanders.

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Article Synopsis
  • This study investigates the physiological responses of female ultramarathon runners, comparing them with male counterparts during and after a race.
  • Data were collected from 53 ultramarathon participants, focusing on specific biomarkers and lung function measurements before and after racing.
  • Results show that females had significant increases in certain biomarkers post-race, while males demonstrated greater reductions in lung capacity and evidence of mild pulmonary edema, indicating different physiological impacts between genders.
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Purpose: Both prolonged exercise and acute high-altitude exposure are known to induce cardiac changes. We sought to describe the cardiac responses to speed climbing at high-altitude, including left ventricular (LV) performance assessment using the myocardial work index (MWI), a new index derived from 2D speckle tracking echocardiography (STE).

Methods: Eleven elite alpinists (9 males, age: 26 ± 4 years) were evaluated before and immediately after a speed ascent of the Mont-Blanc (4808 m) by echocardiography using conventional measurements as well as STE and MWI computation with derivate parameters as global work efficiency (GWE) or global wasted work (GWW).

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Purpose: The combined effects of acute hypoxia and exercise on cognition remain to be clarified. We investigated the effect of speed climbing to high altitude on reactivity and inhibitory control in elite climbers.

Methods: Eleven elite climbers performed a speed ascent of the Mont-Blanc (4810 m) and were evaluated pre- (at 1000 m) and immediately post-ascent (at 3835 m).

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Background: Endurance running events are known to cause inflammation and result in increased cytokine production. However, the effects of ultramarathons on cytokine profiles are not well characterized.

Objective: The aim of this study was to describe and compare the effects of a trail (40 km) race and an ultra-trail (171 km) race on leukocyte concentrations and cytokine profiles.

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Blood rheology is a key determinant of tissue perfusion at rest and during exercise. The present study investigated the effects of race distance on hematological, blood rheological, and red blood cell (RBC) senescence parameters. Eleven runners participated in the Martigny-Combes à Chamonix 40 km race (MCC, elevation gain: 2300 m) and 12 others in the Ultra-Trail du Mont Blanc (UTMB, 171 km, elevation gain: 10,000 m).

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