Chabridon, Loïc

Introduction Ultra-marathon races present a prolonged cardiopulmonary physiological stress but the magnitude, persistence, and impact of race environment on respiratory function are incompletely understood. The aim of this study is to observe the effect of ultra-marathon trail races on both lung function and airway impedance. Methods Fifty-seven individuals (49/8, M/F) participated in either the Courmayeur-Champex-Chamonix (CCC ® , 101.5km), Ultra Trail du Mont-Blanc (UMTB ® , 171.5 km), or the Hong Kong 100 (HK, 100 km) races. Participant demographics were measured pre-race and included: age (40.7±10.3 yrs); height (175.5±7.1 cm), body mass (69.7±8.3 kg). Spirometry, airway impedance (via forced oscillation technique, FOT), maximal inspiratory (MIP) and expiratory pressure (MEP), and exhaled nitric oxide (ExNO) were assessed before, immediately (18–4 hours after), and 188–24 hours post-race. Mixed effects analysis with Dunnett’s post-hoc correction were conducted to evaluate the effects of race and time. Results Results demonstrated significant effects of time for: forced vital capacity (FVC), forced expiratory flow over one second (FEV 1 ), peak expiratory flow (PEF), forced expiratory flow between 25-75% (FEF25-75), forced expiratory flow at 25% and at 50% (FEF 25 and FEF 50 , respectively), MIP, MEP, airway reactance (X) at all frequencies from FOT (X 5 , X 11 , X 19 ), respiratory rate, and ExNO (all p <0.05). A significant effect of race was also observed for ExNO ( p =0.002). Discussion Findings indicate declines in lung function and airway impedance immediately after ultra-marathon races, some of which, persisted up to 24 hours post-race. Further investigations are required to better understand the etiology of changes in lung function following ultra-endurance events.

ABSTRACT 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). Cardiac biomarkers (cTnI and BNP) were assessed from whole blood, whereas lung fluid accumulation (comet tails), stroke volume (SV), and cardiac output ( Q ) were quantified via echocardiography. Lung diffusing capacity for carbon monoxide (DLco) and its components, alveolar membrane conductance (Dm) and capillary blood volume (Vc), were determined via a single-breath method at rest and during three stages of submaximal semirecumbent cycling (20, 30, and 40 W). Results Average race time was 25 ± 12 h. From pre- to post-race, there was an increase in cardiac biomarkers (cTnI: 0.04 ± 0.02 vs 0.13 ± 0.03 ng·mL −1 , BNP: 20 ± 2 vs 112 ± 21 pg·mL −1 ; P < 0.01) and lung comet tails (2 ± 1 vs 7 ± 6, P < 0.01), a decrease in resting and exercise SV (76 ± 2 vs 69 ± 2 mL, 40 W: 93 ± 2 vs 88 ± 2 mL; P < 0.01), and an elevation in Q at rest (4.1 ± 0.1 vs 4.6 ± 0.2 L·min −1 , P < 0.01; 40 W: 7.3 ± 0.2 vs 7.4 ± 0.3 L·min −1 , P = 0.899). Resting DLco and Vc decreased after the race ( P < 0.01), whereas Dm was unchanged ( P = 0.465); however, during the three stages of exercise, DLco, Vc, and Dm were all reduced from pre- to post-race (40 W: 36.3 ± 0.9 vs 33.0 ± 0.8 mL·min −1 ·mm Hg −1 , 83 ± 3 vs 73 ± 2 mL, 186 ± 6 vs 170 ± 7 mL·min −1 ·mm Hg −1 , respectively; P < 0.01). When corrected for alveolar volume and Q , DLco decreased from pre- to post-race ( P < 0.01), and changes in DLco were similar for all ultramarathon events ( P > 0.05). Conclusions Competing in an ultramarathon leads to a transient increase in cardiac injury biomarkers, mild lung-fluid accumulation, and impairments in lung diffusion. Reductions in DLco are predominantly caused by a reduced Vc and possible pulmonary capillary de-recruitment at rest. However, impairments in alveolar–capillary recruitment and Dm both contribute to a fall in exertional DLco following an ultramarathon. Perturbations in lung diffusion were evident across a range of event distances and varying environmental exposures.

Parks, Jordan K, Courtney M. Wheatley-Guy, Glenn M. Stewart, Caitlin C. Fermoyle, Bryan J. Taylor, Jesse Schwartz, Briana Ziegler, Kay Johnson, Alice Gavet, Loïc Chabridon, Paul Robach, and Bruce D. Johnson. Lung “Comet Tails” in healthy individuals: accumulation or clearance of extravascular lung water? High Alt Med Biol. 24:230–233, 2023—Ultrasound lung comet tails (or B-lines) tend to be limited in number (<5) or absent under ultrasound examination, and the appearance of diffuse B-lines with lung sliding has been suggested to identify pulmonary edema. Clinical evaluation of B-lines has been utilized as a bedside test to assess pulmonary congestion in patients with heart failure. Exposure to altitude or prolonged exercise can alter fluid regulation and can lead to pulmonary congestion or edema. As such, B-lines have been utilized in the field to monitor for pathological lung fluid accumulation. However, ultrasound lung comet lines might not be as reliable for identifying extravascular lung water (EVLW) as previously thought in healthy individuals exercising at altitude where an increase in the number of ultrasound lung comets would reflect fluid buildup in the interstitial space of the alveoli and pulmonary capillaries. This report will focus on reviewing the literature and our data from a group of ultraendurance runners that completed the Ultra Trail Mont Blanc race that demonstrates that lung comet tails may not always be evidence of pathological fluid accumulation in healthy individuals and as such should be used to assess EVLW in concert with other diagnostic testing.