Joyce, Kelsey E.

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.

AbstractIntermittent hypoxia has been used to enhance oxygen delivery in athletes and patients; however, it is unclear whether acute exposure is sufficient to elicit lasting physiologic adaptation(s). The purpose of this study was to evaluate physiologic response(s) to hypobaric‐hypoxic (HH) exercise. Nine participants (4 M/5F; 37.9 ± 12.7 yrs.; 174.3 ± 9.4 cm; 75.3 ± 15.9 kg; 24.4 ± 3.4 kg/m2) were exposed to progressively higher simulated altitudes and completed two HH submaximal exercise sessions (~30 min ea., ≥72 h apart) on a cycle ergometer at the first altitude that posed a significant challenge to them. Altitude was dependent on individual response as determined from heart rate (HR), peripheral oxygenation (SpO2), and the ratio of HR response to SpO2 (HR/SpO2). Statistical analyses included paired samples t‐test (p ≤ 0.05). No significant change in SpO2 (HH‐1: 85 ± 4% vs. HH‐2: 85 ± 4%, p = 0.684) was observed between sessions. However, there were significant decreases in: HR (HH‐1: 150 ± 18 bpm vs. HH‐2: 133 ± 27 bpm, p = 0.001) of 18 bpm (11%); HR/SpO2 (HH‐1: 1.76 ± 0.22 vs. HH‐2: 1.57 ± 0.33, p = 0.012); and RPE (HH‐1: 15 ± 2 vs. HH‐2: 11 ± 4, p = 0.017). While workload significantly increased (HH‐1: 89 ± 36 W vs. HH‐2: 105 ± 36 W, p = 0.024). Some participants had a threshold/challenging altitude, but from a single bout there is evidence of improved tolerance that can last over a week. Further investigation is required to replicate and understand possible mechanisms.

Joyce, Kelsey E., Catherine A. Campbell, Arthur R. Bradwell, Samuel J.E. Lucas, Christopher T. Lewis, Rebekah A.I. Lucas, and Mark Edsell; for the Birmingham Medical Research Expeditionary Society (BMRES). The environmental impact of a high-altitude medical research expedition. High Alt Med Biol. 26:140–147, 2025. Introduction: Scientists must begin examining the environmental cost(s) of their research. The purpose of this study was to evaluate a component of the environmental impact of a high-altitude medical research expedition by totaling the carbon dioxide (CO 2 ) emissions calculated from as many direct and indirect sources as possible. Methods: Eighteen individuals flew from London to Bagdogra (via Delhi), and then drove onward to Lachung (via Gangtok) where they began their ascent on foot to 4,800 m (Kanchenjunga National Park, Sikkim). Several research experiments were conducted throughout the expedition, which required use of a laboratory centrifuge, solid CO 2 (specimen storage), rechargeable laptop computers and battery-powered oximeters. International Civil Aviation Organization calculators estimated aviation CO 2 production. Land emissions were calculated for Mahindra vehicles. Solid waste was weighed and CO 2 emissions estimated for its incineration. Results : Total CO 2 emissions equated to ∼16.7 tonnes from the following sources: air and land transportation of expedition team (87.3%); sublimation and transportation of solid CO 2 (7.7%), waste incineration (0.58%), generator transportation and gasoline (12 l) combustion (0.48%), and battery transportation (3.3%). Conclusions : Air travel contributed the most to the overall environmental cost of the research expedition. Further investigation is required to contextualize these findings in relation to lab-based alternative(s).