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Recently, chronic intermittent inhalation of low-dose carbon monoxide (CO) has been postulated as a practice to increase total hemoglobin mass with potential beneficial effects on endurance performance. In this perspective article, we discuss the potential performance enhancing capabilities as well as the safety concerns, which include individual variability in CO response, and acute and chronic health effects. It is also important to note that according to the World- Anti-Doping-Agency (WADA), CO inhalation could fall under “M1. Manipulation of Blood and Blood Components“ and therefore could be considered a prohibited method if used as a non-diagnostic tool. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the predictive value of parameters of submaximal and maximal cardiopulmonary exercise performance on International Ski Federation (Fédération Internationale de Ski) World Cup ranking (FIS ranking) in elite Austrian Alpine skiers. Methods: Over 7 World Cup seasons (2012–2018), exercise data (maximal oxygen uptake and maximum power output, lactate threshold 2, and ventilatory threshold 2, based on stepwise cycle spiroergometry) were analyzed to determine whether there was a correlation between world FIS ranking and exercise capacity of male and female elite Alpine skiers. Results: The data of 39 male skiers (age: 27.67 [4.20] y, body mass index: 26.03 [1.25] kg/m2) and 36 female skiers (age: 25.49 [3.18] y, body mass index: 22.97 [1.71] kg/m2) were included in this study. The maximum oxygen uptake and maximum power output ranged from 4.37 to 4.42 W/kg and 53.41 to 54.85 mL/kg/min in men and from 4.17 to 4.30 W/kg and 45.96 to 49.16 mL/kg/min in women, respectively, over the 7 seasons; the yearly mean FIS ranking ranged from 17 to 24 in men and 9 to 18 in women. In a fixed-effects model used for the subsequent panel regression analysis, no statistically significant effect on FIS ranking was found for the exercise parameters of interest. Conclusions: Neither maximal aerobic tests nor maximum power output significantly predicted competitive performance, as indexed by the FIS ranking. This reinforces the assumption that no single parameter determines competition performance in this complex sport. Therefore, identifying the optimum amount of endurance training remains a major challenge for athletes and coaches, as does identifying and improving the factors that determine performance. [ABSTRACT FROM AUTHOR]

Background: The altering effects of hypoxia on aerobic/anaerobic performance are well documented and form the basis of this study. Application of hyperoxic gases (inspiratory fraction of oxygen [FiO2] > 0.2095) prior to competition or training (hyperoxic preconditioning) can compensate for the negative influence of acute hypoxia. Purpose: To investigate whether oxygen supplementation immediately prior to exercise (FiO2 = 1.0) improves all-out exercise performance in normobaric hypoxia (3500 m) in highly skilled skiers. Methods: In this single-blind, randomized, crossover study, 17 subjects performed a 60-second constant-load, all-out test in a normobaric hypoxic chamber. After a short period of adaptation to hypoxia (60 min), they received either pure oxygen or chamber air for 5 minutes prior to the all-out test (hyperoxic preconditioning vs nonhyperoxic preconditioning). Capillary blood was collected 3 times, and muscle oxygenation was assessed with near-infrared spectroscopy. Results: Absolute and relative peak power (P =.073 vs P =.103) as well as mean power (P =.330 vs P =.569) did not significantly differ after the hyperoxic preconditioning phase. PaO2 increased from 51.3 (3) to 451.9 (89.0) mm Hg, and SaO2 increased from 88.2% (1.7%) to 100% (0.2%) and dropped to 83.8% (4.2%) after the all-out test. Deoxygenation (P =.700) and reoxygenation rates (P =.185) did not significantly differ for both preconditioned settings. Conclusions: Therefore, the authors conclude that hyperoxic preconditioning did not enhance 60-second all-out exercise performance in acute hypoxia (3500 m). [ABSTRACT FROM AUTHOR]

It is well known that acute hypoxia has negative effects on balance performance. An attempt to compensate for the influence of hypoxia on competition performance was made by the application of hyperoxic gases (inspiratory fraction of oxygen > 0.2095) prior to exercise. Purpose: To investigate whether hyperoxic preconditioning (pure-oxygen supplementation prior to exercise) improves balance ability and postural stability during normobaric hypoxia (3500 m) in highly skilled skiers. Methods: In this single-blind randomized, crossover study, 19 subjects perlormed a 60-s balance test (MFT S3-Check) in a normobaric hypoxic chamber. After a short period of adaptation to hypoxia (60 min), they received either pure oxygen or chamber air for 5 min prior to a balance test (hyperoxic preconditioning vs nonhyperoxic preconditioning). Capillary blood was collected 3 times. Results: Balance performance, indexed by sensory (P = .097), stability (P = .937), and symmetry (P = .202) scores, was not significantly different after the hyperoxic preconditioning phase. Balance performance decreased over time (no group difference). After hyperoxic preconditioning, arterial partial pressure of oxygen increased from 52.7 (4.5) mm Hg to 212.5 (75.8) mm Hg, and oxygen saturation of hemoglobin increased from 85.8% (3.5%) to 98.9% (0.7%) and remained significantly elevated to 90.1% (2.0%) after the balance test. Conclusion: A hyperoxic preconditioning phase does not affect balance performance under hypoxic environmental conditions. A performance-enhancing effect, at least in terms of coordinative functions, was not supported by this study. [ABSTRACT FROM AUTHOR]

Acute infectious diseases of the respiratory tract are regularly associated with increased concentrations of neopterin in serum and/or urine. Most likely, the pteridine compound is not only a marker of an activated cellular immune system but may exert distinct biochemical functions in the process of infections as well. In response to viral contact, macrophages located in the nasal mucosa may represent a source for neopterin in the nasal cavity with potential hazardous effects on ciliary beat frequency (CBF), thus promoting chronic infectious processes. The aim of the present study was to investigate the effects of neopterin at different concentrations (10 nM, 100 nM, and 100 μM) on CBF in human nasal epithelial cells in vitro. Samples were taken from the inferior nasal turbinate and incubated with neopterin dissolved in either aqua destillata or in sodium chloride (0.9%) at the given amounts for 2, 5, 10, and 20 min. In a preliminary set of experiments, neopterin inhibited CBF following the 5 and 10 min. incubation protocol, respectively. However, analyses of pooled data from 28 experiments using sodium chloride (0.9%) as solvent could not confirm these findings: in no setting a significant reduction of CBF was detected at the end of the 20 min. experimental procedure. Therefore, we conclude that neopterin most likely does not affect the mucociliary clearance defense mechanisms in the course of infections of the nasal respiratory tract.

Regular night shift activities are associated with a series of adverse effects (e.g. chronic fatigue, increased yield loss rates, diseases) related to a disturbed circadian rhythm of the employee. According to current knowledge, the human circadian system is affected by visible light in the short wavelength range. In the present study, we investigated the effects of reduced short-wavelength components in the lighting environment of an office workplace on circadian markers, symptoms of lassitude, and personal mood in an experimental night shift setup. Nocturnal urinary neopterin excretion was different from known circadian rhythms under both filtered test light and bright light conditions. By contrast, urinary sulphatoxymelatonin concentrations could be adjusted to a normal diurnal profile in the test light environment. Mood rating inventories did not result in differences in the subjective perception between the two lighting environments with respect to the dimensions of "Activity", "Concentration, "Deactivation", and "Fatigue". In addition, changes in signs of vigour and weariness in the course of each night of the study were equally pronounced in test light and bright light. In conclusion, the present study shows that light with reduced short-wavelength components maintains the nocturnal profile of sulphatoxymelatonin but simultaneously exerts a wearisome effect on the participants. Therefore, a general implementation of test light to illuminate night shift workplaces implies further investigations.