Athletes Do Not Condition Inspired Air More Effectively than Nonathletes during Hyperpnea

Endurance athletes have a high prevalence of airway diseases, some possibly representing adaptive mechanisms to the need of conditioning large volumes of inspired air during high ventilation in specific environments. The aim of this study is to assess the ability to condition (warm and humidify) inspired air in athletes by measuring the difference between inhaled and exhaled air temperature (ΔT) during and after eucapnic voluntary hyperpnea (EVH) test.

Twenty-three endurance athletes from various sports, 12 with airway hyperresponsiveness (AHR) and/or exercise-induced bronchoconstriction (EIB) (A+), 11 without AHR and/or EIB (A-), 12 nonathletes with AHR and/or EIB (C+), and 11 nonathletes without AHR and/or EIB (C-) were recruited. All subjects attended the laboratory on three occasions, twice for baseline characterization, including questionnaires, pulmonary function, methacholine bronchoprovocation, allergy skin prick tests, exhaled nitric oxide measurement, and a standard EVH, and once to perform a modified EVH to assess ΔT. Inspired and expired air temperatures were measured with a high-precision probe during EVH and at regular intervals until 30 min after the end of the test.

The global ΔT during the EVH was +5.8°C ± 1.5°C and +4.7°C ± 1.5°C during the 30 min after the EVH. No difference was found between groups for either the ΔT or the slope of ΔT, during and after the EVH.

This study shows no evidence of improved capacity to condition inspired air in endurance athletes, which could have suggested an increased bronchial blood flow or another adaptive mechanism. The absence of an adaptive mechanism could therefore contribute to airway damage observed in athletes in allowing colder but mainly dryer air to penetrate deeper in the lung.