title: Pre-Exercise Hyperpnea Attenuates Exercise-Induced Bronchoconstriction Without Affecting Performance.
abstract: Whole-body warm-up exercises were shown to attenuate exercise-induced bronchoconstriction (EIB). Whether intense pre-exercise hyperpnea offers similar protection and whether this might negatively affect exercise performance is unknown. Nine subjects with EIB (25±5 yrs; forced expiratory volume in 1s [FEV1], 104±15% predicted) performed an exercise challenge (ECh) followed-after 30min-by a constant-load cycling test to exhaustion. The ECh was preceded by one of four conditions: by i) control warm-up (CON) or by 10min of normocapnic hyperpnea with partial rebreathing at either ii) 50% (WU50) or iii) variable intensity (8x 30s-80%/45s-30%; WU80/30), or at iv) 70% (WU70) of maximal voluntary ventilation. FEV1 was measured at baseline and in 5-min intervals until 15min after CON/warm-up and 30min after ECh. None of the warm-up conditions induced EIB. The maximal post-ECh decrease in FEV1 was -13.8±3.1% after CON, -9.3±5.0% after WU50 (p = 0.081 vs. CON), -8.6±7.5% after WU80/30 (p = 0.081 vs. CON) and -7.2±5.0% after WU70 (p = 0.006 vs. CON), and perception of respiratory exertion was significantly attenuated (all p≤0.048), with no difference between warm-up conditions. Only after CON, FEV1 remained significantly reduced up to the start of the cycling endurance test (-8.0±4.3%, p = 0.004). Cycling performance did not differ significantly between test days (CON: 13±7min; WU50: 14±9min; WU80/30: 13±9min; WU70: 14±7min; p = 0.582). These data indicate that intense hyperpnea warm-up is effective in attenuating EIB severity and accelerating lung function recovery while none of the warm-up condition do compromise cycling performance.
authors.affiliation: Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland.
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Eichenberger
authors.affiliation: LungenZentrum Hirslanden, Zurich, Switzerland.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Scherer
authors.affiliation: Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich, Zurich, Switzerland.|Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Spengler
mesh_terms: D000328:Adult; D016084:Bronchoconstriction / Q000502:physiology*; D015444:Exercise; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006339:Heart Rate; D006801:Humans; D008168:Lung / Q000502:physiology; D008297:Male; D013550:Swimming; D063996:Warm-Up Exercise; D055815:Young Adult