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.

Similar Airway Function after Volitional Hyperpnea in Mild-Moderate Asthmatics and Healthy Controls

“…FEV 1 declines after HYP 1 were significantly smaller than those after HYP 2 despite a similar total HYP duration. This is in line with previous studies in asthmatics [29-31], suggesting the development of a refractory period as a result of the activity during preceding HYP bouts.…”

Exercise-induced bronchoconstriction, allergy and sports in children

“…This temporary resistance is believed to occur due to the tachyphylaxis of airway smooth muscles to bronchoconstriction-inducing mediators [ 90 ]. Both continuous and intermittent warm-up exercises have been shown to reduce EIB [ 91 , 92 ].…”

Asthma and exercise‐induced bronchoconstriction in athletes: Diagnosis, treatment, and anti‐doping challenges

“…As an alternative, isolated warmup involving respiratory muscles may provide similar protective effects against bronchoconstriction as whole-body exercise without compromising subsequent performance. 76 Apparel such as face masks may also be used to prevent bronchoconstriction triggered by breathing large volumes of cold and dry air when exercising outdoors. So-called heat and moisture exchanger face masks retain heat and moisture and thus help prevent dehydration of the airways.…”