An Evaluation of Standardizing Target Ventilation for Eucapnic Voluntary Hyperventilation Using FEV₁

Abstract

Athletes are required to provide objective documentation of exercise‐induced bronchoconstriction (EIB) to use β₂‐agonists during Olympic competition. A positive response to bronchial provocation by eucapnic voluntary hyperventilation (EVH) is considered acceptable confirmation of EIB. Thirty times forced expiratory volume in the first second (FEV₁) is recommended as EVH target ventilation (TV), an intensity intended to estimate 85% of maximal voluntary ventilation (MVV). There is a paucity of data examining the accuracy of predicting MVV from FEV₁ in elite athletes. The purpose of this study was to evaluate the efficacy of 30 × FEV₁ as standardized EVH TV. Maximal minute ventilation during exercise (VEmax) and pulmonary function of 78 elite winter athletes (25 males, 53 females; 25 EIB positive, 53 normal) were analyzed retrospectively. Adequacy and variability of the equation was ascertained by examining the ratio of EVH TV (30 × FEV₁) to VEmax. VEmax was 99 ± 11% of predicted MVV (35 × FEV₁) and was positively related (r = 0.85, p ≤ 0.05). TV was 88 ± 9% of VEmax (range: 64–109). For elite athletes, the high variability in 30 × FEV₁ to standardize TV for EVH may result in under‐diagnosis for low‐end outliers. Since VEmax of elite endurance athletes is typically known (via maximal aerobic testing) we recommend 85% VEmax as a more accurate and reliable method to establish EVH TV for this group; if VEmax is not available, then 85% of measured MVV may be used.

KEYWORDS:

• Asthma
• Bronchospasm
• Exercise‐induced bronchoconstriction
• Isocapnic hyperpnea
• Olympics