•  
  •  
 

EFFECTS OF HYDRATION ON EXERCISE-INDUCED BRONCHOCONSTRICTION IN THE COLD IN HIGH-VENTILATION COLLEGIATE ATHLETES

Abstract

Exercise-induced bronchoconstriction (EIB) occurs due to drying and irritation of the airways and is characterized by reduced forced expiratory volume (FEV1) and forced vital capacity (FVC). EIB is more prevalent in high-ventilation athletes, exacerbated by cold air, and evidence suggests it is diminished through increased hydration in warm conditions. PURPOSE: To determine whether increased hydration would diminish EIB following high-intensity exercise in the cold. METHODS: 7 male and 3 female D1 collegiate rowers (20.3 ± 1.4 yrs.) performed a graded treadmill test to exhaustion to determine maximal ventilation and to set intensity for experimental trials. Subjects recorded fluid intake for 7 days prior to the first experimental trial. Two trials were performed in a counterbalanced order. The baseline (BL) trial was performed without manipulating the subjects’ normal fluid intake, while the hydration (HYD) trial was performed following 7 days of consuming an additional 1.1 L of water/day and 1.2 L of saltwater (0.003% w/v NaCl) 120 minutes prior to the trial. Plasma osmolarity (POsm) was assessed and pre-exercise spirometry was performed prior to each trial. The exercise protocol consisted of a 10-min. warm-up, followed by 8 min. of running at the final speed achieved in the graded test in an environmental chamber set to at -16℃ and 40% humidity. The spirometry test was repeated 3 min. post-exercise in ambient conditions and compared to pre-exercise values to assess EIB. Data was analyzed using repeated measures ANOVA and paired sample t-tests (α set at £0.05). RESULTS: There was no difference in POsm between BL (296.3 ± 3.8 mOsM) and HYD (294.0 ± 5.2 mOsM, p= 0.285). Subjects consumed an additional 0.81 ± 0.99 L/day of fluid prior to HYD (p= 0.04). Exercise in the cold lead to a 4.88% decrease in FEV1 (4.1 ± 0.34 vs. 3.9 ± 0.33 L, p= 0.027) and a 4.73% decrease in FVC (4.44 ± 0.35 vs. 4.23 ± 0.32 L, p= 0.017). Hydration status did not impact pre- vs. post-exercise FEV1 (p= 0.337) or FVC (p= 0.534). CONCLUSION: High-ventilation exercise in the cold did induce bronchoconstriction, thereby demonstrating modest EIB. Hydration status did not appear to impact prevalence or magnitude of EIB following exercise in the cold as had been previously reported in warm conditions. These findings reinforce that cold air is a strong stimulus for EIB.

This document is currently not available here.

Share

COinS