Tiller NB, Turner LA, Hart J, Casaburi R. Airflow dynamics and exhaled-breath temperature following cold-water ingestion.
Respir Physiol Neurobiol 2020;
284:103564. [PMID:
33141065 DOI:
10.1016/j.resp.2020.103564]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 09/22/2020] [Accepted: 10/12/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION
Drinking cold water evokes decreases in spirometric indices of lung function. We studied whether this could be explained by changes in exhaled-breath temperature (EBT), airflow dynamics, and spirometer measurement sensitivity.
METHODS
In a randomized/crossover design, 10 healthy adults consumed 1000 mL refrigerated water (2.1 ± 0.64 °C) or water at room temperature (19.4 ± 0.5 °C), with EBT assessed at baseline and at 5, 10, 15 and 30-min post-ingestion. The influence of EBT on pneumotachograph measurement characteristics was modelled using computational fluid dynamics (CFD).
RESULTS
At 5-min post-ingestion, EBT was lower (p < 0.001) following the ingestion of cold water versus water at room-temperature (31.7 ± 1.1 vs. 33.0 ± 0.9 °C), and remained lower until 30-min post-ingestion. At a flow of 8 L s-1, a decrease in EBT of 2.1 °C (as observed following cold-water ingestion) was modelled to underpredict lung volume by 0.7%.
CONCLUSIONS
Cold water reduces EBT below baseline but effects pneumotachograph measurements only negligibly. Therefore, decreased lung function following cold-water ingestion likely has a physiological explanation which warrants further study.
Collapse