News & Views from the Editor-in-Chief - L. Bruce Gladden
Our journal regularly publishes excellent papers, and this month is no exception; as usual, I am highlighting three of them. First, Leahy et al. observed the effects of chlorinated inspirate and swimming in provoking exercise-induced bronchoconstriction in high-performance swimmers. The group designed a modified eucapnic voluntary hyperpnea (EVH) test in which swimmers inhaled air that was collected from just above a chlorinated pool. Changes in pulmonary function resulting from the modified EVH test were compared to a typical clinical EVH test and a swimming challenge. The ambient conditions in which swimmers train and compete (i.e., humid, warm, chlorinated air) elicited less of an airway response. Given the high rates of exercise-induced bronchoconstriction in swimmers, this study calls into question the appropriateness of using the standard EVH test for detecting the phenomenon in aquatic athletes.
Second, Wagner and colleagues addressed an omnipresent challenge when assessing O2max as a clinical vital sign or as a critical outcome in research studies—the distinction between those individuals who reached their physiological limit and therefore O2max and those who did not. The study was based on cardiopulmonary exercise tests (CPETs) of healthy participants across the life span from 20 to 90 years from the COmPLETE study cohort. For the first time, data-based optimal secondary exhaustion criteria for maximal exercise were established. The results suggest the use of specific, high and age-stratified criteria based on heart rate and respiratory exchange ratio or a multi-parameter score to distinguish between a maximal and a submaximal effort. Lower criteria than those suggested in this article are likely to result in false positive results. Application of these new, higher criteria have the potential to improve the precision of O2max assessment in research and clinical practice.
Finally, Schmidt and colleagues examined whether a chronic reduction in oxygen transport capacity through carbon monoxide (CO) inhalation could produce adaptation effects comparable to those of high-altitude exposure. Subjects inhaled a small amount of CO five times a day for 3 weeks, which increased carboxyhemoglobin levels by about 5% over the entire day. After three weeks, hemoglobin mass increased by 4.8% which correlated well with improvements in O2max. The authors concluded that low-dose CO inhalation resulted in hemoglobin mass increases similar to an altitude exposure of 2500 m. Despite this interesting physiological response, the authors strongly caution that examinations of the ethical and safety concerns are warranted prior to any consideration of implementing low-dose CO inhalation in clinical/athletic settings.
L. Bruce Gladden
School of Kinesiology