title: Effects of oxone inhalation on work performance and VO2 max.
abstract: Ozone (O3) at near ambient smog alert levels has previously been shown to cause alterations in pulmonary function and exercise response in humans. The present study was designed to investigate the effects of O3 administered during graded bicycle exercise to volitional fatigue on work performance and maximal oxygen uptake (VO2max). Nine subjects performed three tests each while breathing either 0.00, 0.15, or 0.30 ppm O3. Forced vital capacity, residual volume, maximal midexpiratory flow rate, and forced expiratory volume in 1 s were assessed before, immediately after, and 4 h after exercise. O3 exposure resulted in no significant effect on maximal work rate, anaerobic threshold, or any pulmonary function parameter. However, maximal expired minute ventilation was decreased (P less than 0.05) in a dose dependent fashion. Thus, exercise ventilation during maximal work was a more sensitive indicator of the effects of O2 exposure than were standard pulmonary function tests. Although subjective symptoms of discomfort were reported more frequently with increased O2 level, it was concluded that exposure of healthy young men to as much as 0.30 ppm O2 for no more than 30 min of progressively incremented exercise to volitional fatigue, is insufficient to cause a significant decrease in work capacity or V02 max.
mesh_terms: D000328:Adult; D006801:Humans; D008168:Lung / Q000502:physiology; D008176:Lung Volume Measurements; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects*; D010126:Ozone / Q000494:pharmacology*; D005082:Physical Exertion / Q000187:drug effects*; D012119:Respiration
chemical_list: D010126:Ozone