Maximal oxygen consumption, per exercise modality, in asthmatics with normal spirometry

Abstract

Asthma is characterized by intermittent airway obstruction with chronic inflammatory processes leading to airway remodeling. The objective was to determine if maximal oxygen consumption (VO2max), per exercise modality, was altered by airway remodeling. Fourteen participants (N = 14), eight “Normals” (N = 8, age = 22 ± 3 y, body fat = 12.2 ± 3.7%) and six “Asthmatics” (N = 6, age = 23 ± 5 y, body fat = 19.6 ± 4.0%) underwent three VO2max trials, one via treadmill (TM), a second, seated on a cycle ergometer (CE, Sit‐CE), and a third, standing on a CE (Stand‐CE). ANOVA (group by trial) demonstrated significant (p = 0.05) differences by group on VO2max (Normals TM = 46.2 ± 10.5 ml.kg−1.min−1, Sit‐CE = 38.5 ± 8.5, Stand‐CE 41.6 ± 10.0; Asthmatics TM = 32.5 ± 8.0, Sit‐CE = 23.4 ± 8.6, Stand‐CE = 26.3 ± 8.6), VO2max‐minute ventilation (Normals TM = 115.6 ± 27 L.min−1, Sit‐CE = 105.4 ± 30, Stand‐CE = 107.2 ± 30; Asthmatics TM = 88.5 ± 13, Sit‐CE = 65.4 ± 12, Stand‐CE = 87.1 ± 32), but not VO2max‐heart rate (Normals TM = 184 ± 10 b.min−1, Sit‐CE = 169 ± 11, Stand‐CE = 174 ± 10; Asthmatics TM = 185 ± 8, Sit‐CE = 163 ± 14, Stand‐CE = 180 ± 14). Spirometry was normal pre/post trials. In conclusion, Asthmatics low VO2max, most prominent during CE, was not due to airway remodeling, but rather, likely caused by exercise avoidance per fear of airway obstruction. This study was funded by an internal grant from the University.