Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8650816 | Respiratory Physiology & Neurobiology | 2018 | 27 Pages |
Abstract
Interval exercise delays critical mechanical-ventilatory constraints with positive consequences on Dyspnoea and exercise tolerance in COPD. We hypothesized that those advantages of interval exercise would be partially off-set in patients showing excessive ventilation (VËE) to metabolic demand (VËCO2). Sixteen men (FEV1â¯=â¯42.3â¯Â±â¯8.9%) performed, on different days, 30â¯s and 60â¯s bouts at 100% peak (on) interspersed by moderate exercise at 40% (off). Nine patients did not sustain exercise for 30â¯min irrespective of on duration. They presented with higher VËE/VËCO2 nadir (35â¯Â±â¯3 vs. 30â¯Â±â¯5) and dead space/tidal volume (0.39â¯Â±â¯0.05 vs. 0.34â¯Â±â¯0.06) compared to their counterparts (pâ¯<â¯0.05). [Lactate], operating lung volumes and symptom burden (dyspnoea and leg effort) were also higher (pâ¯<â¯0.05). Unloading off decreased the metabolic-ventilatory demands, thereby allowing 7/9 patients to exercise for 30â¯min. Increased wasted ventilation accelerates the rate at which critical mechanical constraints and limiting dyspnoea are reached during interval exercise in patients with COPD.
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Authors
Daniela M. Bravo, Ana Cristina Gimenes, Beatriz C. Amorim, Maria Clara Alencar, Danilo C. Berton, Denis E. O'Donnell, Luiz E. Nery, J. Alberto Neder,