Vmax encore 229

Participants reported to the laboratory on two separate occasions separated by at least 48 h. Participants were instructed to avoid caffeine for 8 h and exercise for 24 h prior to each testing session. Session 1 involved anthropometric measurements and pulmonary function tests (Vmax Encore 229 with V62J Autobox; CareFusion, CA, USA), which were performed in accordance with standard recommendations (Miller et al., 2005 (link); Wanger et al., 2005 (link)). Inspiratory muscle strength was measured using a semi‐occluded mouthpiece connected to a calibrated differential pressure transducer (DP15‐34; Validyne Engineering, CA, USA) as recommended (Laveneziana et al., 2019 (link)). Pulmonary function and inspiratory muscle strength results were presented in absolute units and as a percentage of predicted values (Black & Hyatt, 1969 (link); Gutierrez et al., 2004 (link); Tan et al., 2011 (link)). Participants were then familiarized with the scales used to record dyspnea during IPTL as well as the IPTL protocol itself. Session 2 was the primary testing session where participants engaged in IPTL until task failure. Diaphragm contractile function and voluntary activation were measured during session 2 only.

Spirometry and plethysmography were performed using a commercially available system (Vmax Encore 229, V62J Autobox; CareFusion) according to standard recommendations. The incremental cycle test to exhaustion was performed on an electromagnetically braked ergometer. Participants began at a work rate of 80 W (women) or 120 W (men) and work increased every 2 min by 20 W for both sexes until volitional exhaustion. Flows, volume, and esophageal pressures (balloon‐tipped catheter) were obtained using previously described methods (Dominelli et al., 2015). Following exercise, subjects completed forced vital capacity (FVC) maneuvers to ensure forced expired volume in 1 s (FEV₁) was not reduced during exercise. All raw data collected on the first day of testing were recorded at 200 Hz continuously using a 16‐channel analog‐to‐digital data acquisition system (PowerLab/16SP model ML 795, ADIinstrument, Colorado Springs, CO) and stored on a personal computer for analysis.