Submaximal Eccentric Cycling in People With COPD

Background Eccentric cycling (ECC) may be an attractive exercise method in COPD because of both low cardiorespiratory demand and perception effort compared with conventional concentric (CON) at matched mechanical loads. However, it is unknown whether ECC can performed by individuals intensity able to cause sufficient metabolic stress improve aerobic capacity. Research Question What are the cardiopulmonary responses people healthy volunteers when CON loads? Study Design Methods Thirteen (mean ± SD age, 64 9 years; FEV1, 45 19% predicted; BMI, 24 4 kg/m2; oxygen uptake peak [V?O2peak], 15 3 mL/kg/min) age-matched control participants (FEV1, 102 13% 28 5 V?O2peak, 23 mL/kg/min), up six 4-min bouts loads increasing intensity. In addition, 12 underwent quadriceps muscle biopsies before after 20 min 65% power. Results At loads, uptake, minute ventilation, heart rate, systolic BP, respiratory exchange ratio (all P < .001), capillary lactate, perceived breathlessness, leg fatigue (P .05) were lower groups during than CON. Muscle lactate content increased = .008) phosphocreatine decreased .012) COPD, which was not evident ECC. Interpretation Cardiopulmonary blood submaximal less equivalent workloads patients, this confirmed a level patients. Submaximal well tolerated allowed greater work ventilatory cost. training intervention based on unlikely stimulate cardiovascular adaptation same extent as