Physiological Response to Moderate Exercise Workloads in a Pulmonary Rehabilitation Program in Patients With Airflow Obstruction: Outcome

Physiological Response to Moderate Exercise Workloads in a Pulmonary Rehabilitation Program in Patients With Airflow Obstruction: OutcomeWe are aware however that the reduction in Ve could be multifactorial and could relate to diverted substrate utilization or diminished catecholamine production, or that it could be due to the increased efficiency of peripheral muscle oxygen extraction, with lower resultant lactate and CO2 generation from bicarbonate buffering. Although the significant correlation (r = 0.63) that was found between changes in Ve and VC02 suggests that a considerable component of the reduction in Ve is related to decreased VC02 after training, we also cannot exclude the possibility of a more efficient breathing pattern (reduced physiologic dead space/tidal volume ratio) and decreased hyperinflation following a training program being contributory. In the absence of physiologic dead space/tidal volume ratio measurements, we cannot confirm the previous observations.
There are several other potential explanations for the reduction in VE following training. First, there may be a reduced metabolic requirement for a given exercise task, as evidenced by the lower V02 at an identical WR. Second, since VC02 decreased to the same extent as V02 (from 8 to 9%; Table 3), the enhanced mechanical efficiency may also have contributed to the fall in the ventilatory requirement. However, at WRs above the AT, physiologic training is associated with reduced lactate production and, in turn, lower V02 requirements (up to approximately 10%) and lower bicarbonate-elevated VC02.> In contrast to a comparative study, we did not evaluate serum lactate. doxycycline generic

A review of many pulmonary rehabilitation programs identified only one program that featured a variable training frequency of two or fewer sessions per week. While peak V02 and submaximal exercise performance improved following rehabilita-tion, there was no evidence of a lower ventilatory requirement at a given WR. Recently, studies featuring twice-weekly exercise rehabilitation sessions for 7 to 12 weeks reported significant improvements in exercise performance assessed by simple walking tests. The current study confirms the effects of twice-weekly training programs on enhancing exercise performance, not only in terms of objectively measured peak physiologic responses, but that such effects are accompanied by a reduced ventilatory requirement at a submaximal level of exercise,