Resistance Training to Prehabilitate Patients With Chronic Obstructive Pulmonary Disease

A Novel Individualized Resistance Training Program to Prehabilitate Patients With Chronic Obstructive Pulmonary Disease

Structural changes in skeletal muscles of patients with chronic obstructive pulmonary disease (COPD) have been linked to impaired muscle function, reduced exercise capacity, and increased mortality associated with this disease. Muscle dysfunction also contributes to dyspnea intensity and the ability to sustain exercise, making aerobic exercise training intolerable at the intensity and/or volume required to achieve clinically important changes. Resistance training (RT) is an attractive exercise modality because it is efficacious and more tolerable initially. No work has examined whether a short-term RT program can reduce exertional symptoms and improve exercise tolerance (dyspnea and leg fatigue) in patients with COPD.

Skeletal muscle dysfunction is common in patients with COPD and has been recognized as a contributing factor to reduced exercise capacity, health related quality of life and increased mortality associated with this disease. Several structural changes in the limb muscles of patients have previously been reported and have been linked to the known reductions in muscle strength and endurance commonly reported in COPD. Muscle dysfunction, lower extremity muscle strength, and muscle fatigue also contribute to the intensity of dyspnea and the ability to sustain exercise mostly through stimulation of type III and IV muscle afferents. As such, many patients who primarily perform aerobic exercise training as part of pulmonary rehabilitation are unable to tolerate the intensity and/or volume of exercise required to achieve clinically important changes in exercise capacity or symptom relief. Resistance training (RT) is an attractive exercise modality for patients with COPD because it is efficacious and often more tolerable initially. To our knowledge no one has examined whether similar benefits to those elicited by longer RT programs can be attained in just 4 weeks using multi-joint, multi-muscle exercises and individualized progression. If a short term RT program can improve muscle quality, enhance endurance, and reduce type III and IV afferent activity then it would reduce the drive to breathe and thus dyspnea. These adaptations would likely translate into improved exercise tolerance making it feasible to "pre-habilitate" COPD patients with tolerable RT, allowing them to achieve a higher volume/intensity of endurance training, thus making pulmonary rehabilitation more effective.

Patients with COPD will participate in 4 weeks (12 sessions) of individualized, non-linear, lower body resistance training.

Lower body resistance exercises will be prescribed in various combinations over multiple days and individually modified and progressed to achieve advances in both movement pattern, intensity, and exercise volume.

The change in the sensory intensity of dyspnea measured at an iso-time during the constant load exercise trials post RT

The change in the unpleasantness and sensory qualities of dyspnea measured at an iso-time during the constant load exercise trials post RT

Change in the amount of decline in force production after 3 minutes of electrical stimulation of femoral nerve at 25% of maximal voluntary contraction

Inclusion Criteria: Non-smokers >6 months FEV1/FVC <0.7 and lower limit of normal 30%< FEV1 pred <70% Stable (no exacerbation for >3 months) Exclusion Criteria: Cardiovascular and cerebrovascular disease Diabetes Cardiovascular contraindications to exercise Uncontrolled hypertension Currently performing regular structured exercise >3x/week for 30 minutes