High-intensity knee extensor training restores skeletal muscle function in COPD patients

Abstract

Improving reduced skeletal muscle function is important for optimising exercise tolerance and quality of life in chronic obstructive pulmonary disease (COPD) patients. By applying high-intensity training to a small muscle group, we hypothesised a normalisation of muscle function.Seven patients with COPD performed 6 weeks (3 days?week -1 ) of high-intensity interval aerobic knee extensor exercise training. Five age-matched healthy individuals served as a reference group. Muscle oxygen uptake and mitochondrial respiration of the vastus lateralis muscle were measured before and after the 6-week training programme. Initial peak work and maximal mitochondrial respiration were reduced in COPD patients and improved significantly after the training programme. Peak power and maximal mitochondrial respiration in vastus lateralis muscle increased to the level of the control subjects and were mainly mediated via improved complex I respiration. Furthermore, when normalised to citrate synthase activity, no difference in maximal respiration was found either after the intervention or compared to controls, suggesting normal functioning mitochondrial complexes.The present study shows that high-intensity training of a restricted muscle group is highly effective in restoring skeletal muscle function in COPD patients.

An Official American Thoracic Society/European Respiratory Society Statement: Update on Limb Muscle Dysfunction in Chronic Obstructive Pulmonary Disease

“…Against the hypothesis of a disease-specific myopathy are the following: (1) many functional and cellular findings in COPD are identical to those of disuse; (2) limb muscle is trainable, because training has been shown to improve muscle strength and endurance, oxidative enzyme activities, fiber cross-sectional area, and muscle capillarization, at least in some patients (307,310); (3) in a small study, highintensity aerobic interval training was shown to restore work performance and oxidative capacity of the quadriceps to a level similar to that found in sedentary individuals (312); and (4) the fact that full recovery of muscle function is unusual does not necessarily indicate a myopathy, because the duration of the training program may be too short to normalize alterations that have developed over several decades (313,314), or early ventilatory limitation may compromise the ability to tolerate sufficient muscle stimulus to improve global or cellular function (311).…”

A Cohort Study to Evaluate the Feasibility of Low Load/High Repetition Elastic Band Resistance Training for People with Chronic Obstructive Pulmonary Disease

“…The exercises within the RT regimen target muscles with decreased strength/endurance (compared to healthy individuals), muscles which are important for upper extremity activities of daily living, and muscles which are important for walking [15][16][17][18]. All exercises were executed using a single limb at a time, alternating left to right side in order to minimize the risk of a central constraint [19]. Execution of all exercise was standardized to optimize activation of targeted muscles, and included execution in the most clinically effective portion of elastic resistance [2,9,[20][21][22].…”

Ascorbate infusion increases skeletal muscle fatigue resistance in patients with chronic obstructive pulmonary disease

“…free radicals; peripheral fatigue; ascorbate SKELETAL MUSCLE DYSFUNCTION plays a prominent role in limiting exercise and activities of daily living in patients with chronic obstructive pulmonary disease (COPD) (21,22). Numerous factors, including inactivity and skeletal muscle detraining (34), mitochondrial dysfunction (9), and oxidative stress (30) have all been implicated in the skeletal muscle dysfunction associated with COPD. Of these factors, the contribution of oxidative stress to reduced exercise capacity in patients with COPD has been well documented (11,13,24).…”