Study on Impact of Maximal Strength Training in Patients With COPD: Physiological and Clinical Implications

Exercise intolerance is a cardinal problem existing in patients with Chronic Obstructive Pulmonary Disease (COPD). Moreover, skeletal muscle dysfunction is a common extra-pulmonary manifestation, leading to fatigue, decrease in activity of daily living (ADL) performance and quality of life and increase of risk of falls, mainly in older patients. In the context of pulmonary rehabilitation, recent guidelines and metanalysis describe that Resistance Training (RT) can be successfully performed alone or in conjunction with Endurance Training (ET) without evidence of adverse events.

As concern the RT programs, metanalysis in COPD describe that training have been mainly performed with the lower limbs and the training intensities are heterogeneous, generally ranging from 40% to 70% of 1-Repetition Maximum (1-RM).

Maximal Strength Training (MST) is a RT typically performed at ~85-90% of 1RM with maximal velocity to be developed in the concentric phase. Recent literature indicates a significant amelioration on the Rate of Force Development (RFD) after MST in healthy subjects, post-menopausal woman and older populations.

When comparing to the conventional ET, MST generates a little change in muscle mass (no hypertrophy), but a much greater improvement in the RFD. It has been described that neural adjustments play a major role in the MST-induced adaptations. MST is also well documented to improve aerobic endurance by improving walking work efficiency.

Although the mechanisms at the base of MST effect on the mechanical efficiency have not been completely clarified, there is evidence that changes in the relationships between power and speed bring to a longer relaxation phase inside the cycle of job, improving the recovery between contractions.