Low Load, High-repetitive Elastic Band Resistance Training in COPD

Recent work have shown that low load, high-repetitive single limb resistance training, if compared to a control, can increase limb muscle function and functional exercise capacity in patients with chronic obstructive pulmonary disease (COPD) while avoiding the occurrence of limiting exertional symptoms. However, no comparison to another exercise regimen have been performed. In addition neither the intramuscular nor the mechanism of this exercise regimen have been investigated and represents the aim of the proposed project. We will in a prospective, assessor-blind; block randomized controlled, parallel-group trial compare single-limb to two-limb low load, high-repetitive resistance training in patients with severe and very severe COPD

The research hypothesizes are:

* that single-limb low-load high-repetitive resistance training will provide larger gain in the 6-min walking distance than two-limb low-load high- repetitive resistance training in patients with severe to very severe (stage III-IV) COPD.
* that eight weeks of single limb training should also be associated with larger physiological (increased muscle endurance, less muscle fatigue and deoxygenation) and structural (muscle protein synthesis, fiber-type distribution and capillarization) muscle adaptations to training, lower cardio- respiratory demand, as well a greater increase in health-related quality of life in comparison to two-limbs simultaneous training.

We will also compare the groups at baseline to investigate the acute effects and mechanisms of single-limb to two-limb low load, high-repetitive resistance training, a comparison that also will include healthy matched controls.

The research hypothesizes are:

* that involving a large muscle mass during exercise (e.g., two-limb low load, high-repetition resistance training) compared to involving a small muscle mass during training (e.g., single limb low load, high-repetition resistance training) would lead to larger restraints on the cardiorespiratory system in patients with severe to very severe COPD. Conversely, single limb interventions should produce less dyspnea and more muscle deoxygenation and fatigue than two-limb simultaneous exercise while healthy controls will be able to perform both legs/arms exercise without a central constraint, and no negative consequences on muscle fatigue or exercise stimulus.


Eligibility Criteria:
Inclusion criteria (COPD):

* Age: \> 40
* Cumulative (current or ex) smoking history \>10 pack-years
* COPD with non-reversible airflow obstruction corresponding to GOLD 3 and 4

Exclusion Criteria:

* Recent exacerbation (\< 6 weeks)
* Neuromuscular and/or orthopedic disorders that compromises participation to an exercise program
* Recent cancer
* Unstable cardiac disease and cardiac stimulator
* Asthma
* Low body weight or obesity (Body Mass Index \< 20 Kg/m2 and or \> 30kg/m2)
* Significant hypoxemia at rest (SaO2 \<85%)
* a daily dose \> 10mg of systemic prednisone.

Inclusion criteria (Healthy controls)

* Age: \> 40
* Normal pulmonary function tests.

Exclusion criteria

* Neuromuscular and/or orthopedic disorders that compromises participation to an exercise program
* Physically active (\>9) according the Voorips questionnaire.