Secondary outcome measures
Isometric handgrip force will be measured with a hydraulic handheld dynamometer (Yamar Preston, Jackson MI). Peak handgrip force (in Newton) will be assessed at the dominant side with the elbow at 90 degrees flexion,
with the underarm and wrist in neutral position [48]. Isometric knee extension and shoulder abduction force will be measured in standardised positions by a handheld dynamometer by means of the break method [42,49]. Peak torques will be measured at the dominant side according to Andrews et al. [49]. At least three attempts will be performed for all muscle tests. Self-reported daily physical activity will be assessed by the brief physical activity assessment tool [50]. Objective daily physical activity will be measured during 3 consecutive days and nights with an accelerometer-based
activity monitor (Dynaport; McRoberts BV). Data of both intensity of movement and duration will be collected, like steps per day, total active time per day, time spent in moderate intense physical activities and vigorous activities and physical activity level (PAL). All patients will be carefully instructed on how the activity monitor should be positioned and they will receive a manual with clear instructions and figures. They will also have to fill out a checklist to verify if their day was a
representative one and to indicate any possible hindrance of the activity monitor.
The level of dyspnoea will be assessed by the Medical Research Council (MRC) dyspnoea score [51]. Specific Health Related Quality of Life (HRQL) will be assessed by means of the Clinical COPD Questionnaire (CCQ) [52,53] and the Chronic Respiratory Questionnaire (CRQSR) [54-56]. The global perceived effect (GPE) of the treatment according to the patients will be measured on a GPE scale [57,58]. Furthermore, the following baseline characteristics will be measured, height, weight, Body Mass Index (BMI) and level of motivation by means of the questionnaire (Dutch translation) according to Miller and Rollnick et al. [59-61].