In the context of pulmonary rehabilitation of COPD patients, 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. Maximal Strength Training (MST) is a kind of 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. Only a small cohort study of COPD patients was conducted, describing that MST can meaningfully improve strength and RFD, with an increase of around 32% for mechanical efficiency and a decrease of the perceived effort during submaximal job. This improvement could determine best performances in daily activities and a best quality of life. The main aims of this physiological pilot randomized controlled trail will be to evaluate feasibility and efficacy of the MST compared to standard ET on strength, effort tolerance, fatigue, economy of walking, dyspnea and risk of falls in a populations of COPD patients, in a short and middle term (6 months).