Life expectancy and elderly population are increasing. Health professionals try to provide longevity with good quality of life for this population, through the functional independence maintenance. In this context, physical exercise has an important role, specially the strength training. The ability to produce muscle strength is positively associated with the functionality and independence of older people. Different types of strength training can lead to different neuromuscular and functional gains. These types of interventions can help health professionals to determine characteristics of training for the elderly, aiming the maintenance of their functional independence. Thus, the purpose of this study is to determine the effects of a concentric strength training versus a concentric-eccentric strength training for knee flexors and extensors on structural, neuromuscular and functional parameters in older people, as well as to investigate the effect of a detraining period. Additionally, the investigators will try to identify which structural and neuromuscular parameters of lower limbs are better related to the functionality.