The development of critical patient-related generalized weakness is a common complication in patients admitted to an intensive care unit. The reduced muscle strength increases the time for weaning, hospitalization, the risk of infections and consequent mortality. Physiotherapy is used in these patients as a resource for the prevention of muscle weakness, atrophy and functional capacity recovery. The aim of this study was to review the literature regarding the use of exercise alone in intensive care units staying patients. Literature searches were performed using the electronic databases Medline, LILACS, CINAHL, Cochrane, High Wire Press and SciELO, from January 1998 to July 2009 and book chapters, using keywords including “critical illness”, “cinesiotherapy”, “physical therapy”, “physiotherapy”, “exercises”, “training”, “force”, “active mobilization”, “mobilization”, “ICU”, “rehabilitation”, “mobility”, “muscle strength” and “weakness”. Despite the lack of studies and methodological diversity of studies found, confirming the use of exercise alone as a therapeutic resource, its use, including early seems an alternative to prevent and reverse muscle weakness intensive care unit ICU-acquired.