Objectives: Verify the effect of resistance training (RT) in muscle mass and muscle strength in older adults. Methods: Randomized Controlled Trials (RCT) published between 2005 and 2015, with a study population aged 65 and up that went through an RT based intervention were analysed. Body composition should be assessed by Dual Energy X-ray Absorptiometry or Computed Tomography Scan. Internal validity of each article was assessed using the PEDro scale. Results: Five RCTs whit score of 5/10 met the inclusion criteria and globally 162 participants were assessed. Each study was based on a RT program of 6-16 weeks of 2-3times/week. Discussion Main results show that high intensity and even low intensity RT, increased muscle mass, cross sectional area, strength of the quadriceps and functionality. RT has shown great outcomes in preventing sarcopenia. Results magnitude is proportional to RT characteristics.