For well over 20 centuries, the muscle wasting (sarcopenia) and weakness (dynapenia) that occurs with old age has been a predominant concern for mankind. Exercise has long been suggested as a treatment to combat sarcopenia and dynapenia, as it exerts effects on both the nervous and muscular systems that are critical to positive physiological and functional adaptations (e.g., enhanced muscle strength). For more than two decades, scientists have recognized the profound role that progressive resistance exercise training (RET) can have on increasing muscle strength, muscle size, and functional capacity in older adults. In this review article, we discuss how RET can be used in the management and prevention of sarcopenia and dynapenia. We first provide an overview of the evidence for this notion and highlight certain critical factors—namely, exercise intensity, volume, and progression—that are key to optimizing the resistance exercise prescription. We then highlight how many, if not most, of the commonly prescribed exercise programs for seniors are not the “best practices” and subsequently present easy-to-read guidelines for a well-rounded RET program designed for the management and prevention of sarcopenia and dynapenia, including example training programs for the beginner through programs for the advanced senior resistance exerciser. These guidelines have been written for the academician as well as the student and health-care provider across a variety of disciplines, including those in the long-term care industry, such as wellness instructors or activity directors.