Resistance Exercise to Prevent and Manage Sarcopenia and Dynapenia

Abstract

For well over twenty centuries the muscle wasting (sarcopenia) and weakness (dynapenia) that occurs with old age has been a predominant concern of 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 can have on increasing muscle strength, muscle size and functional capacity in older adults. In this review article we discuss how resistance exercise training 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 resistance exercise training program designed for the management and prevention of sarcopenia and dynapenia, including example training programs for the beginner through 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.

Keywords: Aging; Dynapenia; Exercise; Muscle; Sarcopenia; Strength; Weakness.

Figure 1. Higher intensity resistance exercise training is associated with greater improvements in muscle strength (Figure 1A), and higher volume resistance exercise training is associated with greater improvements in lean body mass (LBM) (Figure 1B)

Figure 1A: Peterson et al. reported in a meta-analysis that with each incremental increase in exercise intensity from low intensity (<60% of 1-RM), low/moderate intensity (60–69% of 1-RM), moderate/high intensity (70–79% of 1-RM) to high-intensity (≥80% of 1-RM) training the average percent change in strength was 5.3% (Peterson et al., 2010). Figure 1B: LBM change by training volume (defined as sets per session) when weighted by the number of subjects in a given study using a meta analytical approach (Peterson et al., 2011). Figure 1A was created from data presented in Peterson et al., Resistance exercise for muscular strength in older adults: a meta-analysis. Ageing Research Reviews, 226–237, 2010. Figure 1B was reprinted with permission by Peterson et al., Influence of resistance exercise on lean body mass in aging adults: a meta-analysis. Med Sci Sports Exerc, 43: 249–258, 2011.

Figure 2. Conceptual interactions between physical activity, sarcopenia, dynapenia, fatigability, exercise tolerance, and physical function (2A) and how progressive resistance exercise training can modulate these various phenotypic factors (2B)

Note that other influences, such as nutritional, cognitive, and psychological factors, are not shown for clarity. Adapted with permission from Liu and Fielding. Exercise as an intervention for frailty. Clin Geriatr Med. 27:101–10, 2011.

Figure 3

Relationship between the number of repetitions untrained (3A) and trained (3B) healthy adults were able to perform using free weights at four different resistance exercise intensities (60, 80 and 90% of 1-RM) for the squat (square), bench press (triangle), and arm curl (circle). Relationship between the number of repetitions untrained (3C) and trained (3D) healthy adults were able to perform using resistance exercise machines at three different resistance exercise intensities (60, 80 and 1-RM) for the leg press (square), chest press (triangle), and arm curl (circle). Data represents the mean response for each exercise and intensity, respectively. Figure 3A and 3B created from data presented in Shimano et al., Relationship between the number of repetitions and selected percentages of one repetition maximum in free weight exercises in trained and untrained men. J Strength and Conditioning Research. 20: 819–823, 2006. Figure 3C and 3D created from data presented in Hoeger et al., Relationship between repetitions and selected percentages of one repetition maximum: a comparison between untrained and trained males and females. J Applied Sport Science Research. 4: 47–54, 1990.