Effect of resistance training frequency on physiological adaptations in older adults

Resistance training is an effective way to achieve optimal gains in muscle mass and strength and has also been well documented in attenuating various forms of skeletal muscle wasting (e.g., sarcopenia). Moreover, it has been demonstrated that with appropriate training, older adults can reverse strength and muscle mass deficits to younger levels. To attain maximal benefits, careful manipulation of training variables, such as intensity, volume and frequency, is required. Although training intensity and training volume have been extensively studied, there is only scarce information available on the adaptive responses to frequency manipulations in older populations. Thus, we compared the effects of short-term (8 weeks) resistance training programs performed either 2 days/week (n = 15, 7 males, 8 females) or 3 days/week (n = 14, 4 males, 10 females) on muscle mass, upper- and lower-body strength and functional abilities in individuals aged > 60 years. Chest press strength increased in both the 2 times/week and 3 times/week groups over the 8-week training period by 20.84% and 20.18%, respectively. Lower-body (leg press) strength also showed improvements in both groups: 22.34% in the 2 times/week group and 28.12% in the 3 times/week group. There was a slight, but nevertheless significant gain of lean body mass from pre- to post-training (2.4% and 1.9% for the 2 days and 3 days groups, respectively). However, functional performance remained unchanged in the groups. We found that short-term resistance training 2 times/week or 3 times/week elicited comparable muscle strength and lean body mass adaptations in older adults.