Association of Age with Muscle Size and Strength Before and After Short-Term Resistance Training in Young Adults

Abstract

The purpose of this study was to assess the association of age with muscle mass and strength in a group of young adults before and after 12 weeks of progressive resistance training. Eight hundred twenty-six young males and females (age 24.34 ± 5.69 yr, range 18–39 yr) completed a strictly supervised 12-week unilateral resistance training program of the nondominant arm. Isometric (maximal voluntary contraction [MVC]) and dynamic strength (1 repetition maximum [1RM]) of the elbow flexors and cross-sectional area (CSA) of the biceps-brachii using magnetic resonance imaging (MRI) scans were measured before and after training. Pearson correlation coefficients were calculated for size and strength variables and age. In addition, the cohort was divided into groups according to decade of life and differences assessed by analysis of variance. Age correlated significantly and positively with all pretraining measures of muscle size and strength (CSA: r = 0.191, p < 0.001; MVC: r = 0.109, p = 0.002; 1RM: r = 0.109, p = 0.002). Age was not related to the training-induced changes in CSA or MVC but was negatively associated with the change in 1RM (r = −0.217, p < 0.001). The study indicates that age does have a significant positive relationship with muscle size and strength in untrained young adults. Although age was negatively associated with improvements in 1RM, the effect of age was small relative to the improvements induced through resistance training, thus suggesting age does not limit response to training in any practical way during early adulthood.

Chronic Intrinsic Transient Tracheal Occlusion Elicits Diaphragmatic Muscle Fiber Remodeling in Conscious Rodents

“…However, the oldest ITTO-20 animals were in early to middle adulthood, while the ITTO group was in late adolescence [58]. Thus, we do not expect that aging inhibited the training responses of ITTO-20 animals, supported by the lack of significant differences between the ITTO and ITTO-20 groups [59]. While rat body mass and fiber size increase through late adulthood [60], [61], we did not find larger fibers in the older ITTO-20 than ITTO animals.…”

Highlights from the Functional Single Nucleotide Polymorphisms Associated with Human Muscle Size and Strength or FAMuSS Study

“…While genetic modifiers of muscle strength and size were a priority for FAMuSS, other factors were also explored, such as sex [7], age [8], and BMI [9, 10]. However, the primary focus of this section is to summarize the findings regarding genetic influences on muscle size and strength at baseline and following RT.…”

“…The high degree of variation that we observed in muscle size and strength responses to RT that were sex specific allowed us to test for various factors that influenced these phenotypes at baseline and in response to RT. While genetic modifiers of muscle strength and size were a priority for FAMuSS, other factors were also explored, such as sex [ 7 ], age [ 8 ], and BMI [ 9 , 10 ]. However, the primary focus of this section is to summarize the findings regarding genetic influences on muscle size and strength at baseline and following RT.…”

Muscle System Changes

“…79 Training needs to be specific to how the muscle is expected to function, statically for holding, for power or for endurance, in order to see improvements. Training also needs to be specific to the type of task being performed.…”