et al., 2011 ). To mimic the overt physical inactivity experienced during hospitalization, while separating the catabolic, disease-related effects from the intrinsic effects of skeletal muscle disuse, we subjected a cohort of healthy, community-dwelling older adults to a 7-day bed rest (BR) protocol
Emily Arentson-Lantz, Elfego Galvan, Adam Wacher, Christopher S. Fry and Douglas Paddon-Jones
James Fell and Andrew Dafydd Williams
Recovery from exercise is integral to the physical training process. There is a perception among older athletes that aging negatively affects the recovery process. Plausible arguments for an impaired recovery with aging are a greater susceptibility of older muscle to exercise-induced skeletal-muscle damage and a slower repair and adaptation response. Differences in the physical activity level of the research participants are rarely considered, however. This makes it difficult to differentiate the respective roles of declining physical activity and aging on the recovery process. Furthermore, the type of exercise used to induce damage and monitor recovery is often not indicative of a normal training stimulus for athletes. This review discusses the effects of aging on skeletal-muscle damage and recovery processes and highlights the limitations of many of these studies with respect to older athletes. Future research should use an exercise intervention representative of a normal training stimulus and take the physical activity level of the participants into account.
Élvio R. Gouveia, Bruna R. Gouveia, José A. Maia, Cameron. J. Blimkie and Duarte L. Freitas
The aims of this study were to describe age- and sex-related differences in total body skeletal muscle (TB-SM) mass and to determine the variance explained by physical activity (PA). This cross-sectional study included 401 males and 402 females, aged 60–79 years. TB-SM was determined by dual-energy x-ray absorptiometry (DXA) and PA by Baecke questionnaire. Statistical analysis included t test, ANOVAs, Pearson correlations, and multiple regression analysis. TB-SM mass was higher in the youngest age group when compared with the oldest in males and females. Males had greater TB-SM values than females. PA made a significant and positive contribution to the variation in TB-SM, β = 0.071; p = .016. Sex, height, fat mass, and PA explained 77% of the variance in TB-SM. The oldest cohorts and females had lower TB-SM than the younger cohorts and males. This study suggests that PA exerts a significant role in the explanation of TB-SM.
Ando Pehme, Karin Alev, Priit Kaasik and Teet Seene
The purpose of this study was to investigate the effect of compensatory hypertrophy (CH), heavy-resistance exercise training (HRET), and simultaneous CH and HRET on fast-twitch skeletal-muscle myofibrillar-protein synthesis, myosin heavy-chain (MHC) turnover rate, and MHC-isoform composition in young and old rats. In young animals all treatments intensified myofibrillar-protein synthesis, whereas in old animals with CH protein synthesis remained unchanged. The relative content of MHC I and IID in plantaris muscle increases with age, and the relative content of MHC IIB decreases. HRET and simultaneous CH and HRET decreased the proportion of MHC IIB and IIA and increased that of MHC IID in young rat muscle. In old rat muscle, relative content of MHC IID decreased and that of MHC IIB increased. CH decreased relative content of MHC IIB in both age groups and of MHC IIA in old animals. Relative content of MHC IID increased in both groups, and of MHC IIA, in young animals. MHC in plantaris of young rats turned over much faster in all types of mechanical loading but in old rats only during HRET and its combination with CH.
Nai-Hsin Meng, Chia-Ing Li, Chiu-Shong Liu, Wen-Yuan Lin, Chih-Hsueh Lin, Chin-Kai Chang, Tsai-Chung Li and Cheng-Chieh Lin
To compare muscle strength and physical performance among subjects with and without sarcopenia of different definitions.
A population-based cross-sectional study.
857 community residents aged 65 years or older.
Sarcopenia was defined according to the European Working Group of Sarcopenia in Older People consensus criteria. Dual-energy X-ray absorptiometry measured lean soft tissue mass. Sarcopenic participants with low height-adjusted or weight-adjusted skeletal muscle index (SMI) were classified as having h-sarcopenia or w-sarcopenia, respectively. Combined sarcopenia (c-sarcopenia) was defined as having either h- or w-sarcopenia. The participants underwent six physical performance tests: walking speed, timed up-and-go, six-minute walk, single-leg stance, timed chair stands, and flexibility test. The strength of five muscle groups was measured.
Participants with h-sarcopenia had lower weight, body mass index (BMI), fat mass, and absolute muscle strength (p ≤ .001); those with w-sarcopenia had higher weight, BMI, fat mass (p < .001), and low relative muscle strength (p ≤ .003). Participants with c-sarcopenia had poorer performance in all physical performance tests, whereas h-sarcopenia and w-sarcopenia were associated with poor performance in four tests.
Subjects with h- and w-sarcopenia differ significantly in terms of obesity indicators. Combining height- and weight-adjusted SMIs can be a feasible method to define sarcopenia.
Sijie Tan, Jianxiong Wang and Shanshan Liu
The purpose of this study was to establish the one-repetition maximum (1RM) prediction equations of a biceps curl, bench press, and squat from the submaximal skeletal muscle strength of 4–10RM or 11–15RM in older adults. The first group of 109 participants aged 60–75 years was recruited to measure their 1RM, 4–10RM, and 11–15RM of the three exercises. The 1RM prediction equations were developed by multiple regression analyses. A second group of participants with similar physical characteristics to the first group was used to evaluate the equations. The actual measured 1RM of the second group correlated significantly to the predicted 1RM obtained from the equations (r values were from .633–.985), and standard error of estimate ranged from 1.08–5.88. Therefore, the equations can be used to predict 1RM from submaximal skeletal muscle strength accurately for older adults.
Farnoosh Mafi, Soheil Biglari, Alireza Ghardashi Afousi and Abbas Ali Gaeini
Sarcopenia is defined as a loss of skeletal muscle mass, quality, and strength that occurs as a result of normal aging ( Rosenberg, 1997 ). The loss of skeletal muscle mass and strength caused by sarcopenia lowers people’s ability to do daily activities like standing up and walking and may weaken
Hellen C.G. Nabuco, Crisieli M. Tomeleri, Rodrigo R. Fernandes, Paulo Sugihara Junior, Edilaine F. Cavalcante, Danielle Venturini, Décio S. Barbosa, Analiza M. Silva, Luís B. Sardinha and Edilson S. Cyrino
kilograms divided by the square of the height in meters. Body Composition A spectral bioelectrical impedance device (Xitron Hydra; Xitron, San Diego, CA) was used to estimate the total body water, body fat (%), resistance ( R ), and reactance ( X c). The skeletal muscle mass (SMM) was estimated by the
Maria À. Cebrià i Iranzo, Mercè Balasch-Bernat, María Á. Tortosa-Chuliá and Sebastià Balasch-Parisi
even higher in Spain (37%) ( Salvà et al., 2016 ). The European Working Group on Sarcopenia in Older People (EWGSOP) defines this syndrome as a gradual and widespread loss of skeletal muscle mass and strength. As a result, mobility disorders appear, such as an increased risk of falls and fractures
Chantal A. Vella, Erin D. Michos, Dorothy D. Sears, Mary Cushman, Rachel B. Van Hollebeke, Michelle M. Wiest and Matthew A. Allison
, type 2 diabetes, functional disability, and premature death. 1 Skeletal muscle accounts for 40% of total body mass and is the main determinant of energy expenditure among sedentary individuals. Although regular physical activity is fundamental for preserving skeletal muscle mass, strength and function