Previous research has demonstrated that having adequate lower extremity and upper body muscle strength (generally defined as averting the lower tertile or quartile) reduces the risk of all-cause mortality 1 – 3 ; however, less overt is the importance of skeletal muscle strength on cancer
Scott J. Dankel, Jeremy P. Loenneke and Paul D. Loprinzi
Seong-won Han, Andrew Sawatsky, Azim Jinha and Walter Herzog
weakness is associated with increased peak pressures and decreased PFJ contact areas for precisely matched knee extensor forces. Methods Animals and Surgery Experiments were performed on skeletally mature New Zealand White rabbits (n = 6, 1 y old, 3.9 [0.5] kg; Covance Inc, Princeton, NJ). The rabbits were
Grant M. Tinsley and Brett S. Nickerson
skeletal muscle ( Pietrobelli et al., 1998 ), but are not of interest for traditional body composition monitoring. In addition, several investigations have indicated that the trunk region is most affected by recent food and fluid intake, and these effects are manifested as increased lean soft tissue (LST
Justin H. Rigby and Austin M. Hagan
.5978/islsm.13.95 10.5978/islsm.13.95 7. Leal Junior EC , Lopes-Martins RA , Dalan F , et al . Effect of 655-nm low-level laser therapy on exercise-induced skeletal muscle fatigue in humans . Photomed Laser Surg . 2008 ; 26 ( 5 ): 419 – 424 . PubMed ID: 18817474 doi:10.1089/pho.2007.2160 10
immunity ( Hagmar et al., 2008 ; Lancaster et al., 2005 ). Observational studies show that skeletal demineralization and hormonal imbalances are also prevalent among males, for example, male endurance athletes and athletes who strive for leanness ( Dolan et al., 2012 ; Guillaume et al., 2012 ; Hackney
Marc T. Hamilton, Enas Areiqat, Deborah G. Hamilton and Lionel Bey
Physical activity often declines with age because of a reduction in the spontaneous activities of daily living and because of less intense exercise. In controlled studies of young rats, it was shown that physical activities associated with walking and standing were especially important for maintaining a high level of lipoprotein lipase (LPL) activity in postural skeletal muscles (slowtwitch oxidative muscles). More intense contractions during run training were important for a high LPL activity in the fast-twitch glycolytic muscles. Aging also causes a fiber type–specific decrease of skeletal muscle LPL activity and LPL protein in weight-bearing skeletal muscles (and no aging effect in glycolytic muscles). Thus, contractile inactivity may be a significant factor causing sub-optimal triglyceride metabolism in skeletal muscles during both unloading in young animals and aging. Measurements of plasma LPL activity, plasma triglyceride (TG) clearance rates, postprandial hypertriglyceridemia after oral fat tolerance tests, and fasting TG levels were generally indicative of reduced plasma TG metabolism during middle or old age. In contrast, older endurance-trained individuals had a favorable blood lipid profile compared to age-matched or young controls, even when the controls were not overweight. Therefore, the poor TG metabolism that is frequently associated with aging may be caused by some of the same processes that lower skeletal muscle LPL activity of young sedentary individuals.
António J. Figueiredo, Manuel J. Coelho e Silva, Sean P. Cumming and Robert M. Malina
The purpose of the study was to compare the anthropometric, functional and sport-specific skill characteristics and goal orientations of male youth soccer players at the extremes of height and skeletal maturity in two competitive age groups, 11–12 and 13–14 years. The shortest and tallest players, and least and most skeletally mature players (n = 8 per group) within each age group were compared on chronological age; skeletal age (Fels method); pubertal status (pubic hair); size, proportions and adiposity; four functional capacities; four soccer-specific skills; and task and ego orientation. The tallest players were older chronologically, advanced in maturity (skeletal, pubertal) and heavier, and had relatively longer legs than the shortest players in each age group. At 11–12 years, the most mature players were chronologically younger but advanced in pubertal status, taller and heavier with more adiposity. At 13–14 years, the most mature players were taller, heavier and advanced in pubertal status but did not differ in chronological age compared with the least mature players. Players at the extremes of height and skeletal maturity differed in speed and power (tallest > shortest; most mature > lest mature), but did not differ consistently in aerobic endurance and in soccer-specific skills. Results suggested that size and strength discrepancies among youth players were not a major advantage or disadvantage to performance. By inference, coaches and sport administrators may need to provide opportunities for or perhaps protect smaller, skilled players during the adolescent years.
Breanne S. Baker, Kelsey J. Weitzel, Lisa A. Royse, Kristin Miller, Trent M. Guess, Stephen D. Ball and Dana L. Duren
The aging process, with and without the presence of chronic disease, is marked by a decline in the mass, quality, and overall function of skeletal muscle ( Fragala et al., 2019 ). Interventions aimed at increasing the physical fitness of older adults should address factors such as physical
Pedro Gómez-Carmona, Ismael Fernández-Cuevas, Manuel Sillero-Quintana, Javier Arnaiz-Lastras and Archit Navandar
thermography has been used as a valid, 7 accurate, 8 and reliable 7 , 9 technique to use on a daily basis to detect skeletal muscle overload and fatigue in athletes. 10 Infrared thermography, a noninvasive and fast technique, applied to the skin temperature provides a detailed temperature map of the human
Bettina Mittendorfer and Samuel Klein
Endurance exercise increases the use of endogenous fuels to provide energy for working muscles. Elderly subjects oxidize more glucose and less fat during moderate intensity exercise. This shift in substrate use is presumably caused by age-related changes in skeletal muscle, including decreased skeletal muscle respiratory capacity, because adipose tissue lipolysis and plasma fatty acid availability are not rate limiting. Endurance training in elderly subjects increases muscle respiratory capacity, decreases glucose production and oxidation, and increases fat oxidation thereby correcting or compensating for the alterations in substrate oxidation associated with aging.