Effects of aging and resistance exercise on determinants of muscle strength

Abstract

Although the loss of muscle strength with aging is multifactorial, the primary factor is the loss of muscle mass. A preferential loss of Type II (fast-twitch) muscle fibers which produce more force than Type I fibers is also observed. The loss of muscle mass may be related to a reduction in the rate of muscle protein synthesis in the old versus the young. Changes in muscle quality and the ability to activate muscle appear to play a minor role in the loss of strength with age. However, co-activation of antagonist muscle groups does appear to reduce muscle force generating capacity in the elderly. Strength gains in response to resistance exercise training in the elderly, although substantial, may be less than in young individuals. Increases in muscle mass appear to be similar in elderly and young individuals as does the muscle protein synthetic response to resistance exercise. Muscle co-activation appears to be substantially and similarly reduced (improved) in young and elderly individuals as a result of resistance training.

Responses to Maximal Strength Training in Different Age and Gender Groups

“…Muscle strength is important for everyday functionality in all age groups. From the age of approximately 40, maximal muscle strength decreases steadily ( Lindle et al, 1997 ; Lambert and Evans, 2002 ; Petrella et al, 2005 ; Distefano and Goodpaster, 2018 ), and the decrease seems to accelerate from the age of 50 to 70 ( Unhjem et al, 2016 ). As a consequence of this, elevated risk of physical frailty, reduction in general motor function, decline in functional movement, poor balance, falls, risk of fracture, and decline in quality of life has been reported ( Fiatarone et al, 1994 ; Kirkendall and Garrett, 1998 ; Kanegusuku et al, 2015 ; Unhjem et al, 2016 ).…”

Ultrasonic Echo Intensity as a New Noninvasive In Vivo Biomarker of Frailty

“…Aging involves changes in the quality and quantity of muscle, including an increase in the amount of connective and adipose tissue, a decrease in the number and size of muscle fibers, a decrease in maximum voluntary agonist activity, and an increase in the alpha antagonist . These physiological factors in older adults result in loss of strength and the functional capacity of the muscle, which is one of the most‐important features of frailty …”

“…A ging involves changes in the quality and quantity of muscle, including an increase in the amount of connective and adipose tissue, a decrease in the number and size of muscle fibers, a decrease in maximum voluntary agonist activity, and an increase in the alpha antagonist. 1,2 These physiological factors in older adults result in loss of strength and the functional capacity of the muscle, which is one of the most-important features of frailty. 3 The quality and quantity of skeletal muscle can be easily assessed using ultrasound, 4,5 which can identify structural changes in muscle caused by degeneration, which increases echogenicity, 6 or echo intensity (EI).…”

Gambaran Kekuatan Otot Pada Lansia Di Bplu Senja Cerah Paniki Bawah

“…Faktor penyebab yang utama yaitu penurunan massa otot. 4 Penurunan kekuatan otot ini dimulai pada umur 40 tahun dan prosesnya akan semakin cepat pada usia setelah usia 75 tahun.…”