scholarly journals Preserved Capacity for Adaptations in Strength and Muscle Regulatory Factors in Elderly in Response to Resistance Exercise Training and Deconditioning

2020 ◽  
Vol 9 (7) ◽  
pp. 2188 ◽  
Author(s):  
Andreas Mæchel Fritzen ◽  
Frank D. Thøgersen ◽  
Khaled Abdul Nasser Qadri ◽  
Thomas Krag ◽  
Marie-Louise Sveen ◽  
...  

Aging is related to an inevitable loss of muscle mass and strength. The mechanisms behind age-related loss of muscle tissue are not fully understood but may, among other things, be induced by age-related differences in myogenic regulatory factors. Resistance exercise training and deconditioning offers a model to investigate differences in myogenic regulatory factors that may be important for age-related loss of muscle mass and strength. Nine elderly (82 ± 7 years old) and nine young, healthy persons (22 ± 2 years old) participated in the study. Exercise consisted of six weeks of resistance training of the quadriceps muscle followed by eight weeks of deconditioning. Muscle biopsy samples before and after training and during the deconditioning period were analyzed for MyoD, myogenin, insulin-like growth-factor I receptor, activin receptor IIB, smad2, porin, and citrate synthase. Muscle strength improved with resistance training by 78% (95.0 ± 22.0 kg) in the elderly to a similar extent as in the young participants (83.5%; 178.2 ± 44.2 kg) and returned to baseline in both groups after eight weeks of deconditioning. No difference was seen in expression of muscle regulatory factors between elderly and young in response to exercise training and deconditioning. In conclusion, the capacity to gain muscle strength with resistance exercise training in elderly was not impaired, highlighting this as a potent tool to combat age-related loss of muscle function, possibly due to preserved regulation of myogenic factors in elderly compared with young muscle.

2011 ◽  
Vol 300 (3) ◽  
pp. R655-R662 ◽  
Author(s):  
Todd A. Trappe ◽  
Chad C. Carroll ◽  
Jared M. Dickinson ◽  
Jennifer K. LeMoine ◽  
Jacob M. Haus ◽  
...  

Evidence suggests that consumption of over-the-counter cyclooxygenase (COX) inhibitors may interfere with the positive effects that resistance exercise training has on reversing sarcopenia in older adults. This study examined the influence of acetaminophen or ibuprofen consumption on muscle mass and strength during 12 wk of knee extensor progressive resistance exercise training in older adults. Thirty-six individuals were randomly assigned to one of three groups and consumed the COX-inhibiting drugs in double-blind placebo-controlled fashion: placebo (67 ± 2 yr; n = 12), acetaminophen (64 ± 1 yr; n = 11; 4 g/day), and ibuprofen (64 ± 1 yr; n = 13; 1.2 g/day). Compliance with the resistance training program (100%) and drug consumption (via digital video observation, 94%), and resistance training intensity were similar ( P > 0.05) for all three groups. Drug consumption unexpectedly increased muscle volume (acetaminophen: 109 ± 14 cm3, 12.5%; ibuprofen: 84 ± 10 cm3, 10.9%) and muscle strength (acetaminophen: 19 ± 2 kg; ibuprofen: 19 ± 2 kg) to a greater extent ( P < 0.05) than placebo (muscle volume: 69 ± 12 cm3, 8.6%; muscle strength: 15 ± 2 kg), when controlling for initial muscle size and strength. Follow-up analysis of muscle biopsies taken from the vastus lateralis before and after training showed muscle protein content, muscle water content, and myosin heavy chain distribution were not influenced ( P > 0.05) by drug consumption. Similarly, muscle content of the two known enzymes potentially targeted by the drugs, COX-1 and -2, was not influenced ( P > 0.05) by drug consumption, although resistance training did result in a drug-independent increase in COX-1 (32 ± 8%; P < 0.05). Drug consumption did not influence the size of the nonresistance-trained hamstring muscles ( P > 0.05). Over-the-counter doses of acetaminophen or ibuprofen, when consumed in combination with resistance training, do not inhibit and appear to enhance muscle hypertrophy and strength gains in older adults. The present findings coupled with previous short-term exercise studies provide convincing evidence that the COX pathway(s) are involved in the regulation of muscle protein turnover and muscle mass in humans.


2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 529-529
Author(s):  
Amanda Randolph ◽  
Tatiana Moro ◽  
Adetutu Odejimi ◽  
Blake Rasmussen ◽  
Elena Volpi

Abstract Type 2 Diabetes Mellitus (T2DM) accelerates the incidence and increases the prevalence of sarcopenia in older adults. This suggests an urgent need for identifying effective sarcopenia treatments for older adults with T2DM. It is unknown whether traditional approaches, such as progressive resistance exercise training (PRET), can effectively counteract sarcopenia in older patients with T2DM. To test the efficacy of PRET for the treatment of sarcopenia in older adults with T2DM, 30 subjects (15 T2DM and 15 age- and sex- matched controls) underwent metabolic testing with muscle biopsies before and after a 13-week full-body PRET program. Primary outcome measures included changes in appendicular lean mass, muscle strength, and mixed muscle fractional synthesis rate (FSR). Before PRET, BMI-adjusted appendicular lean mass was significantly lower in the T2DM group (0.7095±0.0381 versus 0.8151±0.0439, p&lt;0.0001). As a result of PRET, appendicular lean mass adjusted for BMI and muscle strength increased significantly in both groups, but to a lesser extent for the T2DM group (p=0.0009) . Preliminary results for FSR (n=25) indicate that subjects with T2DM had lower basal FSR prior to PRET (p=0.0197) . Basal FSR increased significantly in the control group after PRET (p=0.0196), while it did not change in the T2DM group (p=0.3537). These results suggest that in older adults the positive effect of PRET on muscle anabolism and strength is reduced by T2DM . Thus, older adults with T2DM may require more intensive, multimodal and targeted sarcopenia treatment. Funded by NIH R01AG049611 and P30AG024832.


2017 ◽  
Vol 99 ◽  
pp. 98-109 ◽  
Author(s):  
Michael J. Stec ◽  
Anna Thalacker-Mercer ◽  
David L. Mayhew ◽  
Neil A. Kelly ◽  
S. Craig Tuggle ◽  
...  

2018 ◽  
Vol 124 (4) ◽  
pp. 888-898 ◽  
Author(s):  
Neil A. Kelly ◽  
Kelley G. Hammond ◽  
C. Scott Bickel ◽  
Samuel T. Windham ◽  
S. Craig Tuggle ◽  
...  

Aging muscle atrophy is in part a neurodegenerative process revealed by denervation/reinnervation events leading to motor unit remodeling (i.e., myofiber type grouping). However, this process and its physiological relevance are poorly understood, as is the wide-ranging heterogeneity among aging humans. Here, we attempted to address 1) the relation between myofiber type grouping and molecular regulators of neuromuscular junction (NMJ) stability; 2) the impact of motor unit remodeling on recruitment during submaximal contractions; 3) the prevalence and impact of motor unit remodeling in Parkinson’s disease (PD), an age-related neurodegenerative disease; and 4) the influence of resistance exercise training (RT) on regulators of motor unit remodeling. We compared type I myofiber grouping, molecular regulators of NMJ stability, and the relative motor unit activation (MUA) requirement during a submaximal sit-to-stand task among untrained but otherwise healthy young (YA; 26 yr, n = 27) and older (OA; 66 yr, n = 91) adults and OA with PD (PD; 67 yr, n = 19). We tested the effects of RT on these outcomes in OA and PD. PD displayed more motor unit remodeling, alterations in NMJ stability regulation, and a higher relative MUA requirement than OA, suggesting PD-specific effects. The molecular and physiological outcomes tracked with the severity of type I myofiber grouping. Together these findings suggest that age-related motor unit remodeling, manifested by type I myofiber grouping, 1) reduces MUA efficiency to meet submaximal contraction demand, 2) is associated with disruptions in NMJ stability, 3) is further impacted by PD, and 4) may be improved by RT in severe cases. NEW & NOTEWORTHY Because the physiological consequences of varying amounts of myofiber type grouping are unknown, the current study aims to characterize the molecular and physiological correlates of motor unit remodeling. Furthermore, because exercise training has demonstrated neuromuscular benefits in aged humans and improved innervation status and neuromuscular junction integrity in animals, we provide an exploratory analysis of the effects of high-intensity resistance training on markers of neuromuscular degeneration in both Parkinson’s disease (PD) and age-matched older adults.


1998 ◽  
Vol 84 (2) ◽  
pp. 459-464 ◽  
Author(s):  
Kim C. Westerlind ◽  
James D. Fluckey ◽  
Scott E. Gordon ◽  
William J. Kraemer ◽  
Peter A. Farrell ◽  
...  

Westerlind, Kim C., James D. Fluckey, Scott E. Gordon, William J. Kraemer, Peter A. Farrell, and Russell T. Turner.Effect of resistance exercise training on cortical and cancellous bone in mature male rats. J. Appl. Physiol. 84(2): 459–464, 1998.—The effect of resistance training on tibial cancellous and cortical bone was evaluated in rats by using static histomorphometry and Northern analysis. Five-month-old male Sprague-Dawley rats were randomly assigned to exercise (Ex; n = 8) or control (Con; n = 4) groups. Animals were operantly conditioned to press two levers, facilitating full extension and flexion of the hindlimbs (“squats”), while wearing an unweighted vest. After an 8-wk familiarization period, Ex animals performed 3 sessions/wk for 17–19 sessions with progressively increased amounts of weight applied to the vest. Con rats completed the same exercise protocol without applied resistance. No difference in cross-sectional, medullary, or cortical bone area was observed between Ex and Con rats in the tibial diaphysis. In contrast, the cancellous bone area in the proximal tibial metaphysis was significantly larger in trained rats. Trabecular number, trabecular thickness, and the percentage of cancellous bone covered by osteoid were significantly greater in the Ex animals compared with Con animals. In addition, steady-state mRNA levels for osteocalcin for the Ex group were 456% those expressed in the Con group. The data demonstrate that resistance training increases cancellous bone area in sexually mature male rats and suggest that it does so, in part, by stimulating bone formation.


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