It is generally accepted that free radicals or reactive oxygen species (ROS) play a primary role in the ageing process, especially in those tissues in which their generation is more pronounced, such as skeletal muscle (Fulle, et al. 2004). With aging a reduction in the cellular antioxidant buffering mechanisms (Hepple et al. 2003) and an increase in ROS generation due to mitochondrial dysfunction result in an increase in the oxidative stress to which cells are exposed (Barreiro et al., 2006). This results in damage to muscle components including myofibrilar proteins. Although the etiology of sarcopenia is still under investigation, reduced physical activity and oxidative stress have been found to play an important role (Jang et al. 2010; Argilés et al. 2015). Sarcopenia should then be fought through specific training designed to reduce the loss in muscle mass while minimizing ROS production. In this respect, exercise can induce antioxidant adaptation thereby balancing oxidative stress and damage in aging skeletal muscle (Ji, 2001, 2002). Hence the present study aimed at testing the hypothesis that an innovative medium-intensity (60% 1RM) resistive exercise program would be effective in increasing muscle mass and strength while minimizing ROS production and oxidative stress in older sarcopenic individuals. Methods: Twenty six older individuals (mean age 73.3±5.3 yr, n=14 ♂, n=12 ♀) were admitted to the training protocol consisting of 3 sessions per week for 12 weeks. Pre-training, all participants were diagnosed as sarcopenic on the basis of their skeletal muscle index (SMI, %) value obtained by bioelectrical impedance analysis (BIA). According to Janssen et al (2002), cut-off levels for normal SMI, class I, and class II sarcopenia were set as: men, greater than 37%, 37% to 31%, and less than 31%; women, greater than 28%, 28% to 22%, and less than 22%. Pre-training 19 (73%) individuals were classified as type I sarcopenic and 7 (27%) as type II sarcopenic. The training protocol included a 6-8 min warm-up on an aerobic ergometer (treadmill or bike, according to individual preference) followed by 3 series of 14-16 repetitions of chest press, vertical row, shoulder lateral raise and horizontal leg-press exercises performed at 60% 1RM, with a one-minute rest between series and muscle group. Muscle strength (1RM) and stair climbing power (Sartorio et al. 2001) were measured before and after training. Vastus lateralis (VL) muscle thickness and pennation angle were measured using B-mode ultrasound according to Narici et al. (1996). Blood and urine samples were collected before (PRE) and immediately after the end (POST) of training period. Total antioxidant capacity (TAC) and protein carbonyl (PC), thiobarbituric acid-reactive substances (TBARS), 8-isoprostane (8-iso PGF2α) and 8-OH-2-deoxyguanosine (8-OH-dG) were assessed by immuno-enzymatic assays. ROS production was determined by Electron Paramagnetic Resonance. Results: After the 12-wk training intervention, the prevalence of sarcopenia decreased by 20% with respect to pre-training, 4 were classified as type II sarcopenic, 17 as type I and five as non-sarcopenic. VL muscle thickness and pennation angle increased by 6% (P<0.001) and 12% (P<0.001) respectively after training. Consistent with these findings, muscle strength (1RM) increased by 86% (P<0.001) in the lower limbs (leg press) and on average by 95% (range 89-101%, P<0.001) in the upper limbs. Also, stair climbing power increased by 9.7% (P<0.004) after training. Before training, all oxidative stress biomarkers were significantly higher (P<0.001) and TAC values significantly lower (P<0.001) in the sarcopenic participants when compared to a population of healthy older controls (CTRLs) (n=15 ♂, n=12 ♀). After training, in the sarcopenic subjects a significant (P) reduction of blood ROS production rate (- 21%), PC (-27%), TBARS (-30%), 8-OH-dG.creatinine-1 (-38%), 8-iso PGF2α.creatinine-1 (-26%) was observed. At the same time, an increase of TAC (+25%), was found between PRE and POST. Conclusion: These novel findings show that a programme of medium-intensity (60% 1RM) resistance training is highly effective for decreasing oxidative stress, improving skeletal muscle morphology, size and function in older sarcopenic individuals. Furthermore, these results seem to rebut the previously reported differences in oxidative stress balance between older healthy controls and sarcopenic individuals.
Medium intensity resistive training for combating sarcopenia : effects on oxiative stress, muscle size, morphology, strength and power / A. Vezzoli, M. Montorsi, S. Mrakic-Sposta, S. Moretti, S. Porcelli, P. Vago, F. Cereda, S. Longo, M.V. Narici. - In: THE JOURNAL OF FRAILTY & AGING. - ISSN 2260-1341. - 5:S 1(2016 Jun), pp. P139.115-P139.116. ((Intervento presentato al convegno International conference of frailty and sarcopenia research tenutosi a Philadelphia (Pennsylvania) nel 2016.
|Titolo:||Medium intensity resistive training for combating sarcopenia : effects on oxiative stress, muscle size, morphology, strength and power|
VEZZOLI, ALESSANDRA (Primo)
LONGO, STEFANO (Penultimo)
|Parole Chiave:||elderly; training; hypertrophy|
|Settore Scientifico Disciplinare:||Settore M-EDF/02 - Metodi e Didattiche delle Attivita' Sportive|
Settore M-EDF/01 - Metodi e Didattiche delle Attivita' Motorie
|Data di pubblicazione:||giu-2016|
|Appare nelle tipologie:||01 - Articolo su periodico|
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