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1.
Ann Geriatr Med Res ; 26(1): 4-15, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35038818

RESUMO

Muscle aging ultimately leads to the deterioration of human physiological functioning, including declining muscle strength, loss of muscle mass, and decreased quality of life in advanced age. Eccentric exercise is a key intervention that has the potential to ameliorate this problem. Recent studies have focused on evidence-based exercise interventions to prevent declines in muscle strength and physical function in older adults. This paper reviewed relevant literature on the use of eccentric exercise to improve muscle and mobility function in older adults. We explained not only the changes in mobility that occur with aging but also the rationale for and positive effects of eccentric intervention in older adults. We also explored several proposed mechanisms for the intramuscular changes caused by eccentric muscle contraction and considered the safety and side effects accompanying eccentric training. We concluded by suggesting that eccentric exercise is an exercise modality that can potentially improve muscle strength and enhance mobility in older adults.

2.
Aging Clin Exp Res ; 33(11): 3005-3014, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32020485

RESUMO

AIM: To examine the effects of a rural community-based program integrating health education and self-directed home-based resistance training on the mobility function of older women with knee osteoarthritis (OA). METHODS: Participants were assigned to the control (CON) or intervention (INT) group. Participants completed a mobility function assessment and questionnaire evaluation. The CON group received only the health education program and the INT group also participated in resistance training for 5 months. Primary outcomes were mobility function measured using a timed chair stand (TCS), timed up & go (TUG), gait speed (GS), and knee extensor strength (KES). We evaluated body composition and questionnaire results (WOMAC score, SARC-F scale, and SOF index) as secondary outcomes. RESULTS: There were significant differences in the interactions of group-by-time effects for TCS (p < 0.001), TUG (p = 0.006), GS (p = 0.020), and knee strength (p = 0.010). In the CON group, TCS (p = 0.003) and TUG (p = 0.005) increased compared with baseline, while in the INT group, TCS decreased significantly (p < 0.001) and TUG tended to decrease after the intervention. The INT group showed improvement in GS (p < 0.001) and KES (p = 0.003) after the intervention. By contrast, the CON group showed decreasing GS (p = 0.021) and KES (p = 0.011) compared with baseline. The SARC-F scale differed significantly in the interaction of group-by-time effects (p = 0.030), while the body composition, SOF index, and WOMAC score did not differ. CONCLUSION: These results suggest that an integrated intervention program combining self-directed home-based resistance training with health education effectively improves the mobility function of older adults with knee OA dwelling in rural areas.


Assuntos
Osteoartrite do Joelho , Idoso , Exercício Físico , Feminino , Educação em Saúde , Humanos , Articulação do Joelho , Osteoartrite do Joelho/terapia , População Rural
3.
Eur Geriatr Med ; 10(5): 747-752, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34652694

RESUMO

PURPOSE: This study compared manual stopwatch-based and automatic instrument-based measurements for gait speed (GS) obtained from the individual's usual walking pace using a 4-m walking test with different starting protocols in healthy older adults. METHODS: One hundred fifty-three healthy older adults aged ≥ 65 years (57 men, 96 women) participated. GS was measured using both a stopwatch and automatic timer with or without 2-m acceleration and deceleration phases. In the GS measurement using the stopwatch, the first tester stood in the middle of the timing zone (MS1) while the second walked beside the participants from the beginning line to the ending line (MS2). RESULTS: In the manual method, MS1 and MS2 showed similar GS for both standing and moving starts. There was no significant difference in GS measured between with the manual stopwatch and with the automatic timer in standing start. However, in the moving start protocol, GS measured with the manual stopwatch was significantly faster, by 0.05 m/s in MS1 (p < 0.001) and 0.04 m/s in MS2 (p < 0.001) compared to the timed GS with the automatic timer. GS measured manually using a moving start was significantly faster than that measured manually using a standing start (MS1, 0.06 m/s, 5.0%, p < 0.001; MS2, 0.08 m/s, 6.8%, p < 0.001); however, there was no difference between the start protocols when automatic measurements were performed (p = 0.135). CONCLUSIONS: The starting protocol (starting and moving start) affected the usual 4-m GS when measured using a manual stopwatch. Therefore, we suggest that careful evaluation to measure GS for functional assessment of older adults using the moving start with a manual stopwatch.

4.
5.
J Exerc Nutrition Biochem ; 22(2): 43-50, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30149426

RESUMO

PURPOSE: Declining muscle strength and function are hallmarks of the aging process. This study aimed to determine sex-related differences in myosin heavy chain (MHC) isoforms and muscle mass, strength, and quality with aging. METHODS: This cross-sectional study recruited 53 healthy participants (32 men, 21 women) aged 20-85 years who were divided into four groups: young men (n=17, YM, 29.23±4.51), older men (n=15, OM, 71.87±3.42), young women (n=11, YW, 29.64±4.88), and older women (n=10, OW, 68.1±1.91). Body composition and muscle strength and quality were analyzed. Muscle specimens were obtained from the vastus lateralis in all participants to analyze the type of MHC isoforms. RESULTS: Men showed a greater age-related decline in skeletal muscle mass (18.6%, p<0.01), lean body mass (10.1%, p<0.05), grip strength (35.3%, p<0.001), isometric strength (29.6%, p<0.001), isotonic power (42.5%, p<0.001), isokinetic strength (up to 44.3%, p<0.001), and muscle quality (up to 24.8%, p<0.01). In contrast, women had significantly lower isometric strength (24.2%, p<0.05), isotonic power (36.5%, p<0.01), and upper-body muscle quality (24.7%, p<0.001) with aging. In addition, the proportion of MHC IIa was significantly lower in OM (p<0.05) and OW (p<0.05) than in YM and YW, respectively. However, the proportion of MHC I was significantly higher in OM (p<0.01) than in YM but was high in both YW and OW. MHC I and MHC IIa negatively and positively correlated, respectively, with muscle strength and function. CONCLUSION: These results indicate the existence of sex-related differences in muscle mass, strength, and quality and MHC isoform composition with increasing age. The effects on muscle strength and function with aging were significant in men, but not in women. Higher and lower proportions of MHC I and MHC IIa fibers, respectively, were inversely associated with muscle strength and quality. In particular, Korean YW showed lower muscle strength and quality, and the proportion of MHC isoforms was similar to that in the muscles of OW.

6.
J Exerc Nutrition Biochem ; 21(3): 11-18, 2017 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-29036761

RESUMO

PURPOSE: To investigate the effects of conjugated linoleic acid (CLA)/n-3 supplements and resistance exercise training (RT) for 20 weeks on muscle quality and genes related to protein synthesis/degradation in middle-aged mice with high-fat diet (HFD)-induced obesity. METHODS: Nine-month-old C57BL/6 male mice were randomly assigned to five groups: 1) normal diet (C), 2) high-fat diet (H), 3) H+RT (HRT), 4) H+CLA/n-3 (H-CN), and 5) H+RT+CLA/n-3 (H-RTCN). HFD groups were given a diet containing 60% fat for 20 weeks, and exercised groups underwent progressive RT using weighted ladder climbing. The CLA/n-3 mixed diet contained 1% CLA and 1% n-3. Grip strength was assessed, and triceps were removed. RT-PCR was used to analyze transcript levels. RESULTS: Grip strength of the H group was significantly lower than that of the C group; however, those in the H-CN, H-RT, and H-RTN groups were significantly greater than that in the H group. However, the muscle quality was significantly greater only in the H-RT group compared with the H and H-CN groups. Akt expression decreased in the H-CN, H-RT, and H-RTCN groups compared with those in the C and H groups, whereas mammalian target of rapamycin expression increased in the H, H-CN, H-RT, and H-RTCN groups compared with that in the C group. However, atrogin1 was significantly downregulated in the H-RTCN group compared with that in the H and H-CN groups, and MuRF1 expression was also decreased in the H-RT and H-RTCN groups. Interestingly, atrogin1 and MuRF1 were downregulated in the H-RTCN group compared with that in the H-CN group. CONCLUSION: HFD-mediated gene expression involved in protein degradation was attenuated following 20-week RT with CLA/n-3. Furthermore, RT with or without CLA/n-3 improved grip strength and muscle quality in middle-aged mice during HFD. Therefore, RT with CLA/n-3 during HFD may improve muscle strength and quality by suppressing protein degradation.

7.
Geriatr Gerontol Int ; 17(5): 825-833, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27138245

RESUMO

AIM: In the present study, we determined the effect of an integrated health education and elastic band resistance training program on body composition, physical function, muscle strength and quality in community-dwelling elderly women. METHODS: We recruited participants with eligibility inclusion criteria, and randomly assigned them to either the control group (n = 19) or the intervention group (n = 19). The integrated intervention program comprised of health education and individual counseling, and elastic band training for 18 weeks (8 weeks of supervised training and 10 weeks of self-directed training). We assessed body composition, muscle strength and quality, and physical function at pre-, after 8 weeks (mid-) and 18 weeks (post-training). RESULTS: After the intervention, there were no significant changes in skeletal muscle index, fat free mass, total lean mass and total fat mass for both the control group and intervention group. However, the interaction effect was significantly different in SPPB score (P < 0.05), isokinetic strength (60 deg/s, P < 0.001; 120 deg/s; P < 0.05) and muscle quality (P < 0.05) after 18 weeks of intervention relative to the baseline of the control and intervention groups. The supervised elastic band training of 8 weeks did not improve short physical performance battery score and isokinetic strength, whereas there was a significant increase of those outcomes (10.6% improvement, 9.8~23.5% improvement) after 10 weeks of following self-directed exercise compared with the baseline. CONCLUSIONS: These results show the effectiveness of following self-directed resistance training with health education after supervised training cessation in improvement of short physical performance battery and leg muscle strength. This intervention program might be an effective method to promote muscle strength and quality, and to prevent frailty in elderly women. Geriatr Gerontol Int 2017; 17: 825-833.


Assuntos
Avaliação Geriátrica/métodos , Educação em Saúde/métodos , Envelhecimento Saudável/fisiologia , Vida Independente , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido/instrumentação , Idoso , Composição Corporal , Desenho de Equipamento , Exercício Físico/fisiologia , Feminino , Seguimentos , Felicidade , Humanos , Prognóstico , Fatores de Tempo
8.
Metabolism ; 65(5): 685-698, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27085776

RESUMO

PURPOSE: The appropriate mode of exercise training for cancer cachexia is not well-established. Using the colon-26 (C26) mouse model of cancer cachexia, we defined and compared the skeletal muscle responses to aerobic and resistance training. METHODS: Twelve-month old Balb/c mice were initially assigned to control, aerobic training (AT; wheel running), or resistance training (RT; ladder climbing) (n=16-17/group). After 8weeks of training, half of each group was injected with C26 tumor cells, followed by 3 additional weeks of training. Body composition and neuromuscular function was evaluated pre- and post-training. Muscles were collected post-training and analyzed for fiber cross-sectional area (CSA), Akt-mTOR signaling, and expression of insulin-like growth factor-I (IGF-I) and myogenic regulatory factors. RESULTS: Total body mass decreased (p<0.05) in C26 (-8%), AT+C26 (-18%), and RT+C26 (-15%) but not control. Sensorimotor function declined (p<0.05) in control (-16%), C26 (-13%), and RT+C26 (-23%) but not AT+C26. Similarly, strength/body weight decreased (p<0.05) in control (-7%), C26 (-21%), and RT+C26 (-10%) but not AT+C26. Gastrocnemius mass/body weight tended to be greater in AT+C26 vs. C26 (+6%, p=0.09). Enlargement of the spleen was partially corrected in AT+C26 (-27% vs. C26, p<0.05). Fiber CSA was lower in all C26 groups vs. control (-32% to 46%, p<0.05); however, the effect size calculated from C26 and AT+C26 was large (+24%, d=1.04). Phosphorylated levels of mTOR in AT+C26 exceeded C26 (+32%, p<0.05). RT+C26 showed greater mRNA expression (p<0.05) of IGF-IEa (+79%) and myogenin (+126%) with a strong tendency for greater IGF-IEb (+127%, p=0.069) vs. CONCLUSIONS: Aerobic or resistance training was unable to prevent tumor-induced body weight loss. However, aerobic training may have preserved function, reduced the inflammatory response of the spleen, and marginally rescued muscle mass possibly through activation of mTOR. Aerobic training may therefore have therapeutic value for patients with cancer cachexia. In contrast, resistance training induced the expression of genes associated with muscle damage and repair. This gene response may be supportive of excessive stress generated by high resistance loading in a tumor-bearing state.


Assuntos
Caquexia/prevenção & controle , Neoplasias do Colo/terapia , Modelos Animais de Doenças , Atividade Motora , Desenvolvimento Muscular , Músculo Esquelético/patologia , Treinamento Resistido , Animais , Caquexia/etiologia , Caquexia/fisiopatologia , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Neoplasias do Colo/fisiopatologia , Feminino , Regulação Neoplásica da Expressão Gênica , Camundongos Endogâmicos BALB C , Debilidade Muscular/etiologia , Debilidade Muscular/prevenção & controle , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiopatologia , Transplante de Neoplasias , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-akt/agonistas , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Distribuição Aleatória , Transdução de Sinais , Serina-Treonina Quinases TOR/química , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo
9.
J Exerc Nutrition Biochem ; 19(4): 281-8, 2015 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-27274460

RESUMO

PURPOSE: In the present study, we investigated the effects of 8 weeks of progressive resistance training on the level of skeletal muscle derived BDNF as well as glucose intolerance in Zucker diabetic rats. METHODS: Six week-old male Zucker diabetic fatty (ZDF) and Zucker lean control (ZLC) rats were randomly divided into 3 groups: sedentary ZLC (ZLC-Con), sedentary ZDF (ZDF-Con), and exercised ZDF (ZDF-Ex). Progressive resistance training using a ladder and tail weights was performed for 8 weeks (3 days/week). RESULTS: After 8 weeks of resistance training, substantial reduction in body weight was observed in ZDF-Ex compared to ZDF-Con. Though the skeletal muscle volume did not change, grip strength grip strength was significantly higher in ZDF-Ex compared to ZDF-Con. In the soleus, the level of BDNF was increased in ZDF-Con, but was significantly decreased (p<0.05) in ZDF-Ex, showing a training effect. Moreover, we found that there was a negative correlation (r=-0.657; p=0.004) between grip strength and BDNF level whereas there was a positive correlation (r=0.612; p=0.008) between plasma glucose level and BDNF level in skeletal muscle. CONCLUSION: Based upon our results, we demonstrated that resistance training inhibited the elevation of skeletal muscle derived-BDNF expression concomitant with the improvement of muscle strength in zucker diabetic rats. In addition, muscle-derived BDNF might be a potential mediator for the preventive effect of resistance training on the progress of type 2 diabetes.

10.
J. physiol. biochem ; 69(4): 697-705, dic. 2013.
Artigo em Inglês | IBECS | ID: ibc-121629

RESUMO

Autophagy, a highly conserved quality control mechanism, is essential for the maintenance of cellular homeostasis and for the orchestration of an efficient cellular response to stress. During aging, the efficiency of autophagic degradation declines, and intracellular waste products accumulate. Therefore, in this study, we tested the hypothesis that skeletal muscle from old mice would have decreased autophagosome formation when compared to the muscle from young mice. We also examined whether autophagic regulatory events differ between muscle fiber types and in response to exercise in aged male mice. The extensor digitorum longus (EDL) and gastrocnemius muscles were studied in young and old ICR mice. Exercise was performed by allowing the mice to run on a treadmill with a 5° incline at 16.4 m/min for 40 min/day, 5 days/week for 8 weeks after a 1-week adaptation period. Our results indicated that the levels of microtubule-associated protein 1b light chain 3, a marker of autophagosome formation, were lower in both the EDL and the gastrocnemius muscle of old mice compared to those young mice. To identify the factors related to the changes observed, the expression of autophagy regulatory proteins was examined in the EDL and gastrocnemius muscles. Beclin-1, autophagy-related gene 7 (ATG7), and lysosome-associated membrane protein were found to be lower in the EDL and gastrocnemius muscles of old mice compared to those in the young mice, then Beclin-1, ATG7, and muscle-specific RING finger protein-1 upregulated after regular exercise. Moreover, the muscle weight/body weight was significantly increased only in the gastrocnemius muscle of the old trained mice. These data suggest that autophagy regulatory events are attenuated in old skeletal muscle. However, this effect is upregulated when animals are subjected to exercise training (AU)


Assuntos
Animais , Ratos , Músculo Esquelético/fisiologia , Autofagia/fisiologia , Exercício Físico/fisiologia , Estresse Fisiológico/fisiologia , Envelhecimento/fisiologia
11.
Diabetes Metab J ; 37(5): 358-64, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24199165

RESUMO

BACKGROUND: Interleukin-15 (IL-15), a well-known myokine, is highly expressed in skeletal muscle and is involved in muscle-fat crosstalk. Recently, a role of skeletal muscle-derived IL-15 in the improvement of glucose homeostasis and insulin sensitivity has been proposed. However, little is known regarding the influence of endurance training on IL-15 expression in type 2 diabetic skeletal muscles. We investigated the effect of endurance exercise training on glucose tolerance and IL-15 expression in skeletal muscles using type 2 diabetic animal models. METHODS: MALE ZUCKER DIABETIC FATTY (ZDF) AND ZDF LEAN CONTROL (ZLC) RATS WERE RANDOMLY DIVIDED INTO THREE GROUPS: sedentary ZLC, sedentary ZDF (ZDF-Con), and exercised ZDF (ZDF-Ex). The ZDF-Ex rats were forced to run a motor-driven treadmill for 60 minutes once a day 5 times per week for 12 weeks. Intraperitoneal glucose tolerance test (IPGTT) was performed after 12 weeks. Expression of IL-15 was measured using ELISA in extracted soleus (SOL) and gastrocnemius medial muscles. RESULTS: After 12 weeks of treadmill training, reduction of body weight was observed in ZDF-Ex compared to ZDF-Con rats. Glucose tolerance using IPGTT in diabetic rats was significantly improved in ZDF-Ex rats. Furthermore, the expression of IL-15 was significantly increased (P<0.01) only in the SOL of ZDF-Ex rats compared to ZDF-Con. Additionally, IL-15 expression in SOL muscles was negatively correlated with change of body weight (R=-0.424, P=0.04). CONCLUSION: The present study results suggest that 12 weeks of progressive endurance training significantly improved glucose tolerance with concomitant increase of IL-15 expression in SOL muscles of type 2 diabetic rats.

12.
J Int Soc Sports Nutr ; 10(1): 21, 2013 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-23587302

RESUMO

BACKGROUND: In the present study, we determined the effects of HX108-CS (mixed extract of Schisandra chinensis and Chaenomeles sinensis) supplementation on lactate accumulation and endurance capacity. Furthermore, we examined CK (creatine kinase), LDH (lactate dehydrogenase) activity to determine whether the HX108-CS affected markers of skeletal muscle injury in vivo and in vitro. METHODS: Exercise capacity was measured by an exhaustive swimming test using ICR mice divided into four groups; one group received distilled water (DW) (Control group, n = 10), and the other groups received three different dosages of HX108-CS (10, 50 and 100 mg/kg, n = 10 per group) solution in water orally. Then, for the time-dependent measurements of blood lactate, CK, and LDH, Sprague-Dawley rats were divided into two groups; one received DW (Control group, n = 10), and the other group received HX108-CS (100 mg/kg, n = 10) solution in the same way as mice. Before the exercise test, the animals were given either DW or HX108-CS for 2 weeks. High-intensity treadmill exercise was performed for 30 minutes. Blood samples were collected and analyzed during and after exercise. For the in vitro experiment, C2C12 cells were treated with HX108-CS to examine its effect on lactate production, CK, and LDH activity. RESULTS: Blood lactate concentration was significantly lowered immediately after treadmill exercise in HX108-CS group; however, there were no significant differences in activities of CK and LDH between HX108-CS and control during treadmill exercise and recovery phase. Furthermore, treatment with 100 mg/kg of HX108-CS led to a significant increase in the time to exhaustion in swimming test, and concurrently blood lactate concentration was significantly decreased in 50 and 100 mg/kg treated group. Moreover, our results of in vitro experiment showed that HX108-CS suppressed lactate production, CK, and LDH activity in a dose-dependent manner. CONCLUSIONS: These results suggest that supplementation with HX108-CS may enhance exercise capacity by lowering lactate accumulation. This may in part be related to an amelioration of skeletal muscle injury.

13.
J Physiol Biochem ; 69(4): 697-705, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23471597

RESUMO

Autophagy, a highly conserved quality control mechanism, is essential for the maintenance of cellular homeostasis and for the orchestration of an efficient cellular response to stress. During aging, the efficiency of autophagic degradation declines, and intracellular waste products accumulate. Therefore, in this study, we tested the hypothesis that skeletal muscle from old mice would have decreased autophagosome formation when compared to the muscle from young mice. We also examined whether autophagic regulatory events differ between muscle fiber types and in response to exercise in aged male mice. The extensor digitorum longus (EDL) and gastrocnemius muscles were studied in young and old ICR mice. Exercise was performed by allowing the mice to run on a treadmill with a 5° incline at 16.4 m/min for 40 min/day, 5 days/week for 8 weeks after a 1-week adaptation period. Our results indicated that the levels of microtubule-associated protein 1b light chain 3, a marker of autophagosome formation, were lower in both the EDL and the gastrocnemius muscle of old mice compared to those young mice. To identify the factors related to the changes observed, the expression of autophagy regulatory proteins was examined in the EDL and gastrocnemius muscles. Beclin-1, autophagy-related gene 7 (ATG7), and lysosome-associated membrane protein were found to be lower in the EDL and gastrocnemius muscles of old mice compared to those in the young mice, then Beclin-1, ATG7, and muscle-specific RING finger protein-1 upregulated after regular exercise. Moreover, the muscle weight/body weight was significantly increased only in the gastrocnemius muscle of the old trained mice. These data suggest that autophagy regulatory events are attenuated in old skeletal muscle. However, this effect is upregulated when animals are subjected to exercise training.


Assuntos
Envelhecimento/metabolismo , Autofagia/genética , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/fisiologia , Envelhecimento/patologia , Animais , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteína 7 Relacionada à Autofagia , Proteína Beclina-1 , Biomarcadores/metabolismo , Peso Corporal , Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos ICR , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Músculo Esquelético/patologia , Tamanho do Órgão , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
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