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1.
Redox Biol ; 53: 102341, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35623315

RESUMO

The role of mitochondrial ROS in signalling muscle adaptations to exercise training has not been explored in detail. We investigated the effect of supplementation with the mitochondria-targeted antioxidant MitoQ on a) the skeletal muscle mitochondrial and antioxidant gene transcriptional response to acute high-intensity exercise and b) skeletal muscle mitochondrial content and function following exercise training. In a randomised, double-blind, placebo-controlled, parallel design study, 23 untrained men (age: 44 ± 7 years, VO2peak: 39.6 ± 7.9 ml/kg/min) were randomised to receive either MitoQ (20 mg/d) or a placebo for 10 days before completing a bout of high-intensity interval exercise (cycle ergometer, 10 × 60 s at VO2peak workload with 75 s rest). Blood samples and vastus lateralis muscle biopsies were collected before exercise and immediately and 3 h after exercise. Participants then completed high-intensity interval training (HIIT; 3 sessions per week for 3 weeks) and another blood sample and muscle biopsy were collected. There was no effect of acute exercise or MitoQ on systemic (plasma protein carbonyls and reduced glutathione) or skeletal muscle (mtDNA damage and 4-HNE) oxidative stress biomarkers. Acute exercise-induced increases in skeletal muscle peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α) mRNA expression were augmented in the MitoQ group. Despite this, training-induced increases in skeletal muscle mitochondrial content were similar between groups. HIIT-induced increases in VO2peak and 20 km time trial performance were also similar between groups while training-induced increases in peak power achieved during the VO2peak test were augmented in the MitoQ group. These data suggest that training-induced increases in peak power are enhanced following MitoQ supplementation, which may be related to the augmentation of skeletal muscle PGC1α expression following acute exercise. However, these effects do not appear to be related to an effect of MitoQ supplementation on exercise-induced oxidative stress or training-induced mitochondrial biogenesis in skeletal muscle.


Assuntos
Antioxidantes , Exercício Físico , Compostos Organofosforados/farmacologia , Ubiquinona/análogos & derivados , Adulto , Antioxidantes/metabolismo , Suplementos Nutricionais , Exercício Físico/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Músculo Esquelético/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ubiquinona/farmacologia
2.
Appl Physiol Nutr Metab ; 47(7): 762-774, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35201920

RESUMO

Unaccustomed exercise causes muscle damage resulting in loss of muscle function, which may be attributable to exercise-induced increases in skeletal muscle reactive oxygen species. This study examined the effect of mitochondria-targeted antioxidant supplementation on recovery of muscle function following exercise. Thirty-two untrained men received MitoQ (20 mg/day) or a placebo for 14 days before performing  300 maximal eccentric contractions of the knee extensor muscles of 1 leg. Muscle function was assessed using isokinetic dynamometry before, immediately after, and 24, 48, 72, and 168 hours after exercise. Muscle soreness was assessed using a visual analogue scale 24, 48, 72, and 168 hours after exercise. Blood samples were collected before, immediately after, and 2, 24, 48, 72, and 168 hours after exercise and urine samples were collected before and during the 48 hours after exercise. The reduction in maximal voluntary isometric contraction force and peak concentric torque following exercise was unaffected by MitoQ while recovery of peak eccentric torque was delayed in the MitoQ group. Exercise-induced increases in urine F2-isoprostanes were unaffected by MitoQ. MitoQ augmented exercise-induced increases in plasma creatine kinase levels, while plasma IL-6 was similar between groups. Muscle soreness was not affected by MitoQ. These results indicate that MitoQ does not attenuate post-exercise muscle soreness and may delay recovery of muscle function following eccentric exercise. Trial registration number: ACTRN12620001089921. Novelty: Post-exercise recovery of maximal voluntary isometric contraction force and peak concentric torque were unaffected by MitoQ. MitoQ delayed post-exercise recovery of peak eccentric torque. Post-exercise muscle soreness was unaffected by MitoQ.


Assuntos
Contração Isométrica , Doenças Musculares , Antioxidantes/farmacologia , Creatina Quinase , Suplementos Nutricionais , F2-Isoprostanos , Humanos , Masculino , Mitocôndrias , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Mialgia/prevenção & controle , Torque
3.
J Int Soc Sports Nutr ; 18(1): 58, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34419082

RESUMO

BACKGROUND: Exercise increases skeletal muscle reactive oxygen species (ROS) production, which may contribute to the onset of muscular fatigue and impair athletic performance. Mitochondria-targeted antioxidants such as MitoQ, which contains a ubiquinone moiety and is targeted to mitochondria through the addition of a lipophilic triphenylphosphonium cation, are becoming popular amongst active individuals as they are designed to accumulate within mitochondria and may provide targeted protection against exercise-induced oxidative stress. However, the effect of MitoQ supplementation on cycling performance is currently unknown. Here, we investigate whether MitoQ supplementation can improve cycling performance measured as time to complete an 8 km time trial. METHOD: In a randomized, double-blind, placebo-controlled crossover study, 19 middle-aged (age: 44 ± 4 years) recreationally trained (VO2peak: 58.5 ± 6.2 ml·kg- 1·min- 1, distance cycled per week during 6 months prior to study enrollment: 158.3 ± 58.4 km) male cyclists completed 45 min cycling at 70% VO2peak followed by an 8 km time trial after 28 days of supplementation with MitoQ (20 mg·day- 1) and a placebo. Free F2-isoprostanes were measured in plasma samples collected at rest, after 45 min cycling at 70% VO2peak and after completion of the time trial. Respiratory gases and measures of rating of perceived exertion (RPE) were also collected. RESULTS: Mean completion time for the time trial was 1.3% faster with MitoQ (12.91 ± 0.94 min) compared to placebo (13.09 ± 0.95 min, p = 0.04, 95% CI [0.05, 2.64], d = 0.2). There was no difference in RPE during the time trial between conditions (p = 0.82) despite there being a 4.4% increase in average power output during the time trial following MitoQ supplementation compared to placebo (placebo; 270 ± 51 W, MitoQ; 280 ± 53 W, p = 0.04, 95% CI [0.49, 8.22], d = 0.2). Plasma F2-isoprostanes were lower on completion of the time trial following MitoQ supplementation (35.89 ± 13.6 pg·ml- 1) compared to placebo (44.7 ± 16.9 pg·ml- 1 p = 0.03). CONCLUSION: These data suggest that MitoQ supplementation may be an effective nutritional strategy to attenuate exercise-induced increases in oxidative damage to lipids and improve cycling performance.


Assuntos
Antioxidantes/farmacologia , Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Mitocôndrias Musculares/efeitos dos fármacos , Compostos Organofosforados/farmacologia , Substâncias para Melhoria do Desempenho/farmacologia , Ubiquinona/análogos & derivados , Adulto , Antioxidantes/metabolismo , Estudos Cross-Over , Método Duplo-Cego , F2-Isoprostanos/sangue , Humanos , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Compostos Organofosforados/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Consumo de Oxigênio , Substâncias para Melhoria do Desempenho/metabolismo , Esforço Físico/efeitos dos fármacos , Esforço Físico/fisiologia , Placebos/metabolismo , Placebos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Fenômenos Fisiológicos da Nutrição Esportiva/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva/fisiologia , Fatores de Tempo , Ubiquinona/metabolismo , Ubiquinona/farmacologia
5.
J Int Soc Sports Nutr ; 17(1): 25, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460873

RESUMO

BACKGROUND: Blackcurrants have come to be regarded as a superfood because of their high polyphenol content, namely anthocyanins. While many berry types have been studied, blackcurrant-anthocyanins may be the superior berry when it comes to athletic performance. The purpose of the review was to evaluate the effects of blackcurrant supplementation on athletic performance, oxidative markers, cognition, and side effects. METHODS: Systematic review and meta-analysis. Review manager software (version 5.3) was used for the meta-analysis. The risks of bias was independently assessed using the guidelines and criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. The data sources for the search included MEDLINE (Ovid), Google Scholar databases, additional references lists, conference proceedings and grey literature until August 2019. Eligibility Criteria included all blackcurrant (New Zealand derived) interventions, randomised control trials, human participants, placebo-controlled only. RESULTS: A total of 16 separate studies met the criteria for inclusion in the systematic review, with 9 studies contributing to this sport performance meta-analysis. There was an improvement in sport performance when supplementing with blackcurrant, 0.45 (95% CI 0.09-0.81, p = 0.01). The effective dose appears to be between 105 and 210 mg of total blackcurrant anthocyanins, prior to exercise. There were insufficient studies reporting oxidative markers, cognitive effects or biomarkers, and/or side effects to comment on the mechanism of action. CONCLUSION: Blackcurrant has a small, but significant, effect on sport performance, with no known detrimental side effects.


Assuntos
Antocianinas/administração & dosagem , Desempenho Atlético , Biomarcadores/sangue , Ribes , Humanos , Nova Zelândia , Ensaios Clínicos Controlados Aleatórios como Assunto , Fenômenos Fisiológicos da Nutrição Esportiva
6.
Intern Med J ; 46(11): 1284-1290, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27507731

RESUMO

BACKGROUND: Self-management programmes are an increasingly popular way of treating chronic diseases. AIMS: This study aims to determine the efficacy of the Stanford Chronic Disease Self-Management Programme (CDSMP) in a New Zealand context by assessing course outcomes and readability of the accompanying reference guide Living a Healthy Life with Chronic Conditions, 4th Edition. METHODS: This is a cross-sectional pre-post study conducted in Auckland between August 2009 and September 2015, using CDSMP participants' baseline and follow-up Health Education Intervention Questionnaire (heiQTM ) data. Readability of the guide was assessed using the Gunning Fog Index, Coleman Liau, Flesch Reading Ease, Flesch Kincaid Grade Level and Simplified Measure of Gobbledygook scores. RESULTS: Significant evidence of improvement (P ≤ 0.001) was observed in seven of the eight domains measured by the heiQTM (Deakin University, Centre for Population Health Research, Melbourne, Vic., Australia). The greatest improvements were seen in skill and technique acquisition (mean change score 0.25, P ≤ 0.001) and self-monitoring and insight (0.18, P ≤ 0.001). There was little evidence of improvement in health service navigation (0.04, P = 0.17). Readability analyses indicate that a person needs to be reading at a minimum of U.S. 8th grade level in order to understand the text, and possibly up to 11th grade. CONCLUSIONS: The CDSMP is effective for improving patient self-efficacy in the New Zealand setting. However, adaptation of the programme to support better health service navigation is warranted. The readability of the reference guide is not suitable for this setting and requires further improvement.


Assuntos
Doença Crônica/terapia , Compreensão , Gerenciamento Clínico , Letramento em Saúde/normas , Autocuidado , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Autoeficácia , Índice de Gravidade de Doença , Inquéritos e Questionários
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