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1.
Sports Health ; 12(1): 74-79, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31642726

RESUMO

BACKGROUND: Lower extremity overuse injuries are common among runners, especially first-time marathoners. Hip abductor and quadriceps strengthening is often recommended to reduce running-related injuries. HYPOTHESIS: A 12-week strength training program would decrease the rate of overuse injuries resulting in marathon noncompletion and improve race finishing time. STUDY DESIGN: Randomized trial. LEVEL OF EVIDENCE: Level 2. METHODS: Twelve weeks before the New York City Marathon, first-time marathon runners age 18 years and older were randomized into a strength training group or an observation group. The strength training group was instructed to perform a 10-minute program 3 times weekly using written and video instruction. This program targeted the quadriceps, hip abductor, and core muscle groups. Injuries were self-reported through biweekly surveys, with major injuries being those that resulted in marathon noncompletion and minor injuries being those that impaired training or race performance. RESULTS: A total of 720 runners were enrolled (mean age, 35.9 ± 9.4 years; 69.4% female), of whom 583 runners started the marathon and 579 completed it. The incidence of major injury was 8.9% and minor injury was 48.5%. Fifty two of 64 major injuries were overuse, of which 20 were bone stress injuries. The incidence of overuse injury resulting in marathon noncompletion was 7.1% in the strength training group and 7.3% in the observation group (risk ratio, 0.97; 95% CI, 0.57-1.63; P = 0.90). The mean finishing time was 5 hours 1 ± 60 minutes in the strength training group and 4 hours 58 ± 55 minutes in the observation group (P = 0.35). CONCLUSION: There is a high prevalence of injury among first-time marathon runners, but this self-directed strength training program did not decrease overuse injury incidence resulting in marathon noncompletion. CLINICAL RELEVANCE: Prevention strategies such as strength training need to be developed and evaluated through clinical trials to reduce the high prevalence of overuse injuries in runners, especially for high-risk populations such as first-time marathon runners.


Assuntos
Transtornos Traumáticos Cumulativos/prevenção & controle , Extremidade Inferior/lesões , Força Muscular/fisiologia , Resistência Física/fisiologia , Treinamento de Resistência , Corrida/lesões , Adulto , Transtornos Traumáticos Cumulativos/epidemiologia , Transtornos Traumáticos Cumulativos/fisiopatologia , Humanos , Cidade de Nova Iorque/epidemiologia , Fatores de Risco , Corrida/fisiologia
2.
An Acad Bras Cienc ; 91(4): e20180957, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800698

RESUMO

The mechanism behind exercise-induced fatigue is a significant topic in the field of sports physiology. Therefore, establishing and evaluating an acute exercise-induced fatigue animal model that explores the limits of the motor system may provide greater insight into these mechanisms. Heart rate is an important quantitative parameter that accurately reflects the immediate change in physical function due to exercise load. And there is likely to be an important correlation between heart rate and behavioral performance. In this study, changes in heart rate and behavioral indexes during exercise-induced fatigue were quantitatively analyzed in rats using heart rate telemetry and video methods respectively. The behavioral indexes were used as independent variables and the degree of fatigue was used as the forecast value. Ternary quadratic function curve fitting was used to deduce a formula to calculate a fatigue score: Y = 15.2548+0.4346∙xa-0.1154∙xb+0.6826∙xc+0.0044∙xa∙xb-0.0021∙xb∙xc-0.0013∙xc∙xa-0.0023∙xa2-0.0016∙xb2 (r2=0.906). It identified a linear relationship between heart rate and exercise intensity, with a plateau in heart rate occurring during difference periods. It will serve as an effective reference for the modeling of exercise-induced fatigue. In addition, it also provides a theoretical method for analyzing the correlation between peripheral and central parameters.


Assuntos
Teste de Esforço , Fadiga , Condicionamento Físico Animal/fisiologia , Resistência Física/fisiologia , Animais , Masculino , Modelos Animais , Ratos , Ratos Wistar , Fatores de Tempo
4.
Adv Neurobiol ; 23: 331-346, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31667814

RESUMO

Brain glycogen stored in astrocytes produces lactate as a neuronal energy source transported by monocarboxylate transporters (MCTs) to maintain neuronal functions, such as hippocampus-regulated memory formation. Although exercise activates brain neurons, the role of astrocytic glycogen in the brain during exercise remains unknown. Since muscle glycogen fuels active muscles during exercise, we hypothesized that astrocytic glycogen plays an energetic role in the brain during exercise to maintain endurance capacity through lactate transport. To explore this hypothesis, we have used a rat model of prolonged exercise, microwave irradiation for the accurate detection of brain glycogen, capillary electrophoresis-mass spectrometry-based metabolomics, and inhibitors of glycogenolysis (1,4-dideoxy-1,4-imino-D-arabinitol; DAB) and lactate transport (α-cyano-4-hydroxycinnamate; 4-CIN). During prolonged exhaustive exercise, muscle glycogen was depleted and brain glycogen decreased when associated with decreased blood glucose levels and increased serotonergic activity known as central fatigue factors, suggesting brain glycogen decrease as an integrative factor for central fatigue. Prolonged exhaustive exercise also increased MCT2 protein in the brain, which takes up lactate in neurons, just as muscle MCTs are increased. Metabolomics revealed that brain but not muscle adenosine triphosphate (ATP) was maintained with lactate and other glycogenolytic and glycolytic sources. Intracerebroventricular (icv) injection of DAB suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An icv injection of 4-CIN also decreased hippocampal ATP, resulting in lower endurance capacity. Our findings provide direct evidence that astrocytic glycogen-derived lactate fuels the brain to maintain endurance capacity during exhaustive exercise. Brain ATP levels maintained by glycogen might serve as a possible defense mechanism for neurons in the exhausted state.


Assuntos
Astrócitos/metabolismo , Encéfalo/metabolismo , Fadiga/metabolismo , Glicogênio/metabolismo , Resistência Física/fisiologia , Trifosfato de Adenosina/metabolismo , Animais , Encéfalo/citologia , Glicogenólise , Hipocampo/citologia , Hipocampo/metabolismo , Ácido Láctico/metabolismo , Metabolômica , Neurônios/metabolismo , Ratos
5.
J Int Soc Sports Nutr ; 16(1): 50, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699159

RESUMO

Background In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~ 60% of energy intake, 5-8 g·kg- 1·d- 1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~ 1.6 g·kg- 1·d- 1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g.kg- 1·d- 1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150-400 Kcal·h- 1 (carbohydrate, 30-50 g·h- 1; protein, 5-10 g·h- 1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450-750 mL·h- 1 (~ 150-250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., > 575 mg·L- 1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety.


Assuntos
Carboidratos da Dieta/administração & dosagem , Ingestão de Energia , Necessidades Nutricionais , Corrida/fisiologia , Fenômenos Fisiológicos da Nutrição Esportiva , Atletas , Desempenho Atlético , Comportamento Competitivo , Proteínas na Dieta/administração & dosagem , Humanos , Resistência Física , Corrida/classificação , Sociedades
6.
Zhongguo Ying Yong Sheng Li Xue Za Zhi ; 35(4): 339-345, 2019 Jul 28.
Artigo em Chinês | MEDLINE | ID: mdl-31701719

RESUMO

OBJECTIVE: To understand and analyze the rules of endurance exercise on the cerebral cortex adaptive mechanism in aged rats. METHODS: In this study, 3-month-old (n=20), 13-month-old (n=24) and 23-month-old (n=24) specific-pathogen free (SPF) male Sprague-Dawley Rat (SD) rats were divided into young (Y-SED), middle-aged (M-SED) and old-aged (O-SED) sedentary control group, and the corresponding Y-EX, M-EX and O-EX in the endurance exercise runner group. The 10-weeks of regular moderate-intensity aerobic exercise intervention were carried out in the endurance exercise runner group. The exercise mode is treadmill exercise (slope 0), and the exercise intensity gradually increases from 60%~65% of the maximum oxygen consumption (V·O2max) to 70%~75%, and the exercise time is 10 weeks. Hematoxylin and eosin (HE) staining was used to detect age-related morphological changes. The expressions of superoxide dismutase(SOD) and brain-derived neurotrophic factor (BDNF) and the expressions of synapsin 1 (SYN1) and Ca2+/calmodulin- dependent protein kinases IIα (CaMK IIα) / AMP-activated protein kinase α1(AMPKα1) / mammalian target of rapamycin (mTOR) pathway -related genes were detected. RESULTS: The cerebral cortex structure of the rats in each group showed age-related aging changes, the expression of SOD in the cortex showed a gradual decline, the expression of BDNF showed an age-increasing trend, and the expression levels of SYN1 and CaMK IIα were increased with age. The changes in AMPKα1 and SirT2 and IP3R, AKT1 and mTOR mRNA levels were increased slightly in middle-aged rats and decreased in aged rats. Compared with the rats in each sedentary control group, the nucleus of the cerebral cortex was tightly arranged and the number of nuclei observed under the microscope was increased significantly in each exercise group. Exercise promoted the expressions of SOD, BDNF and synaptophysin SYN1 in the cortex of rats, and the expression levels of SOD and BDNF in aged rats were up-regulated significantly (P< 0.01). The expression level of SYN1 in rats was up-regulated significantly (P<0.05) in the young and aged rats. The expression of CaMK IIα in the cortex of middle-aged and aged rats was up-regulated (P<0.01), while the expression level of CaMK IIα in young rats was down-regulated (P<0.01). Exercise could up-regulate the expression level of AMPKα1 in the cortex of young rats (P< 0.05), but not in middle-aged and old-age rats. Exercise could up-regulate the expression of SirT2 in the cortex of rats in all age groups (P<0.05). Exercise up-regulated the expression of phosphoinositide 3-kinase (IP3R)/ protein kinase B 1(AKT1) /mTOR in the cortex of rats, among which young IP3R was significantly up-regulated (P<0.01) in the young group, mTOR was significantly up-regulated in young and middle-aged group (P<0.01), and mTOR was also significantly up-regulated in the aged group (P<0.05). CONCLUSION: Endurance exercise up-regulates BDNF expression, regulates CaMKIIα signaling, activates AMPK signaling pathway and IP3R / AKT1 / mTOR signaling pathway, and improves synaptic plasticity in the cortex.


Assuntos
Córtex Cerebral/fisiologia , Plasticidade Neuronal , Condicionamento Físico Animal , Resistência Física , Transdução de Sinais , Fatores Etários , Animais , Masculino , Ratos , Ratos Sprague-Dawley
7.
J Sports Med Phys Fitness ; 59(10): 1709-1715, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31694363

RESUMO

BACKGROUND: The purpose of this study was to investigate the effects of an Ironman-distance triathlon on bone metabolism. METHODS: Nine recreational male triathletes (39.7±8.2 years old) were voluntarily recruited before a 226-km Ironman triathlon race. Baseline blood samples were collected >1 hour before race. Serial post-race blood sampling time points included immediately (0hr), 1 hour (1hr), 1 day (d), 3 d, and 5 d after the Ironman race. RESULTS: Serum muscle damage markers, serum myoglobin, creatine kinase (CK) and lactate dehydrogenase (LDH) revealed significant post-race peak values immediately, 1hr and 1d after the race, respectively. Except for the marginally higher serum CK and myoglobin at 5d (P=0.01~0.05), all post-race serum levels of muscle damage markers were significantly higher than baseline levels (P<0.01). Serum phosphorus values were significantly higher immediately (0hr) after the Ironman race. Serum osteocalcin, an index specific to bone formation, showed a significant decrease at time points 0hr and 1hr, but a significant increase 1 day after (P<0.01) and a marginal increase 3 and 5 days after (P=0.01~0.05) the race. No difference was shown in type I collagen C-telopeptide (CTX-1), a bone resorption marker. Pearson's correlation between serum osteocalcin and CTX-1 was done at each time point, and significant correlation was shown on the 5th d after the race (r=0.591, P<0.05). CONCLUSIONS: An Ironman-distance contest induces a bone-formative-favoring turnover during the post-race period for amateur male triathletes.


Assuntos
Desempenho Atlético , Osso e Ossos/metabolismo , Adulto , Atletas , Ciclismo/fisiologia , Biomarcadores/análise , Creatina Quinase/sangue , Humanos , L-Lactato Desidrogenase/sangue , Masculino , Pessoa de Meia-Idade , Mioglobina/sangue , Resistência Física/fisiologia , Corrida/fisiologia , Natação/fisiologia
8.
Ther Umsch ; 76(6): 323-327, 2019 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-31762415

RESUMO

Pulmonary Rehabilitation Abstract. Pulmonary rehabilitation is a comprehensive therapeutic approach for patients with advanced chronic lung diseases which leads to a decline of dyspnea, an increase of exercise capacity and an increase of quality of life. Further effects are a reduction of frequency of hospitalisations and an increase of physical activity, if a self management education program is integrated. Pulmonary rehabilitation incorporates an individualised training program with focus on endurance, strength and mobility, further a disease specific education with the goal to improve self efficacy and self management of the patients, specially with the goal to improve their daily physical activity. Due to the good evidence of pulmonary rehabilitation, the accredited programs are accepted and paid by the swiss insurances.


Assuntos
Terapia por Exercício , Pneumopatias , Doença Pulmonar Obstrutiva Crônica , Dispneia/etiologia , Dispneia/prevenção & controle , Exercício , Humanos , Pneumopatias/reabilitação , Resistência Física , Doença Pulmonar Obstrutiva Crônica/reabilitação , Qualidade de Vida , Resultado do Tratamento
9.
J Int Soc Sports Nutr ; 16(1): 47, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31660991

RESUMO

BACKGROUND: TeaCrine® is the synthetic version to naturally occurring theacrine (1, 3, 7, 9-tetramethyluric acid) found in the leaves of Camellia kucha tea plants. A few studies have examined the effects of TeaCrine® on cognitive perception, but no research exists examining its effects on resistance exercise performance. The purpose of this study was to determine the efficacy of TeaCrine®, a caffeine-like compound, on maximal muscular strength, endurance, and power performance in resistance-trained men. METHODS: Twelve resistance-trained men participated in a randomized, double-blind, cross-over designed study. Each participant performed one-repetition maximum (1RM) bench press, 1RM squat, bench press repetitions to failure (RTF) at 70% 1RM, squat RTF at 70% 1RM, and 2-km rowing time trial 90 min after consumption of: (1) Caffeine 300 mg (CAFF300); (2) TeaCrine® 300 mg (TEA300); (3) TeaCrine® + Caffeine (COMBO; 150 mg/150 mg); (4) Placebo 300 mg (PLA). Power and velocity were measured using a TENDO Power Analyzer. Visual analogue scales for energy, focus, motivation to exercise, and fatigue were administered at baseline and 90 min post-treatment ingestion (pre-workout). Rating of perceived exertion was assessed after bench press RTF and squat RTF. RESULTS: There were no differences between groups for 1RM, RTF, and power in the bench press and squat exercises. Only CAFF300 resulted in significant increases in perceived energy and motivation to exercise vs. TEA300 and PLA (Energy: + 9.8%, 95% confidence interval [3.3-16.4%], p < 0.01; + 15.3%, 95% CI [2.2-28.5%], p < 0.02; Motivation to exercise: + 8.9%, 95% CI [0.2-17.6%], p = 0.04, + 14.8%, 95% CI [4.7-24.8%], p < 0.01, respectively) and increased focus (+ 9.6%, 95% CI [2.1-17.1%], p = 0.01) vs. TEA300, but there were no significant differences between CAFF300 and COMBO (Energy + 3.9% [- 6.9-14.7%], Focus + 2.5% [- 6.3-11.3%], Motivation to exercise + 0.5% [- 11.6-12.6%]; p > 0.05). CONCLUSION: Neither TEA300, CAFF300, COMBO, or PLA (when consumed 90 min pre-exercise) improved muscular strength, power, or endurance performance in resistance-trained men. Only CAFF300 improved measures of focus, energy, and motivation to exercise.


Assuntos
Cafeína/farmacologia , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/farmacologia , Resistência Física/efeitos dos fármacos , Ácido Úrico/análogos & derivados , Adulto , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Treinamento de Resistência , Ácido Úrico/farmacologia , Adulto Jovem
10.
Clin Interv Aging ; 14: 1681-1691, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31631989

RESUMO

Grip strength has been proposed as a biomarker. Supporting this proposition, evidence is provided herein that shows grip strength is largely consistent as an explanator of concurrent overall strength, upper limb function, bone mineral density, fractures, falls, malnutrition, cognitive impairment, depression, sleep problems, diabetes, multimorbidity, and quality of life. Evidence is also provided for a predictive link between grip strength and all-cause and disease-specific mortality, future function, bone mineral density, fractures, cognition and depression, and problems associated with hospitalization. Consequently, the routine use of grip strength can be recommended as a stand-alone measurement or as a component of a small battery of measurements for identifying older adults at risk of poor health status.


Assuntos
Depressão/psicologia , Força da Mão/fisiologia , Nível de Saúde , Resistência Física/fisiologia , Qualidade de Vida/psicologia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Depressão/epidemiologia , Feminino , Avaliação Geriátrica , Hospitalização , Humanos , Masculino , Multimorbidade
11.
Medicine (Baltimore) ; 98(38): e17290, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31568013

RESUMO

BACKGROUND: Previous studies have reported that self-selection of the training intensity can be an interesting strategy to improve adherence in aerobic exercise programs. However, its effectiveness with weight training has not been systematically reviewed and remains unclear. In this study, we will describe a systematic review protocol that aims to investigate if people are able to self-select an intensity during weight training sufficient to enhance muscular strength. METHODS: This protocol is guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. In this study, we will search the following electronic databases: PubMed, Science Direct, Scopus, Web of Science and SPORTDiscus. Intervention studies with at least one weight training session performed at self-selected intensity, with people from both genders and all age ranges will be included. The Downs & Black checklist will be used for methodological quality assessment. Two experienced reviewers will independently perform the selection of studies, data extraction, and evaluation of the methodological quality. CONCLUSION: This will be the first systematic review describing the results of weight training intervention studies with self-selected intensity. This study will provide high-quality and reliable evidence for health professionals and may direct methodological recommendations for further studies. PROSPERO REGISTRATION NUMBER: CRD42019120323.


Assuntos
Treinamento de Resistência/métodos , Autocuidado , Humanos , Força Muscular , Resistência Física , Autocuidado/psicologia
12.
Int J Sports Med ; 40(13): 856-862, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31505701

RESUMO

Several studies report neurological complications such as brain injury induced by ischemia or edema following exhaustive endurance sport. We aimed to detect the frequency of acute brain lesions after a marathon race. In the prospective observational Berlin Beat of Running study, 110 experienced endurance athletes underwent 3-Tesla brain MRI exams 2-3 days prior and within 2 days after a marathon run. MRI results were compared to an age- and sex-matched control group of 68 non-athletes, including the "Age-Related White Matter Changes" (ARWMC) scale to assess white matter lesions (WML) in the brain. 108 athletes (median age 48 years, 24% female, 8% with hypertension; 0% with diabetes) completed the race. No athlete reported neurological deficits, but a single acute ischemic lesion was detected in diffusion-weighted MRI after the race in one athlete. No other acute brain lesions compared to prior MRI were found. An ARWMC score ≥4 was found in 15% of athletes and 12% of non-athletic controls (p=0.7). Chronic ischemic lesions were not found in athletes but in four controls (6%) (p=0.02). In conclusion, acute ischemic brain lesions may be found in endurance runners. Every seventh endurance athlete and every ninth control showed evidence for substantial white matter lesions.


Assuntos
Comportamento Competitivo/fisiologia , Resistência Física/fisiologia , Corrida/fisiologia , Substância Branca/diagnóstico por imagem , Adulto , Arritmias Cardíacas/epidemiologia , Berlim/epidemiologia , Isquemia Encefálica/epidemiologia , Imagem de Difusão por Ressonância Magnética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
13.
Artigo em Inglês | MEDLINE | ID: mdl-31505855

RESUMO

Entry to specialist police tactical teams is governed by performance on a physically intense and psychologically demanding selection course. The aim of this study was to determine the attributes associated with completion of a specialist police selection course. Data pertaining to 18 candidates was obtained including 1 min push-ups, loaded pull-ups, loaded 30 m crawl, agility run, 1.2 km run and multi-stage fitness assessment. Comparisons from those who did and did not complete the selection week were performed and a hierarchical multiple regression performed. Eleven candidates finished, with significant difference found in those who completed the course in push-ups (+9.1 reps), loaded pull-ups (+2.9 reps), 1.2 km run (-16 s), loaded crawl (-6.3 s), agility (-0.67 s) and VO2max (+4.8 mL/kg/min). In combination, the fitness assessments pull-ups, 30 m loaded crawl and agility time were found to predict 70% of the variability in course completion (adjusted R2 = 0.70, F (3,14) = 14.373, p = 0.001). When assessed independently, push-ups, 1.2 km run and VO2max results only predicted a non-significant 0.02%, 0.29% and 0.12%, respectively, of course completion. Completion was influenced by aerobic fitness, upper limb strength and endurance and agility. These variables appear to be predictive of course success.


Assuntos
Teste de Esforço/estatística & dados numéricos , Resistência Física , Aptidão Física , Polícia/estatística & dados numéricos , Adulto , Estudos de Coortes , Humanos , Estudos Retrospectivos , Adulto Jovem
14.
Muscle Nerve ; 60(6): 779-789, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31509256

RESUMO

INTRODUCTION: Myotonic dystrophy type 1 (DM1) is a multisystemic disease caused by expansion of a CTG repeat in the 3' UTR of the Dystrophia Myotonica-Protein Kinase (DMPK) gene. While multiple organs are affected, more than half of mortality is due to muscle wasting. METHODS: It is unclear whether endurance exercise provides beneficial effects in DM1. Here, we show that a 10-week treadmill endurance exercise program leads to beneficial effects in the HSALR mouse model of DM1. RESULTS: Animals that performed treadmill training displayed reduced CUGexp RNA levels, improved splicing abnormalities, an increase in skeletal muscle weight and improved endurance capacity. DISCUSSION: These results indicate that endurance exercise does not have adverse effects in HSALR animals and contributes to beneficial molecular and physiological outcomes.


Assuntos
Treino Aeróbico/métodos , Músculo Esquelético/metabolismo , Distrofia Miotônica/metabolismo , Condicionamento Físico Animal/métodos , Resistência Física/fisiologia , Actinas/genética , Tecido Adiposo , Processamento Alternativo , Animais , Composição Corporal , Densidade Óssea , Modelos Animais de Doenças , Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Distrofia Miotônica/patologia , Distrofia Miotônica/fisiopatologia , Tamanho do Órgão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Expansão das Repetições de Trinucleotídeos
15.
J Sports Sci ; 37(23): 2691-2701, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31526108

RESUMO

This study investigated effects of total sleep deprivation on self-paced endurance performance, and heart rate (HR) indices of athletes' "readiness to perform". Endurance athletes (n = 13) completed a crossover experiment comprising a normal sleep (NS) and sleep deprivation (SD) condition. Each required completion of an endurance time-trial (TT) on consecutive days (D1, D2) separated by normal sleep or total sleep deprivation. Finishing time, perceived exertion (RPE), mood, psychomotor vigilance (PVT), and HR responses were assessed. Time on D2 of SD was 10% slower than D2 of NS (64 ± 7 vs 59 ± 4 min, P < 0.01), and 11% slower than D1 of SD (58 ± 5 min, P < 0.01). Subjective to objective (RPE:mean HR) intensity ratio was higher on D2 of SD compared with D2 of NS and D1 of SD (P < 0.01). Mood disturbance and PVT mean response time increased on D2 of SD compared with D2 of NS and D1 of SD. Anaerobic threshold and change in TT time were correlated (R = -0.73, P < 0.01). Sleep helps to optimise endurance performance. Subjective to objective intensity ratios appear sensitive to effects of sleep on athletes' readiness. Research examining more subtle sleep manipulation is required.


Assuntos
Ciclismo/fisiologia , Frequência Cardíaca/fisiologia , Resistência Física/fisiologia , Privação do Sono/fisiopatologia , Actigrafia/instrumentação , Adulto , Afeto/fisiologia , Ciclismo/psicologia , Estudos Cross-Over , Teste de Esforço , Humanos , Masculino , Percepção/fisiologia , Esforço Físico/fisiologia , Tempo de Reação/fisiologia , Dispositivos Eletrônicos Vestíveis
16.
Int J Sports Physiol Perform ; 14(8): 1151-1156, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31484159

RESUMO

Training-intensity distribution (TID), or the intensity of training and its distribution over time, has been considered an important determinant of the outcome of a training program in elite endurance athletes. The polarized and pyramidal TID, both characterized by a high amount of low-intensity training (below the first lactate or ventilatory threshold), but with different contributions of threshold training (between the first and second lactate or ventilatory threshold) and high-intensity training (above the second lactate or ventilatory threshold), have been reported most frequently in elite endurance athletes. However, the choice between these 2 TIDs is not straightforward. This article describes the historical, evolutionary, and physiological perspectives of the success of the polarized and pyramidal TID and proposes determinants that should be taken into account when choosing the most appropriate TID.


Assuntos
Desempenho Atlético/fisiologia , Condicionamento Físico Humano , Resistência Física/fisiologia , Atletas , Humanos , Ácido Láctico/sangue , Consumo de Oxigênio
17.
Int J Sports Med ; 40(12): 747-755, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31476783

RESUMO

Concurrent resistance and aerobic training (CT) has been applied to optimize both strength and aerobic performance. However, it should be carefully prescribed, as there are some factors, as the training intensity, which have strong influence on training adaptations. Thus, we conducted a systematic review to analyze the scientific evidence regarding aerobic and resistance exercise intensities during CT and their effect on performance outcomes. The effects of exercise intensity on a subsequent detraining period were also assessed. Nine studies met the inclusion criteria, the risk of bias was assessed, and the percentage of changes and effect sizes were quantified. CT improved running times (10 m, 30 m and 10 km) and strength performance (one-repetition maximum, countermovement jump) regardless of exercise intensity used (4-47%, ES=0.4-2.8). Nevertheless, higher aerobic training intensities (≥ lactate threshold intensity) resulted in higher aerobic gains (5-10%, ES=0.3-0.6), and greater neuromuscular adaptations were found when higher resistance loads (≥ 70% of maximal strength) were used (10-14%, ES=0.4-1.3). Most training-induced gains were reversed after 2-4 weeks of detraining. Although further research is needed, it seems that higher intensities of aerobic or resistance training induce greater aerobic or neuromuscular gains, respectively. Nevertheless, it seems that higher resistance training loads should be combined with lower aerobic training intensities for increased strength gains and minimal losses after detraining.


Assuntos
Força Muscular/fisiologia , Condicionamento Físico Humano/métodos , Resistência Física/fisiologia , Treinamento de Resistência/métodos , Adaptação Fisiológica , Humanos
19.
Medicina (Kaunas) ; 55(8)2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31408996

RESUMO

Background and Objectives: Soccer is the most popular sport in the world. To describe athletic performance, match statistics, and their relationships with the probability of achieving the first positions of the final ranking in the Italian football league "Serie A", season 2016/2017. Materials and Methods: Analyses comprised all the matches played by the 20 teams of the "Serie A" championship during the season 2016-2017. Indicators of athletic performance (total distance covered in km, jogging, running and sprint activities, and average speed) and match statistics (total shots, shots on target, goal attempts, assists, turnovers, and steals) were obtained from the Italian football league. Results: Analyses of performance activities according to the final ranking showed no significant differences for the total distance covered and speed, while a statistically significant difference (p < 0.05) among teams was observed for jogging, running and sprint activities. In regard to match statistics, all the parameters investigated were significantly different among the teams. By grouping teams into four subgroups (those who qualified for the Champions League, those who qualified for the Europe League, those who ranked intermediate positions and those who relegated from the "Serie A" league), the percentage of jogging, running and sprint activities, as well as match statistics were significantly different among groups, with a downward trend for total shots, shots on target, goal attempts, assists, and turnovers. The logistic regression analysis revealed that sprint activities as well as total shots, shots on target, goal attempts, and assists higher than the 3rd tertile of their distribution were associated with a higher probability of reaching the first three positions of the final ranking. Conclusions: An increased probability to achieve the first positions of the final ranking in the Italian football league "Serie A" seemed to be mainly related to sprint activity, goal attempts, total shots, shots on target and assists.


Assuntos
Desempenho Atlético/estatística & dados numéricos , Comportamento Competitivo , Futebol/fisiologia , Desempenho Atlético/fisiologia , Europa (Continente) , Humanos , Resistência Física , Corrida
20.
Hum Mov Sci ; 67: 102507, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31394308

RESUMO

The aim of this study was to clarify the role of the prefrontal cortex (PFC) in physical effort regulation. We hypothesized that the PFC would be progressively involved in physical endurance through the engagement of cognitive inhibition, which would be necessary to maintain effort by inhibiting fatigue-related cues. This hypothesis was examined using a double-blind, sham-controlled, within-subjects study (N = 20) using high-definition (HD) transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex (dlPFC). Participants had to maintain a knee extensor contraction at 30% of their maximal force while simultaneously performing an Eriksen flanker task to evaluate their inhibition performance during the task. Anodal stimulation of the dlPFC influenced response to the cognitive task during exercise, as seen by slower response times and better accuracy. However, it did not lead to any measureable improvement in cognitive inhibition and did not influence endurance time. There was no correlation between cognitive inhibition and the maintenance of physical effort. This result does not indicate a relationship between cognitive inhibition and endurance performance. The contribution of the PFC in physical endurance could be explained through its involvement on decisional processes.


Assuntos
Resistência Física/fisiologia , Córtex Pré-Frontal/fisiologia , Cognição/fisiologia , Tomada de Decisões/fisiologia , Método Duplo-Cego , Eletromiografia/métodos , Exercício/fisiologia , Feminino , Humanos , Masculino , Contração Muscular/fisiologia , Tempo de Reação/fisiologia , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto Jovem
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