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1.
Eur J Transl Myol ; 33(4)2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38058287

RESUMO

A well-synchronized circadian system is a manifestation of an individual's health. A gradual weakening of the circadian timing function characterizes aging. Regular exercise has been suggested as a modality to improve many detrimental changes associated with aging. Therefore, we aim to examine the benefits and risks of lifelong endurance exercise on age-dependent changes in the circadian time-keeping function, the performance of the muscular system and health status. The study protocol has a comparative cross-sectional design, including groups of senior (65 to 75 years old, n=16) and young (20-30 years old, n=16) endurance runners and triathletes. Age-matched groups of young and elderly sedentary men are included as controls. The circadian function is evaluated mainly by measurement of urinary 6-sulphatoxymelatonin, a metabolite of the hormone melatonin shown to participate in the modulation of sleep cycles. The 6-sulphatoxymelatonin will be assessed in urine samples collected upon awakening in the morning and in the late evening, as a marker of melatonin production. In addition, sleep/activity rhythms and sleep quality will be measured by wrist actigraphy. Performance of the muscular system will be assessed by examination of muscular strength and quantifying of gene expression in the skeletal muscle tissue samples. Health status and age-induced reduction in immune function are to be analysed via the balance of pro- and anti-inflammatory immune markers in the plasma and skeletal muscle, body composition, bone density and physical fitness.

2.
Eur J Transl Myol ; 33(2)2023 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-37052052

RESUMO

Low Energy Availability (LEA) arises from the inability to cover energy needs and requirements of training or normal physiological functions. This value differs from the energy balance, which takes into account the total daily energy intake compared to all the energy expended, regardless of the amount of fat-free mass. Insufficient energy consumption affects recovery, adaptation processes, increases the risk of injury or illness, so all of this can negatively affect performance. This mini-review is written on research articles in Pubmed database related to LEA in endurance-trained men and its impact on performance and testosterone. This article also clarifies the prevalence of LEA in male endurance athletes and its correlation to Relative Energy Deficiency in Sports (RED-S). LEA occurs in male endurance athletes and correlates with decreased testosterone levels, decreased bone density and also Resting Metabolic Rate. In endurance-trained men, there is great potential for the negative consequences of low energy availability. It can also be said that there are possibilities for primary screening, so we recommend regular check-ups of blood markers, body structure and keeping not only training but also dietary records, which can increase awareness of an adequate energy balance.

3.
Artigo em Inglês | MEDLINE | ID: mdl-36293774

RESUMO

Regular physical activity, recommended by the WHO, is crucial in maintaining a good physical fitness level and health status and slows down the effects of aging. However, there is a lack of knowledge of whether lifelong endurance running, with a volume and frequency above the WHO limits, still brings the same benefits, or several negative effects too. The present study aims to examine the protentional benefits and risks of lifelong endurance running training in Master male athletes, as this level of physical activity is above the WHO recommendations. Within the study, four main groups of participants will be included: (1) endurance-trained master athletes, (2) endurance-trained young athletes, (3) young sedentary adults, and (4) elderly sedentary. Both groups of athletes are strictly marathon runners, who are still actively running. The broad spectrum of the diagnostic tests, from the questionnaires, physical fitness testing, and blood sampling to muscle biopsy, will be performed to obtain the possibility of complexly analyzing the effects of lifelong endurance physical activity on the human body and aging. Moreover, the study will try to discover and explain new relationships between endurance running and diagnostic parameters, not only within aging.


Assuntos
Resistência Física , Corrida , Adulto , Humanos , Masculino , Idoso , Resistência Física/fisiologia , Corrida/fisiologia , Atletas , Envelhecimento/fisiologia , Aptidão Física
4.
Chronobiol Int ; 39(7): 1006-1014, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35473436

RESUMO

This study aimed to determine if time-of-day could influence physical volleyball performance in females and to explore the relationship between chronotype and volleyball-specific performance. Fifteen young female athletes participated in a randomized counterbalanced trial, performing a neuromuscular test battery in the morning (9:00 h) and the evening (19:00 h) that consisted of volleyball standing spike, straight leg raise, dynamic balance, vertical jump, modified agility T-test and isometric handgrip tests. Chronotype was determined by the morningness-eveningness questionnaire. Compared to the morning, an increased performance was found in the standing spike (4.5%, p = .002, ES = 0.59), straight leg raise test (dominant-limb) (6.5%, p = .012, ES = 0.40), dynamic balance (non-dominant-limb) (5.0%, p = .010, ES = 0.57) and modified T-test (2.1%, p = .049, ES = 0.45) performance in the evening; while no statistical differences were reported in vertical jump tests or isometric handgrip strength. Moreover, no associations were found between chronotype and neuromuscular performance (r = -0.368-0.435, p = .052-0.439). Time-of-day affected spike ball velocity, flexibility in the dominant-limb, dynamic balance in the non-dominant-limb and agility tests. However, no association was reported among these improvements and the chronotype. Therefore, although the chronotype may not play critical role in volleyball-specific performance, evening training/matches schedules could benefit performance in semi-professional female volleyball players.


Assuntos
Desempenho Atlético , Voleibol , Ritmo Circadiano , Feminino , Força da Mão , Humanos , Inquéritos e Questionários
5.
Eur J Transl Myol ; 32(1)2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35234026

RESUMO

In 2013 we presented results showing that at the histological level lifelong increased physical activity promotes reinnervation of muscle fibers in aging muscles. Indeed, in muscle biopsies from 70-year old men with a lifelong history of high-level physical activity, we observed a considerable increase in fiber-type groupings (F-TG), almost exclusively of the slow type. Slow-type transformation by denervation-reinnervation in senior sportsmen seems to fluctuate from those with scarce fiber-type transformation and groupings to almost fully transformed muscle, going through a process in which isolated fibers co-expressing fast and slow Myosin Heavy Chains (MHCs) seems to fill the gaps. Taken together, our results suggest that, beyond the direct effects of aging on the muscle fibers, changes occurring in skeletal muscle tissue appear to be largely, although not solely, a result of sparse denervation-reinnervation. The lifelong exercise allows the body to adapt to the consequences of the age-related denervation and to preserve muscle structure and function by saving otherwise lost muscle fibers through recruitment to different, mainly slow, motor units. These beneficial effects of high-level life-long exercise on motoneurons, specifically on the slow type motoneurones that are those with higher daily activity, and on muscle fibers, serve to maintain size, structure and function of muscles, delaying the functional decline and loss of independence that are commonly seen in late aging. Several studies of independent reserchers with independent analyses confirmed and cited our 2013 results. Thus, the results we presented in our paper in 2013 seem to have held up rather well.

6.
Gerontology ; 68(2): 151-161, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33971654

RESUMO

BACKGROUND/AIMS: Walking speed (WS) is an objective measure of physical capacity and a modifiable risk factor of morbidity and mortality in the elderly. In this study, we (i) determined effects of 3-month supervised aerobic-strength training on WS, muscle strength, and habitual physical activity; (ii) evaluated capacity of long-term (21 months) training to sustain higher WS; and (iii) identified determinants of WS in the elderly. METHODS: Volunteers (F 48/M 14, 68.4 ± 7.1 years) completed either 3-month aerobic-strength (3 × 1 h/week, n = 48) or stretching (active control, n = 14) intervention (study A). Thirty-one individuals (F 24/M 7) from study A continued in supervised aerobic-strength training (2 × 1 h/week, 21 months) and 6 (F 5/M 1) became nonexercising controls. RESULTS: Three-month aerobic-strength training increased preferred and maximal WS (10-m walk test, p < 0.01), muscle strength (p < 0.01) and torque (p < 0.01) at knee extension, and 24-h habitual physical activity (p < 0.001), while stretching increased only preferred WS (p < 0.03). Effect of training on maximal WS was most prominent in individuals with baseline WS between 1.85 and 2.30 m·s-1. Maximal WS measured before intervention correlated negatively with age (r = -0.339, p = 0.007), but this correlation was weakened by the intervention (r = -0.238, p = 0.06). WS progressively increased within the first 9 months of aerobic-strength training (p < 0.001) and remained elevated during 21-month intervention (p < 0.01). Cerebellar gray matter volume (MRI) was positively associated with maximal (r = 0.54; p < 0.0001) but not preferred WS and explained >26% of its variability, while age had only minor effect. CONCLUSIONS: Supervised aerobic-strength training increased WS, strength, and dynamics of voluntary knee extension as well as habitual physical activity in older individuals. Favorable changes in WS were sustainable over the 21-month period by a lower dose of aerobic-strength training. Training effects on WS were not limited by age, and cerebellar cortex volume was the key determinant of WS.


Assuntos
Treinamento Resistido , Idoso , Exercício Físico/fisiologia , Humanos , Força Muscular , Torque , Caminhada/fisiologia , Velocidade de Caminhada
7.
J Appl Biomed ; 19(2): 83-90, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34907707

RESUMO

The purpose of this study was to determine the changes in the resting level of serum cortisol, testosterone and T/C ratio in response to different training modalities and their variations. A secondary purpose was to identify if the various six weeks training programs are an effective way to improve physical fitness. 86 regularly active young males were assigned to one of six groups: Endurance constant running (ECR), Endurance interval running (EIR), Resistance training (RT), Explosive training (ET), Speed-endurance 50 m running (SER50) and Speed-endurance 150 m running (SER150) training. The resting levels of testosterone, cortisol and T/C ratio, as well as physical fitness, were measured. The ECR, EIR, and RT training program decreased COR level (P < 0.05). An increase of the T/C ratio was observed in the ECR and EIR group (P < 0.05). Except for SER50, each training program improved physical fitness. Our results suggest that endurance and resistance training modalities performed with a moderate to vigorous intensity may be a usable way to manage the resting cortisol level and enhance physical fitness in active young males.


Assuntos
Treinamento Resistido , Corrida , Humanos , Hidrocortisona , Masculino , Aptidão Física/fisiologia , Treinamento Resistido/métodos , Corrida/fisiologia , Testosterona
8.
Andrology ; 9(6): 1879-1892, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34245663

RESUMO

BACKGROUND: Testicular germ cell tumors (TGCTs) represent ∼95% of testicular malignancies and are the most common type of malignancy in young male adults. While the incidence of TGCTs has increased during the last decades, the advances in treatment, namely introducing cisplatin into the chemotherapy regimen, have made TGCTs highly curable with the 10-year survival rate exceeding 95%. However, in parallel with increased cure rates, survivors may experience acute and late adverse effects of treatment, which increase morbidity, reduce the quality of life, and can be potentially life-threatening. Chemotherapy-related toxicities include cardiovascular and metabolic diseases, secondary cancer, avascular necrosis, cognitive impairment, cancer-related fatigue, poor mental health-related quality of life, nephrotoxicity, hypogonadism, neurotoxicity, pulmonary toxicity, anxiety, and depression. These treatment-related adverse effects have emerged as important survivorship dilemmas in TGCT cancer survivors. Recently, regular physical exercise has increasingly attracted research and clinical attention as an adjunct therapy for cancer patients. PURPOSE: Herein, we review the most common chemotherapy-related adverse effects in TGCT survivors and clinical relevance of exercise and increased cardio-respiratory fitness in modulating chemotherapy-related toxicity and quality of life in this population. RESULTS AND CONCLUSION: Exercise has positive effects on a spectrum of physical and psychosocial outcomes during and after cancer treatment, and current guidelines on exercise prescription in chronic diseases define the recommended dose (volume and intensity) of regular exercise for cancer survivors, highlighting regular, sufficiently intensive physical activity as an essential part of patients' care.


Assuntos
Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Exercício Físico/fisiologia , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Aptidão Física/fisiologia , Neoplasias Testiculares/tratamento farmacológico , Adolescente , Adulto , Idoso , Sobreviventes de Câncer , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Embrionárias de Células Germinativas/fisiopatologia , Neoplasias Testiculares/fisiopatologia , Adulto Jovem
9.
Sports Med ; 51(7): 1561-1580, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33871831

RESUMO

INTRODUCTION: Understanding the impact of lockdown upon resistance training (RT), and how people adapted their RT behaviours, has implications for strategies to maintain engagement in similar positive health behaviours. Further, doing so will provide a baseline for investigation of the long-term effects of these public health measures upon behaviours and perceptions, and facilitate future follow-up study. OBJECTIVES: To determine how the onset of coronavirus (COVID-19), and associated 'lockdown', affected RT behaviours, in addition to motivation, perceived effectiveness, enjoyment, and intent to continue, in those who regularly performed RT prior to the pandemic. METHODS: We conducted an observational, cross-sectional study using online surveys in multiple languages (English, Danish, French, German, Italian, Portuguese, Slovakian, Swedish, and Japanese) distributed across social media platforms and through authors' professional and personal networks. Adults (n = 5389; median age = 31 years [interquartile range (IQR) = 25, 38]), previously engaged in RT prior to lockdown (median prior RT experience = 7 years [IQR = 4, 12]) participated. Outcomes were self-reported RT behaviours including: continuation of RT during lockdown, location of RT, purchase of specific equipment for RT, method of training, full-body or split routine, types of training, repetition ranges, exercise number, set volumes (per exercise and muscle group), weekly frequency of training, perception of effort, whether training was planned/recorded, time of day, and training goals. Secondary outcomes included motivation, perceived effectiveness, enjoyment, and intent to continue RT. RESULTS: A majority of individuals (82.8%) maintained participation in RT during-lockdown. Marginal probabilities from generalised linear models and generalised estimating equations for RT behaviours were largely similar from pre- to during-lockdown. There was reduced probability of training in privately owned gyms (~ 59% to ~ 7%) and increased probability of training at home (~ 18% to ~ 89%); greater probability of training using a full-body routine (~ 38% to ~ 51%); reduced probability of resistance machines (~ 66% to ~ 13%) and free weight use (~ 96% to ~ 81%), and increased probability of bodyweight training (~ 62% to ~ 82%); reduced probability of moderate repetition ranges (~ 62-82% to ~ 55-66%) and greater probability of higher repetition ranges (~ 27% to ~ 49%); and moderate reduction in the perception of effort experienced during-training (r = 0.31). Further, individuals were slightly less likely to plan or record training during lockdown and many changed their training goals. Additionally, perceived effectiveness, enjoyment, and likelihood of continuing current training were all lower during-lockdown. CONCLUSIONS: Those engaged in RT prior to lockdown these behaviours with only slight adaptations in both location and types of training performed. However, people employed less effort, had lower motivation, and perceived training as less effective and enjoyable, reporting their likelihood of continuing current training was similar or lower than pre-lockdown. These results have implications for strategies to maintain engagement in positive health behaviours such as RT during-restrictive pandemic-related public health measures. PRE-REGISTRATION: https://osf.io/qcmpf . PREPRINT: The preprint version of this work is available on SportRχiv: https://osf.io/preprints/sportrxiv/b8s7e/ .


Assuntos
COVID-19 , Controle de Doenças Transmissíveis , Treinamento Resistido , Adulto , COVID-19/prevenção & controle , Estudos Transversais , Seguimentos , Humanos , Saúde Pública
10.
J Strength Cond Res ; 35(4): 1074-1081, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30829983

RESUMO

ABSTRACT: Sedliak, M, Sedliak, P, and Vaara, JP. Effects of 6-month military deployment on physical fitness, body composition, and selected health-related biomarkers. J Strength Cond Res 35(4): 1074-1081, 2021-The purpose was to study the effects of 6-month deployment to Afghanistan on physical performance, anthropometrical, and health-related biochemical parameters in soldiers with sedentary to light physical workload shifts. Twenty-five male soldiers (30 ± 4 years) volunteered and were measured before and after the 6-month deployment. Another 25 home-land-based male soldiers (30 ± 6 years) served as controls. Total body fat percentage decreased in deployed soldiers (Pre: 23.2 ± 5.3 vs. Post: 20.8 ± 5.5%, p < 0.05), whereas no change was observed in control (20.2 ± 6.9 vs. 20.5 ± 7.0%). Physical performance improved in deployed soldiers in 4 × 10-m shuttle run (10.86 ± 0.90 vs. 10.49 ± 0.63 seconds) and pull-up test to failure (4.7 ± 3.7 vs. 7.5 ± 6.7 rep.) (p < 0.05) but not in the controls for the respective tests (10.28 ± 0.74 vs. 10.40 ± 0.76 seconds and 10.2 ± 7.8 vs. 10.2 ± 7.5 rep.). Deployed soldiers also improved 5-km run with a simulated combat gear time (29.2 ± 3.1 vs. 27.4 ± 3.0 minutes), whereas in control the time increased (26.4 ± 2.9 vs. 27.8 ± 2.6 minutes, p < 0.05). Load at maximum power output in bench press was improved in deployed soldiers (51.6 ± 11.3 vs. 56.2 ± 12.6 kg, p < 0.05). Serum glucose and creatinine decreased (5.46 ± 0.53 vs. 4.87 ± 0.74 mmol·L-1 and 87.4 ± 10.7 vs. 80.9 ± 10.2 µmmol·L-1, respectively), and hemoglobin and hematocrite increased (15.13 ± 0.82 vs. 16.75 ± 0.85 g·dl-1 and 45.3 ± 1.5 vs. 48.1 ± 2.4%, respectively, p < 0.05) in the deployment group. In conclusion, after 6-month deployment consisting of sedentary and low physical occupational load, soldiers were able to increase their physical fitness and decrease their body fat content and improve selected health-related biochemical parameters. Therefore, the adoption and promotion of leisure-time physical activity in soldiers during deployments is essential to maintain combat readiness.


Assuntos
Destacamento Militar , Militares , Biomarcadores , Composição Corporal , Humanos , Masculino , Aptidão Física
11.
Vnitr Lek ; 66(2): 71-76, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32942891

RESUMO

INTRODUCTION: The objective of the study was to examine the relationship between the values of selected parameters of physical function, body composition, body mass index (BMI) and biochemical markers of metabolic health with the total testosterone (TT) levels in adult males. We aimed to analyse the correlation between these values and variations in the TT levels. METHODS: A total of 17 subjects (age = 50.2 ± 8.1 years, TT = 11.4 ± 3.8nmol/l) were included in the study. Subjects were tested on physical function (1RM on leg press, bench-press, handgrip, VO2max), body composition (DXA), biochemical parameters (morning fasting blood samples). RESULTS: TT was inversely correlated with abdominal circumference (AC) (p.


Assuntos
Força da Mão , Testosterona , Adulto , Composição Corporal , Índice de Massa Corporal , Jejum , Humanos , Masculino
12.
Eur J Transl Myol ; 30(1): 8820, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32499886

RESUMO

The study compared the effect of 12-week multimodal training programme performed twice a week at the regular exercise facility (REF) with the 12-week multimodal training programme performed three times per week as a part of the research programme (EX). Additionally, the study analysed how the experimental training programme affect the physical performance of cognitive healthy and mild cognitive impaired elderly (MCI). The REF training group included 19 elderly (65.00±3.62 years). The experimental training programme combined cognitively healthy (EXH: n=16; 66.3±6.42 years) and age-matched individuals with MCI (EXMCI: n=14; 66.00±4.79 years). 10m maximal walking speed (10mMWS), Five Times Sit-to-Stand Test (FTSS), maximal and relative voluntary contraction (MVC & rel. MVC) were analysed. The REF group improved in 10mMWS (t=2.431, p=.026), the MVC (t=-3.528, p=.002) and relative MVC (t=3.553, p=.002). The EXH group improved in FTSS (t=5.210, P=.000), MVC (t=2.771, p=.018) and relative MVC (t=-3.793, p=.004). EXMCI improved in FTSS (t=2.936, p=.012) and MVC (t=-2.276, p=.040). According to results, both training programmes sufficiently improved walking speed and muscle strength in cognitively healthy elderly. Moreover, the experimental training programme improved muscle strength in MCI elderly.

13.
Neuropeptides ; 78: 101961, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31506171

RESUMO

Brain-derived neurotrophic factor (BDNF) participates in orchestrating the adaptive response to exercise. However, the importance of transient changes in circulating BDNF for eliciting whole-body and skeletal muscle exercise benefits in humans remains relatively unexplored. Here, we investigated effects of acute aerobic exercise and 3-month aerobic-strength training on serum, plasma and skeletal muscle BDNF in twenty-two sedentary older individuals (69.0 ±â€¯8.0 yrs., 9 M/13F). BDNF response to acute exercise was additionally evaluated in young trained individuals (25.1 ±â€¯2.1 yrs., 3 M/5F). Acute aerobic exercise transiently increased serum BDNF in sedentary (16%, p = .007) but not in trained elderly or young individuals. Resting serum or plasma BDNF was not regulated by exercise training in the elderly. However, subtle training-related changes of serum BDNF positively correlated with improvements in walking speed (R = 0.59, p = .005), muscle mass (R = 0.43, p = .04) and cognitive performance (R = 0.41, p = .05) and negatively with changes in body fat (R = -0.43, p = .04) and triglyceridemia (R = -0.53, p = .01). Individuals who increased muscle BDNF protein in response to 3-month training (responders) displayed stronger acute exercise-induced increase in serum BDNF than non-responders (p = .006). In addition, muscle BDNF protein content positively correlated with type II-to-type I muscle fiber ratio (R = 0.587, p = .008) and with the rate of post-exercise muscle ATP re-synthesis (R = 0.703, p = .005). Contrary to serum, acute aerobic exercise resulted in a decline of plasma BDNF 1 h post-exercise in both elderly-trained (-34%, p = .002) and young-trained individuals (-48%, p = .034). Acute circulating BDNF regulation by exercise was dependent on the level of physical fitness and correlated with training-induced improvements in metabolic and cognitive functions. Our observations provide an indirect evidence that distinct exercise-induced changes in serum and plasma BDNF as well as training-related increase in muscle BDNF protein, paralleled by improvements in muscle and whole-body clinical phenotypes, are involved in the coordinated adaptive response to exercise in humans.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Cognição/fisiologia , Exercício Físico/fisiologia , Músculo Esquelético/metabolismo , Treinamento Resistido , Adulto , Idoso , Fator Neurotrófico Derivado do Encéfalo/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio/fisiologia , Aptidão Física/fisiologia , Adulto Jovem
14.
BMJ Open ; 9(9): e025991, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31492775

RESUMO

INTRODUCTION: Androgen deficiency of the ageing male is a clinical syndrome resulting from the low production of androgens (testosterone levels <6.9 nmol/L) with symptoms including decline in lean mass, muscle strength, increases in body mass and overall fat mass. The aim of the study is to examine the effect of a 12 week strength training intervention on body composition, physical function, muscle cellular and molecular and selected biochemical markers of metabolic health in hypogonadal patients. METHODS AND ANALYSIS: The study is three-group controlled 12-week experiment to assess the effect of strength training on hypogonadal patients with testosterone replacement therapy and newly diagnosed males without testosterone replacement therapy. Age matched healthy eugonadal males are also engaged in strength training. Lean mass is used to determine sample size indicating, that 22 subjects per group will be sufficient to detect intervention related changes at the power of 0.90. All outcomes are collected before the intervention (pre-intervention assessments) and after the intervention (post-intervention assessments). Clinical outcomes are body composition (lean mass, fat mass and total body mass) measured by dual-energy X-ray absorptiometry, physical functioning assessed by physical tests and psychosocial functioning. The most important haematological and biochemical parameters included are glucose, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, testosterone, luteinizing hormone, follicle-stimulating hormone, sexhormone-binding globulin, insulin and prostate-specific antigen. Muscle cellular and molecular outcomes are muscle fibre size and regulators of muscle fibre size. Muscle cellular outcomes are measured from muscle biopsies obtained from musculus vastus lateralis. ETHICS AND DISSEMINATION: This trial is approved by Ethics Committee of the University Hospital in Bratislava, Slovakia, (ref. trial number: 127/2017) and all subjects will be fully informed on the rationale, risks and benefits of the study and sign the written informed consent prior to entering the study. Results will be published in peer-reviewed journals and presented in scientific conferences. TRIAL REGISTRATION NUMBER: NCT03282682.


Assuntos
Terapia de Reposição Hormonal , Hipogonadismo/terapia , Músculo Esquelético/fisiopatologia , Treinamento Resistido/métodos , Testosterona/uso terapêutico , Absorciometria de Fóton , Envelhecimento/fisiologia , Composição Corporal , Terapia Combinada , Ensaios Clínicos Controlados como Assunto , Humanos , Hipogonadismo/etiologia , Masculino , Estudos Multicêntricos como Assunto , Força Muscular , Músculo Esquelético/anatomia & histologia , Eslováquia
15.
Chronobiol Int ; 35(4): 450-464, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29283292

RESUMO

It has been clearly established that maximal force and power is lower in the morning compared to noon or afternoon hours. This morning neuromuscular deficit can be diminished by regularly training in the morning hours. However, there is limited and contradictory information upon hypertrophic adaptations to time-of-day-specific resistance training. Moreover, no cellular or molecular mechanisms related to muscle hypertrophy adaptation have been studied with this respect. Therefore, the present study examined effects of the time-of-day-specific resistance training on muscle hypertrophy, phosphorylation of selected proteins, hormonal concentrations and neuromuscular performance. Twenty five previously untrained males were randomly divided into a morning group (n = 11, age 23 ± 2 yrs), afternoon group (n = 7, 24 ± 4 yrs) and control group (n = 7, 24 ± 3 yrs). Both the morning and afternoon group underwent hypertrophy-type of resistance training with 22 training sessions over an 11-week period performed between 07:30-08:30 h and 16:00-17:00 h, respectively. Isometric MVC was tested before and immediately after an acute loading exclusively during their training times before and after the training period. Before acute loadings, resting blood samples were drawn and analysed for plasma testosterone and cortisol. At each testing occasion, muscle biopsies from m. vastus lateralis were obtained before and 60 min after the acute loading. Muscle specimens were analysed for muscle fibre cross-sectional areas (CSA) and for phosphorylated p70S6K, rpS6, p38MAPK, Erk1/2, and eEF2. In addition, the right quadriceps femoris was scanned with MRI before and after the training period. The control group underwent the same testing, except for MRI, between 11:00 h and 13:00 h but did not train. Voluntary muscle strength increased significantly in both the morning and afternoon training group by 16.9% and 15.2 %, respectively. Also muscle hypertrophy occurred by 8.8% and 11.9% (MRI, p < 0.001) and at muscle fibre CSA level by 21% and 18% (p < 0.01) in the morning and afternoon group, respectively. No significant changes were found in controls within these parameters. Both pre- and post-training acute loadings induced a significant (p < 0.001) reduction in muscle strength in all groups, not affected by time of day or training. The post-loading phosphorylation of p70S6Thr421/Ser424 increased independent of the time of day in the pre-training condition, whereas it was significantly increased in the morning group only after the training period (p < 0.05). Phosphorylation of rpS6 and p38MAPK increased acutely both before and after training in a time-of-day independent manner (p < 0.05 at all occasions). Phosphorylation of p70S6Thr389, eEF2 and Erk1/2 did not change at any time point. No statistically significant correlations were found between changes in muscle fibre CSA, MRI and cell signalling data. Resting testosterone was not statistically different among groups at any time point. Resting cortisol declined significantly from pre- to post-training in all three groups (p < 0.05). In conclusion, similar levels of muscle strength and hypertrophy could be achieved regardless of time of the day in previously untrained men. However, at the level of skeletal muscle signalling, the extent of adaptation in some parameters may be time of day dependent.


Assuntos
Ritmo Circadiano , Hidrocortisona/sangue , Proteínas Musculares/metabolismo , Músculo Quadríceps/fisiologia , Treinamento Resistido/métodos , Testosterona/sangue , Adaptação Fisiológica , Adulto , Biomarcadores/sangue , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Contração Isométrica , Imageamento por Ressonância Magnética , Masculino , Força Muscular , Fator 2 de Elongação de Peptídeos/metabolismo , Fosforilação , Músculo Quadríceps/diagnóstico por imagem , Músculo Quadríceps/metabolismo , Proteína S6 Ribossômica/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Fatores de Tempo , Adulto Jovem , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
16.
Front Neurol ; 8: 698, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29312123

RESUMO

Regular exercise ameliorates motor symptoms in Parkinson's disease (PD). Here, we aimed to provide evidence that exercise brings additional benefits to the whole-body metabolism and skeletal muscle molecular and functional characteristics, which might help to explain exercise-induced improvements in the clinical state. 3-months supervised endurance/strength training was performed in early/mid-stage PD patients and age/gender-matched individuals (n = 11/11). The effects of exercise on resting energy expenditure (REE), glucose metabolism, adiposity, and muscle energy metabolism (31P-MRS) were evaluated and compared to non-exercising PD patients. Two muscle biopsies were taken to determine intervention-induced changes in fiber type, mitochondrial content, and expression of genes related to muscle energy metabolism, as well as proliferative and regenerative capacity. Exercise improved the clinical disability score (MDS-UPDRS), bradykinesia, balance, walking speed, REE, and glucose metabolism and increased muscle expression of energy sensors (AMPK). However, the exercise-induced increase in muscle mass/strength, mitochondrial content, type II fiber size, and postexercise phosphocreatine (PCr) recovery (31P-MRS) were found only in controls. Nevertheless, MDS-UPDRS was associated with muscle AMPK and mechano-growth factor (MGF) expression. Improvements in fasting glycemia were positively associated with muscle function and the expression of Sirt1 and Cox7a1, and the parameters of fitness/strength were positively associated with the expression of MyHC2, MyHC7, and MGF. Moreover, reduced bradykinesia was associated with better muscle metabolism (maximal oxidative capacity and postexercise PCr recovery; 31P-MRS). Exercise training improved the clinical state in early/mid-stage Parkinson's disease patients, including motor functions and whole-body metabolism. Although the adaptive response to exercise in PD was different from that of controls, exercise-induced improvements in the PD clinical state were associated with specific adaptive changes in muscle functional, metabolic, and molecular characteristics. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov, identifier NCT02253732.

17.
Appl Physiol Nutr Metab ; 41(12): 1285-1294, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27863207

RESUMO

This study investigated the effects of 24 weeks of morning versus evening same-session combined strength (S) and endurance (E) training on physical performance, muscle hypertrophy, and resting serum testosterone and cortisol diurnal concentrations. Forty-two young men were matched and assigned to a morning (m) or evening (e) E + S or S + E group (mE + S, n = 9; mS + E, n = 9; eE + S, n = 12; and eS + E, n = 12). Participants were tested for dynamic leg press 1-repetition maximum (1RM) and time to exhaustion (Texh) during an incremental cycle ergometer test both in the morning and evening, cross-sectional area (CSA) of vastus lateralis and diurnal serum testosterone and cortisol concentrations (0730 h; 0930 h; 1630 h; 1830 h). All groups similarly increased 1RM in the morning (14%-19%; p < 0.001) and evening (18%-24%; p < 0.001). CSA increased in all groups by week 24 (12%-20%, p < 0.01); however, during the training weeks 13-24 the evening groups gained more muscle mass (time-of-day main effect; p < 0.05). Texh increased in all groups in the morning (16%-28%; p < 0.01) and evening (18%-27%; p < 0.001), however, a main effect for the exercise order, in favor of E + S, was observed on both testing times (p < 0.051). Diurnal rhythms in testosterone and cortisol remained statistically unaltered by the training order or time. The present results indicate that combined strength and endurance training in the evening may lead to larger gains in muscle mass, while the E + S training order might be more beneficial for endurance performance development. However, training order and time seem to influence the magnitude of adaptations only when the training period exceeded 12 weeks.


Assuntos
Desempenho Atlético , Exercício Físico , Desenvolvimento Muscular , Força Muscular , Músculo Esquelético/fisiologia , Resistência Física , Treinamento Resistido , Adulto , Ciclismo , Ritmo Circadiano , Teste de Esforço , Fadiga/sangue , Fadiga/etiologia , Fadiga/prevenção & controle , Humanos , Hidrocortisona/sangue , Hipertrofia/prevenção & controle , Masculino , Músculo Esquelético/crescimento & desenvolvimento , Pacientes Desistentes do Tratamento , Músculo Quadríceps/crescimento & desenvolvimento , Músculo Quadríceps/fisiologia , Treinamento Resistido/efeitos adversos , Testosterona/sangue , Fatores de Tempo , Levantamento de Peso
18.
Chronobiol Int ; 32(8): 1115-24, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26361893

RESUMO

It has been clearly established that maximal force varies during the day in human muscles but the exact mechanisms behind the diurnal rhythms are still not fully clarified. Therefore, the aim of this study was to examine the diurnal rhythms in maximal isometric force production in a large group of participants and also by separating the high morning performance types (n = 8) and the high evening performance types (n = 19) from the neutral types (n = 45) based on their actual maximal isometric force levels. Measurements were performed in the morning (7:26 h ± 63 min) and in the evening (17:57 h ± 74 min) for maximal bilateral isometric leg press force (MVCLP) together with myoelectric activity (EMGLP), maximal unilateral isometric knee extension force (MVCKE) and maximal voluntary activation level (VA%) during maximal unilateral isometric knee extension force (MVCVA) together with myoelectric activity (EMGVA). In addition, venous blood samples were drawn four times a day and serum testosterone and cortisol concentrations were analyzed. None of the participants belonged to the extreme morning or evening chronotype according to the Munich Chronotype Questionnaire. In the total group of participants, MVCLP and MVCKE were 4.4 ± 12.9% (p < 0.01) and 4.3 ± 10.6% (p < 0.01) higher in the evening compared to the morning. MVCVA and VA% did not show significant diurnal variation. The high morning performance types showed lower force values in the evening compared to the morning for MVCLP (10.8 ± 9.1%; p < 0.05) and MVCKE (5.7 ± 4.9%; p < 0.05). No significant diurnal variation was observed for MVCVA and VA%. The high evening performance types showed higher force values in the evening for MVCLP (16.1 ± 15.9%; p < 0.001), MVCKE (13.5 ± 11.3%; p < 0.001) and MVCVA (6.2 ± 9.9%; p < 0.05) with a concomitant higher VA% in the evening (p < 0.05). The neutral types showed significantly higher evening force values for the MVCLP (2.1 ± 6.7%; p < 0.05). All the other neuromuscular variables did not show significant diurnal variations. EMGLP and EMGVA did not show significant diurnal fluctuations in any group. Serum testosterone and cortisol concentrations showed normal daily rhythms with higher values observed in the morning in all of the groups (p < 0.001). Between-group differences were observed for MVCLP (p < 0.001) and MVCKE (p < 0.001) between all of the three groups. Diurnal changes in VA% differed between the high evening performance types and the neutral types (p < 0.05) and the testosterone/cortisol ratio (p < 0.05) as well as vastus lateralis EMGVA (p < 0.05) differed between the high morning and high evening performance types. In conclusion, we were able to identify the high morning performance types, the high evening performance types and the neutral types who showed significantly different diurnal rhythms in force production, irrespective of their actual chronotype. Therefore, the questionnaires designed to determine the chronotype may not always be sensitive enough to determine the "morningness" or "eveningness" in maximal neuromuscular performance. In general, central factors could partially explain the diurnal fluctuations in maximal strength performance, but peripheral mechanisms were also possibly involved.


Assuntos
Ritmo Circadiano/fisiologia , Contração Isométrica/fisiologia , Músculo Quadríceps/fisiologia , Inquéritos e Questionários , Desempenho Profissional , Adulto , Eletromiografia/métodos , Humanos , Hidrocortisona/fisiologia , Masculino , Fatores de Tempo , Adulto Jovem
19.
Eur J Transl Myol ; 25(4): 237-42, 2015 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-26913162

RESUMO

Sarcopenia is the age-related loss of muscle mass and function, reducing force generation and mobility in the elderlies. Contributing factors include a severe decrease in both myofiber size and number as well as a decrease in the number of motor neurons innervating muscle fibers (mainly of fast type) which is sometimes accompanied by reinnervation of surviving slow type motor neurons (motor unit remodeling). Reduced mobility and functional limitations characterizing aging can promote a more sedentary lifestyle for older individuals, leading to a vicious circle further worsening muscle performance and the patients' quality of life, predisposing them to an increased risk of disability, and mortality. Several longitudinal studies have shown that regular exercise may extend life expectancy and reduce morbidity in aging people. Based on these findings, the Interreg IVa project aimed to recruit sedentary seniors with a normal life style and to train them for 9 weeks with either leg press (LP) exercise or electrical stimulation (ES). Before and at the end of both training periods, all the subjects were submitted to mobility functional tests and muscle biopsies from the Vastus Lateralis muscles of both legs. No signs of muscle damage and/or of inflammation were observed in muscle biopsies after the training. Functional tests showed that both LP and ES induced improvements of force and mobility of the trained subjects. Morphometrical and immunofluorescent analyses performed on muscle biopsies showed that ES significantly increased the size of fast type muscle fibers (p<0.001), together with a significant increase in the number of Pax7 and NCAM positive satellite cells (p<0.005). A significant decrease of slow type fiber diameter was observed in both ES and LP trained subjects (p<0.001). Altogether these results demonstrate the effectiveness of physical exercise either voluntary (LP) or passive (ES) to improve the functional performances of aging muscles. Here ES is demonstrated to be a safe home-based method to counteract fast type fiber atrophy, typically associated with aging skeletal muscle.

20.
Eur J Transl Myol ; 25(4): 249-52, 2015 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-26913164

RESUMO

Aging is a multifactorial irreversible process associated with significant decline in muscle mass and neuromuscular functions. One of the most efficient methods to counteract age-related changes in muscle mass and function is physical exercise. An alternative effective intervention to improve muscle structure and performance is electrical stimulation. In the present work we present the positive effects of physical activity in elderly and a study where the effects of a 8-week period of functional electrical stimulation and strength training with proprioceptive stimulation in elderly are compared.

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