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Beta-band activity in the sensorimotor cortex is considered a potential biomarker for evaluating motor functions. The intricate connection between the brain and muscle (corticomuscular coherence), especially in beta band, was found to be modulated by multiple motor demands. This coherence also showed abnormality in motion-related disorders. However, although there has been a substantial accumulation of experimental evidence, the neural mechanisms underlie corticomuscular coupling in beta band are not yet fully clear, and some are still a matter of controversy. In this review, we summarized the findings on the impact of Beta-band corticomuscular coherence to multiple conditions (sports, exercise training, injury recovery, human functional restoration, neurodegenerative diseases, age-related changes, cognitive functions, pain and fatigue, and clinical applications), and pointed out several future directions for the scientific questions currently unsolved. In conclusion, an in-depth study of Beta-band corticomuscular coupling not only elucidates the neural mechanisms of motor control but also offers new insights and methodologies for the diagnosis and treatment of motor rehabilitation and related disorders. Understanding these mechanisms can lead to personalized neuromodulation strategies and real-time neurofeedback systems, optimizing interventions based on individual neurophysiological profiles. This personalized approach has the potential to significantly improve therapeutic outcomes and athletic performance by addressing the unique needs of each individual.
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Montmorency cherry (MC) can improve endurance performance, but optimal pre-exercise timing of supplementation and influence of training status on efficacy are unknown. We investigated the effect of MC concentrate ingestion between 30- and 150-min pre-exercise in trained and recreational cyclists on 15-km time trial (TT) performance and exercise economy. Twenty participants (10 recreationally active, RA; 10 trained, T) completed 10 min of steady-state exercise (SSE) at 40%Δ (SSE) and a TT on four separate occasions following an unsupplemented (US), 30-, 90- or 150-min pre-exercise Montmorency cherry concentrate (MCC) supplementation conditions (MCC30/90/150min). Venous and capillary blood samples were taken at regular intervals pre- and post-SSE and TT. MCC significantly improved TT performance, but not exercise economy. The greatest improvement in performance occurred following MCC90min compared to US (US 1603.1 ± 248 s vs. MCC90min 1554.8 ± 226.7 s, 2.83% performance improvement). Performance was significantly enhanced for trained (US 1496.6 ± 173.1 s vs. MCC90min 1466.8 ± 157.6 s) but not recreationally active participants. Capillary [lactate] and heart rate were significantly greater during the TT for the 90-min dose timing (p < 0.05). In the MCC30min and MCC90min conditions, plasma ferulic (US 8.71 ± 3.22 nmol. L-1 vs. MCC30min 15.80 ± 8.69 nmol. L-1, MCC90min 12.65 ± 4.84 nmol. L-1) and vanillic acid (US 25.14 ± 10.91 nmol.L-1 vs. MCC30min 153.07 ± 85.91 nmol. L-1, MCC90min 164.58 ± 59.06 nmol. L-1) were significantly higher pre-exercise than in US and MCC150min conditions (p < 0.05). There was no significant change in muscle oxygenation status or plasma nitrite/nitrate concentration. MCC supplementation enhanced endurance exercise performance optimally when consumed â¼90 min pre-exercise producing maximal plasma phenolic metabolites during exercise. The ergogenic effect was greater for trained participants.
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Desempenho Atlético , Ciclismo , Suplementos Nutricionais , Ácido Láctico , Prunus avium , Humanos , Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Masculino , Adulto , Ácido Láctico/sangue , Resistência Física/fisiologia , Resistência Física/efeitos dos fármacos , Adulto Jovem , Consumo de Oxigênio , Fatores de Tempo , Frequência CardíacaRESUMO
BACKGROUND: While it has been examined whether there are similar magnitudes of muscle strength and hypertrophy adaptations between low-load resistance training combined with blood-flow restriction training (BFR-RT) and high-load resistance training (HL-RT), some important potential moderators (e.g., age, sex, upper and lower limbs, frequency and duration etc.) have yet to be analyzed further. Furthermore, training status, specificity of muscle strength tests (dynamic versus isometric or isokinetic) and specificity of muscle mass assessments (locations of muscle hypertrophy assessments) seem to exhibit different effects on the results of the analysis. The role of these influencing factors, therefore, remains to be elucidated. OBJECTIVES: The aim of this meta-analysis was to compare the effects of BFR- versus HL-RT on muscle adaptations, when considering the influence of population characteristics (training status, sex and age), protocol characteristics (upper or lower limbs, duration and frequency) and test specificity. METHODS: Studies were identified through database searches based on the following inclusion criteria: (1) pre- and post-training assessment of muscular strength; (2) pre- and post-training assessment of muscular hypertrophy; (3) comparison of BFR-RT vs. HL-RT; (4) score ≥ 4 on PEDro scale; (5) means and standard deviations (or standard errors) are reported or allow estimation from graphs. In cases where the fifth criterion was not met, the data were requested directly from the authors. RESULTS: The main finding of the present study was that training status was an important influencing factor in the effects of BFR-RT. The trained individuals may gain greater muscle strength and hypertrophy with BFR-RT as compared to HL-RT. However, the results showed that the untrained individuals experienced similar muscle mass gains and superior muscle strength gains in with HL-RT compared to BFR-RT. CONCLUSION: Compared to HL-RT, training status is an important factor influencing the effects of the BFR-RT, in which trained can obtain greater muscle strength and hypertrophy gains in BFR-RT, while untrained individuals can obtain greater strength gains and similar hypertrophy in HL-RT.
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This study aimed to investigate the relationship between pre- and postexercise cardiac biomarker release according to athletic status (trained vs. untrained) and to establish whether the I/D polymorphism in the angiotensin-converting enzyme (ACE) gene had an influence on cardiac biomarkers release with specific regard on the influence of the training state. We determined cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in 29 trained and 27 untrained male soccer players before and after moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) running tests. Trained soccer players had higher pre (trained: 0.014 ± 0.007 ng/mL; untrained: 0.010 ± 0.005 ng/mL) and post HIIE (trained: 0.031 ± 0.008 ng/mL; untrained: 0.0179 ± 0.007) and MICE (trained: 0.030 ± 0.007 ng/mL; untrained: 0.018 ± 0.007) cTnI values than untrained subjects, but the change with exercise (ΔcTnI) was similar between groups. There was no significant difference in baseline and postexercise NT-proBNP between groups. NT-proBNP levels were elevated after both HIIE and MICE. Considering three ACE genotypes, the mean pre exercise cTnI values of the trained group (DD: 0.015 ± 0.008 ng/mL, ID: 0.015 ± 0.007 ng/mL, and II: 0.014 ± 0.008 ng/mL) and their untrained counterparts (DD: 0.010 ± 0.004 ng/mL, ID: 0.011 ± 0.004 ng/mL, and II: 0.010 ± 0.006 ng/mL) did not show any significant difference. To sum up, noticeable difference in baseline cTnI was observed, which was related to athletic status but not ACE genotypes. Neither athletic status nor ACE genotypes seemed to affect the changes in cardiac biomarkers in response to HIIE and MICE, indicating that the ACE gene does not play a significant role in the release of exercise-induced cardiac biomarkers indicative of cardiac damage in Iranian soccer players.NEW & NOTEWORTHY Our study investigated the impact of athletic status and angiotensin-converting enzyme (ACE) gene I/D polymorphism on cardiac biomarkers in soccer players. Trained players showed higher baseline cardiac troponin I (cTnI) levels, whereas postexercise ΔcTnI remained consistent across groups. N-terminal pro-brain natriuretic peptide increased after exercise in both groups, staying within normal limits. ACE genotypes did not significantly affect pre-exercise cTnI. Overall, athletic status influences baseline cTnI, but neither it nor ACE genotypes significantly impact exercise-induced cardiac biomarker responses in this population.
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Biomarcadores , Exercício Físico , Peptídeo Natriurético Encefálico , Fragmentos de Peptídeos , Peptidil Dipeptidase A , Polimorfismo Genético , Troponina I , Masculino , Humanos , Peptidil Dipeptidase A/genética , Biomarcadores/sangue , Peptídeo Natriurético Encefálico/sangue , Peptídeo Natriurético Encefálico/genética , Troponina I/sangue , Troponina I/genética , Fragmentos de Peptídeos/sangue , Exercício Físico/fisiologia , Adulto Jovem , Adulto , Treinamento Intervalado de Alta Intensidade/métodos , Futebol/fisiologia , Mutação INDEL/genética , Coração/fisiologiaRESUMO
A better understanding of the cellular and molecular mechanisms that are involved in skeletal muscle adaptation to exercise is fundamentally important to take full advantage of the enormous benefits that exercise training offers in disease prevention and therapy. The aim of this study was to elucidate the transcriptional signatures that distinguish the endurance-trained and untrained muscles in young adult males (24 ± 3.5 years). We characterized baseline differences as well as acute exercise-induced transcriptome responses in vastus lateralis biopsy specimens of endurance-trained athletes (ET; n = 8; VO2max, 67.2 ± 8.9 mL/min/kg) and sedentary healthy volunteers (SED; n = 8; VO2max, 40.3 ± 7.6 mL/min/kg) using microarray technology. A second cohort of SED volunteers (SED-T; n = 10) followed an 8-week endurance training program to assess expression changes of selected marker genes in the course of skeletal muscle adaptation. We deciphered differential baseline signatures that reflected major differences in the oxidative and metabolic capacity of the endurance-trained and untrained muscles. SED-T individuals in the training group displayed an up-regulation of nodal regulators of oxidative adaptation after 3 weeks of training and a significant shift toward the ET signature after 8 weeks. Transcriptome changes provoked by 1 h of intense cycling exercise only poorly overlapped with the genes that constituted the differential baseline signature of ETs and SEDs. Overall, acute exercise-induced transcriptional responses were connected to pathways of contractile, oxidative, and inflammatory stress and revealed a complex and highly regulated framework of interwoven signaling cascades to cope with exercise-provoked homeostatic challenges. While temporal transcriptional programs that were activated in SEDs and ETs were quite similar, the quantitative divergence in the acute response transcriptomes implicated divergent kinetics of gene induction and repression following an acute bout of exercise. Together, our results provide an extensive examination of the transcriptional framework that underlies skeletal muscle plasticity.
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Treino Aeróbico , Transcriptoma , Masculino , Adulto Jovem , Humanos , Resistência Física/fisiologia , Músculo Esquelético/metabolismo , Exercício Físico/fisiologiaRESUMO
PURPOSE: To determine if post-exercise heart rate variability, in the form of logged transformed root mean square of successive differences of the R-R intervals (LnRMSSD) can be measured reliably during the recovery from a submaximal cycle test and what the relationship of LnRMSSD is with training status of the cyclists. METHODS: Fourteen male cyclists participated in the reliability part for the study, which included performing six Lamberts Submaximal Cycle Test (LSCT), during which recovery LnRMSSD was measured over 30 s (LnRMSSD30 s), 60 s LnRMSSD60 s)and 90 s LnRMSSD90 s). In addition, fifty male and twenty female cyclists completed a peak power output (PPO) test (including VO2peak) and 40 km time trial (40 km TT) before which they performed the LSCT as a standardized warm-up. Relationships between the LnRMSSD and PPO, VO2peak and 40 km TT time were studied. RESULTS: Due to the design of the LSCT, submaximal heart and breathing rate were similar at the end of stage 3 of the LSCT, as well as during the recovery periods. The highest reliability was found in LnRMSSD60 s (ICC: 0.97) with a typical error of the measurement (TEM: 5.8%). In line with this the strongest correlations were found between LnRMSSD60 s and PPO (r = 0.93[male]; 0.85[female]), VO2peak (r = 0.71[male]; 0.63[female];) and 40 km TT (r = - 0.83[male]; - 0.63[female]). CONCLUSIONS: LnRMSSD60 s can be measured reliably after the LSCT and can predict PPO, VO2peak and 40 km TT performance well in trained-to-elite cyclists. These findings suggest that recovery LnRMSSD can potentially play an important role in monitoring and fine-tuning training prescriptions in trained-to-elite cyclists.
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Ciclismo , Teste de Esforço , Frequência Cardíaca , Humanos , Masculino , Frequência Cardíaca/fisiologia , Ciclismo/fisiologia , Feminino , Adulto , Teste de Esforço/métodos , Reprodutibilidade dos Testes , Consumo de Oxigênio/fisiologia , AtletasRESUMO
The impact of training status and sex on intrinsic skeletal muscle mitochondrial respiratory capacity remains unclear. We examined this by analysing human skeletal muscle mitochondrial respiration relative to mitochondrial volume and cristae density across training statuses and sexes. Mitochondrial cristae density was estimated in skeletal muscle biopsies originating from previous independent studies. Participants included females (n = 12) and males (n = 41) across training statuses ranging from untrained (UT, n = 8), recreationally active (RA, n = 9), active-to-elite runners (RUN, n = 27) and cross-country skiers (XC, n = 9). The XC and RUN groups demonstrated higher mitochondrial volume density than the RA and UT groups while all active groups (RA, RUN and XC) displayed higher mass-specific capacity of oxidative phosphorylation (OXPHOS) and mitochondrial cristae density than UT. Differences in OXPHOS diminished between active groups and UT when normalising to mitochondrial volume density and were lost when normalising to muscle cristae surface area density. Moreover, active females (n = 6-9) and males (n = 15-18) did not differ in mitochondrial volume and cristae density, OXPHOS, or when normalising OXPHOS to mitochondrial volume density and muscle cristae surface area density. These findings demonstrate: (1) differences in OXPHOS between active and untrained individuals may be explained by both higher mitochondrial volume and cristae density in active individuals, with no difference in intrinsic mitochondrial respiratory capacity (OXPHOS per muscle cristae surface area density); and (2) no sex differences in mitochondrial volume and cristae density or mass-specific and normalised OXPHOS. This highlights the importance of normalising OXPHOS to muscle cristae surface area density when studying skeletal muscle mitochondrial biology. KEY POINTS: Oxidative phosphorylation is the mitochondrial process by which ATP is produced, governed by the electrochemical gradient across the inner mitochondrial membrane with infoldings named cristae. In human skeletal muscle, the mass-specific capacity of oxidative phosphorylation (OXPHOS) can change independently of shifts in mitochondrial volume density, which may be attributed to variations in cristae density. We demonstrate that differences in skeletal muscle OXPHOS between healthy females and males, ranging from untrained to elite endurance athletes, are matched by differences in cristae density. This suggests that higher OXPHOS in skeletal muscles of active individuals is attributable to an increase in the density of cristae. These findings broaden our understanding of the variability in human skeletal muscle OXPHOS and highlight the significance of cristae, specific to mitochondrial respiration.
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Mitocôndrias Musculares , Músculo Esquelético , Masculino , Feminino , Humanos , Músculo Esquelético/fisiologia , Mitocôndrias Musculares/metabolismo , Fosforilação Oxidativa , Respiração , Membranas MitocondriaisRESUMO
Aerobic and resistance exercise (RE) induce distinct molecular responses. One hypothesis is that these responses are antagonistic and unfavorable for the anabolic response to RE when concurrent exercise is performed. This thesis may also depend on the participants' training status and concurrent exercise order. We measured free-living myofibrillar protein synthesis (MyoPS) rates and associated molecular responses to resistance-only and concurrent exercise (with different exercise orders), before and after training. Moderately active men completed one of three exercise interventions (matched for age, baseline strength, body composition, and aerobic capacity): resistance-only exercise (RE, n = 8), RE plus high-intensity interval exercise (RE+HIIE, n = 8), or HIIE+RE (n = 9). Participants trained 3 days/week for 10 weeks; concurrent sessions were separated by 3 h. On the first day of Weeks 1 and 10, muscle was sampled immediately before and after, and 3 h after each exercise mode and analyzed for molecular markers of MyoPS and muscle glycogen. Additional muscle, sampled pre- and post-training, was used to determine MyoPS using orally administered deuterium oxide (D2 O). In both weeks, MyoPS rates were comparable between groups. Post-exercise changes in proteins reflective of protein synthesis were also similar between groups, though MuRF1 and MAFbx mRNA exhibited some exercise order-dependent responses. In Week 10, exercise-induced changes in MyoPS and some genes (PGC-1É and MuRF1) were dampened from Week 1. Concurrent exercise (in either order) did not compromise the anabolic response to resistance-only exercise, before or after training. MyoPS rates and some molecular responses to exercise are diminished after training.
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Composição Corporal , Exercício Físico , Masculino , Humanos , Tolerância ao Exercício , Glicogênio , MúsculosRESUMO
Cycling time trial (TT) protocols have been shown to be reliable in trained cyclists, but their reproducibility in lesser-trained individuals is unknown. This study examined the reliability of a self-paced 15-minute cycling TT in recreationally active individuals. Twelve recreationally active males (age 27 ± 3 y; body mass 75.2 ± 8.9 kg; VËO2peak = 51.10 ± 7.53 mlâkgâmin-1) completed a VËO2peak test and four experimental trials, separated by > 48 h. Experimental trials consisted of 10 min cycling at 60% Wmax, followed by a self-paced 15-min TT. Heart rate and work done were recorded every 5 min during the TT; and coefficient of variation (CV) was calculated. Work done was not different (P = 0.706) between trials (193.2 ± 45.3 kJ; 193.2 ± 43.5 kJ; 192.0 ± 42.3 kJ; 193.9 ± 42.8 kJ). Within participant CV ranged from 0.5-4.9% for the four TTs, with a mean CV of 2.1%. Mean CV decreased from 2.0% (range 0.1-5.0%) for the first two TTs to 1.7% (range 0.2-5.6%) for the second and third TTs, and further decreased to 1.0% (range 0.2-1.8%) for the third and fourth TTs. In conclusion, the use of a short-duration self-paced cycling TT in recreationally active individuals is a reliable performance measure.
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Ciclismo , Consumo de Oxigênio , Masculino , Humanos , Adulto Jovem , Adulto , Reprodutibilidade dos Testes , Fatores de Tempo , Frequência CardíacaRESUMO
Os cuidados paliativos abrangem intervenções no alívio do sofrimento da pessoa em situação paliativa e família. Para que se possam prestar cuidados paliativos de excelência é necessária uma equipa multiprofissional com competências específica e diferenciadas. Assim, os serviços de saúde estão a fazer uma aposta na formação contínua das suas equipas com o objetivo de contribuir para a qualidade desejada, o que traduzirá a sua idoneidade quer da atividade assistencial quer formativa. Partindo destes pressupostos, dando continuidade ao percurso académico, optou-se por realizar o Estágio de Natureza Profissional na Equipa Comunitária de Suporte em Cuidados Paliativos. O objetivo foi desenvolver competências especializadas na área da enfermagem à pessoa em situação paliativa. Durante o estágio, recorreu-se a metodologias ativas, participativas, investigativas, de gestão e formação. No domínio da investigação, desenvolveu-se um estudo exploratório descritivo sobre as necessidades de formação da equipa de saúde de Cuidados Paliativos, com o intuito de contribuir para a elaboração de um projeto de formação em serviço dando resposta a um dos requisitos de acreditação da idoneidade formativa. A recolha de dados realizou-se por meio de um questionário elaborado ad hoc e submetidos a análise estatística. Os principais resultados revelam que mais de metade da equipe de saúde multidisciplinar apresenta formação diferenciada em CP obtida através de cursos pós-graduação e mestrado. Apresenta carências de formação nas áreas de: Precauções Básicas de Controlo de Infeção, Gestão dos Riscos, Emergências Clínicas, Emergências Não Clínicas, e a equipa identifica necessidade de formação sobre Comunicação em Cuidados Paliativos e Apoios Sociais em Cuidados Paliativos, considera importante a formação contínua em serviço, reconhecendo vantagens, tais como atualização e consolidação de conhecimentos e, melhoria dos cuidados prestados além da aquisição. Apesar das dificuldades identificadas nomeadamente falta de tempo/disponibilidade, a falta de recursos humanos, falta de planeamento da formação infere-se a necessidade premente da existência de um projeto de formação contínua em contexto de prática clínica direcionada às reais necessidades enquanto motor de transformação no cuidar. No domínio da prestação de cuidados de enfermagem à pessoa em situação paliativa, foram desenvolvidas competências especializadas, designadamente ao nível da gestão de sintomas, apoio e acompanhamento à família, apoio no processo de luto, comunicação, trabalho em equipa e habilidades de consultadoria. Foram também adquiridas competências no que se refere à formação, à gestão de cuidados. Salienta-se que, é fundamental o desenvolvimento de competências especializadas em cuidados paliativos para a implementação de intervenções de enfermagem adequadas, efetivas e humanas no cuidar da pessoa em situação paliativa e família.
Palliative care encompasses interventions to relieve the suffering of the palliative care patient and family. In order to provide excellent palliative care, a multiprofessional team with specific and differentiated skills is required. Thus, health services are investing in the continuous training of their teams in order to contribute to the desired quality, which will reflect their suitability both in terms of care and training. Based on these assumptions, continuing the academic path, it was decided to carry out the Professional Internship in the Community Support Team in Palliative Care. The objective was to develop specialized skills in the area of nursing to the person in a palliative situation. During the internship, active, participatory, investigative, management and training methodologies were used. In the field of research, a descriptive exploratory study was developed on the training needs of the Palliative Care health team, with the aim of contributing to the elaboration of an in-service training plan in response to one of the requirements for accreditation of training suitability. Data were collected through an ad hoc questionnaire and submitted to statistical analysis. The main results show that more than half of the multidisciplinary health team has differentiated training in PC obtained through postgraduate and master's courses. It presents training deficiencies in the areas of: Basic Infection Control Precautions, Risk Management, Clinical Emergencies, Non-Clinical Emergencies, and the team identifies a need for training on Communication in Palliative Care and Social Supports in Palliative Care, considers continuous in-service training important, recognizing advantages such as updating and consolidating knowledge and, improving the care provided in addition to acquisition. Despite the difficulties identified, namely lack of time/availability, lack of human resources, lack of training planning, there is a pressing need for a continuous training plan in the context of clinical practice directed to real needs as a driver of transformation in care. In the field of providing nursing care to the person in a palliative situation, specialized skills were developed, namely in terms of symptom management, support and accompaniment to the family, support in the grieving process, communication, teamwork and consulting skills. Skills were also acquired in training, care management. It is emphasized that the development of specialized skills in palliative care is essential for the implementation of appropriate, effective and humane nursing interventions in the care of the person in a palliative situation and family.
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Introduction: Mechanic power output (MPO) and oxygen consumption (VO2) reflect endurance capacity and are often stated relative to body mass (BM) but less often per skeletal muscle mass (SMM). Rating of perceived exertion (RPE) has previously shown conflicting results between sexes at submaximal intensities. Individual body composition, however, largely differs due to sex and training status. It was the aim of this study to evaluate RPE of untrained and trained individuals of both sexes considering body composition and to estimate whether RPE could be improved as a tool to determine endurance capacity. Methods: The study included 34 untrained adults (age 26.18 ± 6.34 years, 18 women) and 29 endurance trained (age 27.86 ± 5.19, 14 women) who were measured for body composition (InBody 770, InBody Europe B.V., Germany) and tested on a treadmill (Pulsar, H/P/Cosmos, Germany) for aerobic capacity (Metalyzer 3B, Cortex Biophysik GmbH, Germany) in an all-out exercise test applying the Bruce-protocol. VO2, MPO, heart rate (HR), and RPE were obtained at each exercise stage. VO2 and MPO were calculated per BM and SMM. RPE values were correlated with absolute VO2 and MPO, as well as relative to BM, and SMM. HR values and the parameters' standardized values served for comparison to standard procedures. Results: VO2 and MPO were higher in men compared to women and in trained compared to untrained participants. No differences between groups and sexes exist when VO2 and MPO were calculated per BM. When calculated per SMM, VO2 and MPO indicate opposite results already at low intensity stages of exercise test. RPE values had highest correlation with MPO per SMM (R2 = 0.8345) compared to absolute MPO (R2 = 0.7609), or MPO per BM (R2 = 0.8176). Agreement between RPE and MPO per SMM was greater than between RPE and HR (p = 0.008). Conclusion: Although RPE represents a subjective value at first glance, it was shown that RPE constitutes a valuable tool to estimate endurance capacity, which can be further enhanced if individual body composition is considered. Furthermore, MPO and VO2 should be considered relative to SMM. These findings might help to avoid over-exertion, especially among untrained people, by adjusting the training intensity for each subject according to the individual strain evaluated in an exercise test based on individual body composition.
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NEW FINDINGS: What is the central question of this study? Are myofibre protein signalling responses to ex vivo dynamic contractions altered by accustomization to voluntary endurance training in rats? What is the main finding and its importance? In response to ex vivo dynamic muscle contractions, canonical myofibre protein signalling pertaining to metabolic transcriptional regulation, as well as translation initiation and elongation, was not influenced by prior accustomization to voluntary endurance training in rats. Accordingly, intrinsic myofibre protein signalling responses to standardized contractile activity may be independent of prior exercise training in rat skeletal muscle. ABSTRACT: Skeletal muscle training status may influence myofibre regulatory protein signalling in response to contractile activity. The current study employed a purpose-designed ex vivo dynamic contractile protocol to evaluate the effect of exercise-accustomization on canonical myofibre protein signalling for metabolic gene expression and for translation initiation and elongation. To this end, rats completed 8 weeks of in vivo voluntary running training versus no running control intervention, whereupon an ex vivo endurance-type dynamic contraction stimulus was conducted in isolated soleus muscle preparations from both intervention groups. Protein signalling response by phosphorylation was evaluated by immunoblotting at 0 and 3 h following ex vivo stimulation. Phosphorylation of AMP-activated protein kinase α-isoforms and its downstream target, acetyl-CoA carboxylase, as well as phosphorylation of eukaryotic elongation factor 2 (eEF2) was increased immediately following the dynamic contraction protocol (at 0 h). Signalling for translation initiation and elongation was evident at 3 h after dynamic contractile activity, as evidenced by increased phosphorylation of p70 S6 kinase and eukaryotic translation initiation factor 4E-binding protein 1, as well as a decrease in phosphorylation of eEF2 back to resting control levels. However, prior exercise training did not alter phosphorylation responses of the investigated signalling proteins. Accordingly, protein signalling responses to standardized endurance-type contractions may be independent of training status in rat muscle during ex vivo conditions. The present findings add to our current understanding of molecular regulatory events responsible for skeletal muscle plasticity.
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Contração Muscular , Transdução de Sinais , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Fator 2 de Elongação de Peptídeos/metabolismo , Fosforilação , Ratos , Transdução de Sinais/fisiologiaRESUMO
Traditional graded exercise testing to assess maximal oxygen uptake (VO2max) may not well represent resistance-trained athletes due to their unfamiliarity with continuous exercise. For this reason, it is possible discontinuous exercise protocols may better represent the maximum capacity for aerobic metabolism in resistance-trained athletes, in order to provide a more valid assessment of VO2max and risk of developing cardiovascular disease. Purpose: The purpose of this experiment was to compare VO2peak during a continuous and discontinuous modified Bruce protocol in both highly resistance-trained and endurance-trained males. Methods: 19 college-aged males (age: 20.6 ± 1.9 yr, height: 176.5 ± 7.6 cm, weight: 85.0 ± 25.6 kg) of intermediate resistance- or endurance-trained status were recruited for this study. Participants completed a continuous and discontinuous modified Bruce protocol on two visits separated by seven days. Results: A 2×2 one-way ANOVA revealed a significant group main effect for VO2peak (p = 0.004) in which endurance athletes achieved significantly higher VO2peak values compared to resistance-trained athletes. A significant group main effect for RPE was found (p = 0.045) in which endurance-trained reported significantly higher RPE values than the resistance-trained. A significant main effect for protocol for heart rate (p = 0.033) was found in which individuals achieved higher heart rates during the continuous protocol compared to the discontinuous. Conclusion: Although a discontinuous protocol with rest periods between stages is comparable to the exercise mode familiar to resistance-trained athletes, it did not provide any additional benefit to VO2peak values.
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The aim of this study was to investigate differences in skeletal muscle gene expression of highly trained endurance and strength athletes in comparison to untrained individuals at rest and in response to either an acute bout of endurance or strength exercise. Endurance (ET, n = 8, VO2max 67 ± 9 mL/kg/min) and strength athletes (ST, n = 8, 5.8 ± 3.0 training years) as well as untrained controls (E-UT and S-UT, each n = 8) performed an acute endurance or strength exercise test. One day before testing (Pre), 30 min (30'Post) and 3 h (180'Post) afterwards, a skeletal muscle biopsy was obtained from the m. vastus lateralis. Skeletal muscle mRNA was isolated and analyzed by Affymetrix-microarray technology. Pathway analyses were performed to evaluate the effects of training status (trained vs. untrained) and exercise mode-specific (ET vs. ST) transcriptional responses. Differences in global skeletal muscle gene expression between trained and untrained were smaller compared to differences in exercise mode. Maximum differences between ET and ST were found between Pre and 180'Post. Pathway analyses showed increased expression of exercise-related genes, such as nuclear transcription factors (NR4A family), metabolism and vascularization (PGC1-α and VEGF-A), and muscle growth/structure (myostatin, IRS1/2 and HIF1-α. The most upregulated genes in response to acute endurance or strength exercise were the NR4A genes (NR4A1, NR4A2, NR4A3). The mode of acute exercise had a significant effect on transcriptional regulation Pre vs. 180'Post. In contrast, the effect of training status on human skeletal muscle gene expression profiles was negligible compared to strength or endurance specialization. The highest variability in gene expression, especially for the NR4A-family, was observed in trained individuals at 180'Post. Assessment of these receptors might be suitable to obtain a deeper understanding of skeletal muscle adaptive processes to develop optimized training strategies.
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Atletas , Regulação da Expressão Gênica/genética , Músculo Esquelético/metabolismo , Resistência Física/genética , Adolescente , Adulto , Teste de Esforço , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Proteínas Substratos do Receptor de Insulina/genética , Masculino , Músculo Esquelético/fisiologia , Miostatina , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Resistência Física/fisiologia , Análise Serial de Proteínas , RNA Mensageiro , Treinamento Resistido , Fator A de Crescimento do Endotélio Vascular/genética , Adulto JovemRESUMO
BACKGROUND: This study compared the muscle activity and six repetition maximum (6-RM) loads in bench press with narrow, medium, and wide grip widths with sub-group comparisons of resistance-trained (RT) and novice-trained (NT) men. METHODS: After two familiarization sessions, twenty-eight subjects lifted their 6-RM loads with the different grip widths with measurement of electromyographic activity. RESULTS: Biceps brachii activity increased with increasing grip width, whereas wide grip displayed lower triceps brachii activation than medium and narrow. In the anterior deltoid, greater activity was observed using a medium compared to narrow grip. Similar muscle activities were observed between the grip widths for the other muscles. For the RT group, greater biceps brachii activity with increasing grip width was observed, but only greater activity was observed in the NT group between narrow and wide. Comparing wide and medium grip width, the RT group showed lower triceps activation using a wide grip, whereas the NT group showed lower anterior deltoid activation using a narrow compared to medium grip. Both groups demonstrated lower 6-RM loads using a narrow grip compared to the other grips. CONCLUSION: Grip widths affect both 6-RM loads and triceps brachii, biceps brachii, and anterior deltoid activity especially between wide and narrow grip widths.
Assuntos
Treinamento Resistido , Levantamento de Peso , Eletromiografia , Força da Mão , Humanos , Masculino , Força Muscular , Músculo EsqueléticoRESUMO
PURPOSE: To assess the value of monitoring changes in fitness in professional soccer players, using changes in heart rate at submaximal intensity (HR12km/h) over the velocity at a lactate concentration of 4 mmol/L (v4mmol/L). The authors reexamined (1) a range of threshold magnitudes, which may improve detecting substantial individual changes and (2) the agreement between changes in these 2 variables. METHODS: On at least 2 occasions during different moments of the season, 97 professional soccer players from Germany (first, second, and fourth division) completed an incremental test to determine HR12km/h and v4mmol/L. Optimal thresholds for changes in HR12km/h and v4mmol/L were assessed, using various methods (eg, smallest worthwhile change + typical error [TE], successive reiterations approach). Agreement between both variable changes was examined for the whole sample (225 comparisons), 4 different subgroups (depending on the moment of the season), and in an individual over 6 years (n = 23 tests). RESULTS: Changes of 4.5% and 6.0% for HR12km/h and v4mmol/L, respectively, were rated as optimal to indicate substantial changes in fitness. Depending on the (sub)groups analyzed, these thresholds yielded 0% to 2% full mismatches, 22% to 38% partial agreements, and 60% to 78% full agreements in terms of fitness change interpretation between both variables. CONCLUSIONS: When lactate sampling during incremental tests is not possible, practitioners willing to monitor adult professional soccer players' (Germany; first, second, and fourth division) training status can confidently implement short, 3-minute submaximal runs, with 4.5% changes in HR12km/h being indicative of true substantial fitness changes, with 60% to 78% accuracy. Future studies should investigate the potential role of confounding factors of HR12km/h to improve changes in fitness prediction.
Assuntos
Aptidão Cardiorrespiratória , Futebol , Adulto , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico , Aptidão Física/fisiologia , Futebol/fisiologiaRESUMO
PURPOSE: To provide a systematic overview of physiological parameters used to determine the training status of a trail runner and how well these parameters correlate with real-world trail running performance. METHOD: An electronic literature search of the PubMed and Scopus digital databases was performed. Combinations of the terms "trail run" or "trail runner" or "trail running" and "performance" were used as search terms. Seven studies met the inclusion criteria. RESULTS: Trail running performance most commonly correlated (mean [SD]) with maximal aerobic capacity (71%; r = -.50 [.32]), lactate threshold (57%; r = -.48 [.28]), velocity at maximal aerobic capacity (43%; r = -.68 [.08]), running economy (43%; r = -.31 [.22]), body fat percentage (43%; r = .55 [.21]), and age (43%; r = .52 [.14]). Regression analyses in 2 studies were based on a single variable predicting 48% to 60% of performance variation, whereas 5 studies included multiple variable regression analyses predicting 48% to 99% of performance variation. CONCLUSIONS: Trail running performance is multifaceted. The classic endurance model shows a weaker association with performance in trail running than in road running. Certain variables associated with trail running research (such as testing procedures, race profiles, and study participants) hinder the execution of comparative studies. Future research should employ trail-specific testing protocols and clear, objective descriptions of both the race profile and participants' training status.
Assuntos
Corrida , Humanos , Consumo de Oxigênio , Resistência FísicaRESUMO
An attenuated ability to appropriately oxidize fat (metabolic inflexibility) has been associated with the development of obesity and type 2 diabetes. Previous studies have found that regular exercise training increases the body's ability to oxidize fat during exercise, but also shown that fat oxidation at the same relative and absolute exercise intensity is lower in old compared with young adults. Based on these studies we investigated the effect of training status on the whole-body peak fat oxidation rate (PFO) during exercise in young and middle-aged trained and untrained men. We hypothesized that aging was associated with decreased PFO, but regular exercise training could counteract this decline. 36 healthy non-overweight young and middle-aged men were recruited into a four groups: young (27 [24-30] yrs, (Mean [95% CI])) untrained (â©O2peak: 47 [44-49] ml/min/kg), young (28 [26-30] yrs) trained (â©O2peak: 64 [62-67] ml/min/kg), middle-aged (55 [53-57] yrs) untrained (â©O2peak: 37 [32-42] ml/min/kg) and middle-aged (54 [51-57] yrs) trained (â©O2peak: 55 [51-58] ml/min/kg). PFO was measured by indirect calorimetry while subjects performed a validated incremental exercise protocol on a cycle ergometer. Whole-body peak fat oxidation rate was higher in the young trained compared to young untrained subjects (0.70 [0.65-0.75] vs.0.45 [0.36-0.54] g/min, post-hoc: p < 0.001); however, this training effect was attenuated in middle-aged trained and untrained subjects (0.44 [0.38-0.50] vs. 0.41 [0.35-0.47] g/min, post-hoc: p = 0.83, respectively). In summary, these findings suggest that the training induced effects on whole-body fat oxidation found in young men may be attenuated in middle-aged men.
Assuntos
Envelhecimento/fisiologia , Exercício Físico/fisiologia , Metabolismo dos Lipídeos/fisiologia , Consumo de Oxigênio/fisiologia , Adulto , Fatores Etários , Análise de Variância , Composição Corporal/fisiologia , Dióxido de Carbono/metabolismo , Estudos Transversais , Humanos , Masculino , Pessoa de Meia-Idade , OxirreduçãoRESUMO
The number of children and adolescents with mental disorders in China is increasing year by year, but the child and adolescent psychiatrists (CAPs) remain very scarce. So far, there is only a national psychiatrist certification system, and no child and adolescent psychiatrist certification system. Instead, the psychiatrist can receive the post-graduation training certificate or nationally approved Ph.D. and Master's degree training certificate for becoming a CAP. Currently, studies on the training status of CAPs in China are unavailable. This study investigated the current training status of CAPs in China intending to improve the relevant training programs. Self-developed questionnaires were distributed to 28 Executive Committee members of Chinese Society of Child and Adolescent Psychiatry from 32 training hospitals which Nationally approved Ph.D. and Master's degree training base for child and adolescent psychiatry or post-graduation training (Intern and Fellow) base for child and adolescent psychiatry in 14 provinces and municipalities for collecting necessary information of the respondents, and evaluation of current education and training. Using the descriptive analysis for statistical analysis to understand the current training status of child psychiatrists in China. A total of 28 valid questionnaires were returned. The training units were concentrated in large- and medium-sized cities. Moreover, the current medical personnel in China for diagnosing and treatment of children and adolescents with mental disorders was small in number with fixed learning modes. For the training of CAPs, the scientific basis of the training content, as well as the practicality of the training content, and the ability to solve problems, are not sufficient. Furthermore, the effects of current educational training of CAPs regarding teaching and professional, scientific research abilities remained relatively weak. Therefore, it is necessary to focus on training comprehensive qualities and abilities, such as the spirit of dedication. Currently, physicians who have received post-graduate training or Ph.D. and Master's degree training in child and adolescent psychiatry in China are very scarce. Although CAPs have a long history of training, post-graduate, or doctoral master's degree training is mainly a training method. And, the national specialized certification system for CAPs pilot in major cities. The training system of CAPs should be further improved in the future, and the number of CAPs should be increased.