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Short sprints are predominantly assessed using timing gates and analyzed through parameters of the mono-exponential equation, including estimated maximal sprinting speed (MSS) and relative acceleration (TAU), derived maximum acceleration (MAC), and relative propulsive maximal power (PMAX), further referred to as the No Correction model. However, the frequently recommended flying start technique introduces a bias during parameter estimation. To correct this, two additional models (Estimated TC and Estimated FD) were proposed. To estimate model precision and sensitivity to detect the change, 31 basketball players executed multiple 30 m sprints. Athlete performance was simultaneously measured by a laser gun and timing gates positioned at 5, 10, 20, and 30 m. Short sprint parameters were estimated using a laser gun, representing the criterion measure, and five different timing gate models, representing the practical measures. Only the MSS parameter demonstrated a high agreement between the laser gun and timing gate models, using the percent mean absolute difference (%MAD) estimator (%MAD < 10%). The MSS parameter also showed the highest sensitivity, using the minimum detectable change estimator (%MDC95), with an estimated %MDC95 < 17%. Interestingly, sensitivity was the highest for the No Correction model (%MDC95 < 7%). All other parameters and models demonstrated an unsatisfying level of sensitivity. Thus, sports practitioners should be cautious when using timing gates to estimate maximum acceleration indices and changes in their respective levels.
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Aceleração , Desempenho Atlético , Corrida , Humanos , Corrida/fisiologia , Desempenho Atlético/fisiologia , Masculino , Adulto Jovem , Adulto , Basquetebol/fisiologia , AtletasRESUMO
Lifecourse nutrition encompasses nourishment from early development into parenthood. From preconception and pregnancy to childhood, late adolescence, and reproductive years, life course nutrition explores links between dietary exposures and health outcomes in current and future generations from a public health perspective, usually addressing lifestyle behaviours, reproductive well-being and maternal-child health strategies. However, nutritional factors that play a role in conceiving and sustaining new life might also require a molecular perspective and recognition of critical interactions between specific nutrients and relevant biochemical pathways. The present perspective summarises evidence about the links between diet during periconception and next-generation health and outlines the main metabolic networks involved in nutritional biology of this sensitive time frame.
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Acontecimentos que Mudam a Vida , Estado Nutricional , Gravidez , Feminino , Adolescente , Humanos , Criança , Dieta , Nutrientes , Redes e Vias MetabólicasRESUMO
Endurance training-induced changes in left ventricular diastolic function and right ventricular parameters have been investigated extensively in adolescent athletes. Our aim was to examine the parameters for adolescent athletes (n=121, 15.1±1.6 years) compared to adult athletes and age-matched non-athletes. We explored the effects of influencing factors on the echocardiographic parameters. Significantly higher E/A (p<0.05) and e' values (p<0.001) were detected in adolescent athletes compared to age-matched non-athletes' and also adult athletes' parameters. Significantly lower structural and functional right ventricular parameters (p<0.05) were detected in adult athletes. In adolescent athletes significantly higher right ventricular diameters, tricuspid S wave, right ventricular end-diastolic and end-systolic area values (p<0.05) were found compared to the matching parameters of non-athletes. We found significantly higher corrected tricuspid annular plane systolic excursion values (p<0.001) in athletes compared to the non-athletes. Based on multivariate analysis lean body mass, body surface area, age and cumulative training time were proved as strong predictive factors of both left ventricular diastolic and right ventricular parameters. Supernormal left ventricular diastolic function and significantly higher right ventricular parameters are indicative of cardiac adaptation. Well-defined cut-off values should be applied to discriminate pathological conditions in the relation of the influencing factors.
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Atletas , Treino Aeróbico , Função Ventricular Esquerda , Função Ventricular Direita , Adaptação Fisiológica , Adolescente , Adulto , Ecocardiografia , HumanosRESUMO
We analysed the effects of an experimental novel protocol of intensive hydrotherapy with hydrogen-rich water (HRW) on injury recovery in athletic men who suffered an acute ankle sprain (AAS) and compared it with a RICE protocol (rest, ice, compression, elevation). Professional athletes (age 23.7 ± 4.0 years; weight 78.6 ± 5.7 kg, height 182.5 ± 4.3 cm; professional experience 5.9 ± 3.9 years) who incurred AAS during a sport-related activity were randomly assigned immediately after the injury to either hydrogen group (n = 9) or a conventional RICE treatment group (n = 9). Hydrogen group received six 30-min ankle baths with HRW throughout the first 24 h post-injury, with hydrotherapy administered every 4 hours during the intervention period. RICE group stood off the injured leg, with ice packs administered for 20 min every 3 hours, with the injured ankle compressed with an elastic bandage for 24 hours and elevated at all possible times above the level of the heart. HRW was equivalent to RICE protocol to reduce ankle swelling (2.1 ± 0.9% vs. 1.6 ± 0.8%; P = 0.26), range of motion (2.4 ± 1.3 cm vs. 2.7 ± 0.8 cm; P = 0.60), and single-leg balance with eyes opened (18.4 ± 8.2 sec vs. 10.7 ± 8.0 sec; P = 0.06) and closed (5.6 ± 8.4 sec vs. 3.9 ± 4.2 sec; P = 0.59). This non-inferiority pilot trial supports the use of HRW as an effective choice in AAS management. However, more studies are needed to corroborate these findings in other soft tissue injuries.
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Traumatismos do Tornozelo/terapia , Traumatismos em Atletas/terapia , Bandagens Compressivas , Crioterapia/métodos , Hidrogênio/uso terapêutico , Hidroterapia/métodos , Entorses e Distensões/terapia , Adulto , Biomarcadores/sangue , Humanos , Masculino , Medição da Dor , Projetos Piloto , Equilíbrio Postural , Amplitude de Movimento Articular , Adulto JovemRESUMO
Guanidinoacetic acid (GAA, also known as glycocyamine or betacyamine) is a naturally-occurring derivative of glycine and a direct metabolic precursor of creatine, a key player in high-phosphate cellular bioenergetics. GAA is found in human serum and urine, with circulating GAA likely reflects an equilibrium between its endogenous production and utilization/excretion. GAA deficiency (as indicated by low serum GAA) has been reported in various conditions yet this intriguing clinical entity appears to be poorly characterized as yet, either as a primary deficit or a sequel of secondary disease. This minireview article summarizes the inherited and acquired disorders with apparent GAA deficiency and discusses a possible relevance of GAA shortfall in clinical medicine.
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Glicina/análogos & derivados , Doenças Metabólicas/etiologia , Creatina/metabolismo , Metabolismo Energético , Glicina/sangue , Glicina/deficiência , Glicina/metabolismo , Glicina/urina , Humanos , Doenças Metabólicas/sangue , Doenças Metabólicas/metabolismo , Doenças Metabólicas/urinaRESUMO
In this randomized, double-blind, placebo-controlled, crossover pilot trial, we evaluated the effects of 7-day H2 inhalation on exercise performance outcomes and serum hormonal and inflammation profiles in a cohort of young men and women. All participants (age 22.9 ± 1.5 years; body mass index 23.4 ± 2.5 kg m-2; 10 women and 10 men) were allocated to receive either gaseous hydrogen (4%) or placebo (room air) by 20-min once-per-day inhalation for 7 days, with a wash-out period of 7 days to prevent the residual effects of interventions across study periods. The primary treatment outcome was the change in running time-to-exhaustion in the incremental maximal test from baseline to day 7. Additionally, assessment of other exercise performance endpoints and clinical chemistry biomarkers was performed at baseline and at 7 days after each intervention. The trial was registered at ClinicalTrials.gov (ID NCT03846141). Breathing 4% hydrogen for 20 min per day resulted in increased peak running velocity (by up to 4.2%) as compared to air inhalation (P = 0.05). Hydrogen inhalation resulted in a notable drop in serum insulin-like growth factor 1 (IGF-1) by 48.2 ng/mL at follow-up (95% confidence interval [CI]: from -186.7 to 89.3) (P < 0.05), while IGF-1 levels were elevated by 59.3 ng/mL after placebo intervention (95% CI; from -110.7 to 229.5) (P < 0.05). Inhalational hydrogen appears to show ergogenic properties in healthy men and women. Gaseous H2 should be further evaluated for its efficacy and safety in an athletic environment.
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OBJECTIVE: This study aimed to determine the effect of single-bout exercise on aortic stiffness parameters in young basketball players. METHOD AND RESULTS: A total of 108 young male subjects (mean age 14.2 ± 3.4 years) were enrolled into the study. Simultaneous measure- ment of aortic pulse wave velocity (PWVao) and augmentation index (Alxao) were performed with the oscillometric, occlusive device. Echocardiographic parameters of left ventricular systolic and diastolic function at rest were also measured in sportsmen. We did not find significant differences of resting PWVao in comparison with young sportsmen (S) and age-matched healthy volunteers (V): 5.82 ± 0.14 m/s vs 5.83 ± 0.12 m/s for S and V groups, respectively. The values of PWVao measured after dynamic exercise, isometric exercise, and rest were 8.0 ± 0.5 m/s, 5.86 ± 0.1 m/s and 5.82 ± 0.1 m/s, respectively. We confirmed that values after dynamic exercise are significantly different from those after isometric exercise (P < 0.01) and those after rest (P < 0.01). The Alxao values exhibited a considerable, but statistically non-significant, decrease during dynamic exercise in the three groups (11.7 ± 7% vs 3.8 ± 3% vs- 0.9 ± 0.9% for groups 1, 2, and 3, respectively). CONCLUSION: We applied a feasible, clinically useful method which allowed us to measure changes in aortic PWV and Alx during acute, single-bout exercise on the basketball court in young sportsmen.
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Atletas , Exercício Físico/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Esportes/fisiologia , Rigidez Vascular/fisiologia , Função Ventricular Esquerda/fisiologia , Adolescente , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Criança , Ecocardiografia , Humanos , Masculino , Análise de Onda de PulsoRESUMO
Considering the importance of body composition and lower-body strength and power for basketball players' on-court performance, as well as a lack of sports science research focused on female athletes, the purpose of the present investigation was to record the anthropometric and countermovement vertical jump (CMJ) characteristics of top-tier U16 and U18 female basketball players and examine between-group differences in the aforementioned tests. Thirty-two athletes who were a part of the national basketball academy volunteered to participate in the present investigation. Following the body composition assessment conducted via a segmental multifrequency bioimpedance analyzer, athletes performed three CMJs while standing on a force plate system sampling at 1000â Hz. Independent t-test and Mann-Whitney U-test were used to examine between-group differences. The findings reveal significant differences in body composition and lower-body neuromuscular performance characteristics between female basketball players ages 16 and 18. Although no differences were observed in muscle and body fat percentages, the U18 group had significantly greater height, overall body mass (both muscle and fat mass), as well as greater segmental fat-free mass (trunk, both legs and arms), intracellular and extracellular water, and body mass index when compared to their U16 counterparts. On the other hand, the U18 group demonstrated longer eccentric, concentric, and braking phase duration, as well as overall contraction time when compared to the U16 players. In addition, the U18 athletes exhibited higher eccentric mean force and power, concentric impulse, peak power, and mean and peak force.
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Preliminary studies demonstrated beneficial effects of dietary creatine across different post-viral fatigue syndromes. Creatine is often co-administered with glucose to improve its potency yet whether glucose boost the efficacy of creatine in long COVID remains currently unknown. In this report, we investigate the effects of 8-wk creatine intake with and without glucose on patient-reported outcomes, exercise tolerance, and tissue creatine levels in patients with long COVID. Fifteen male and female long COVID adult patients (age 39.7±16.0 y; 9 women) with moderate fatigue and at least one of additional long COVID-related symptoms volunteered to participate in this randomized controlled parallel-group interventional trial. All patients were allocated in a double-blind parallel-group design (1 : 1 : 1) to receive creatine (8 g of creatine monohydrate per day), a mixture of creatine and glucose (8 g of creatine monohydrate and 3 g of glucose per day), or placebo (3 g of glucose per day) t.i.d. during an 8-wk intervention interval. Two-way ANOVA with repeated measures (treatment vs. time interaction) revealed significant differences in changes in total creatine levels between the groups, showing an interaction effect at two brain locations (right precentral white matter F=34.740, p=0.008; partial η2=0.72; left paracentral grey matter F=19.243, p=0.019; partial η2=0.88), with creatine and creatine-glucose outcompeted placebo to elevate creatine levels at these two locations. Several long COVID symptoms (including body aches, breathing problems, difficulties concentrating, headache, and general malaise) were significantly reduced in creatine-glucose group at 8-wk follow-up (p≤0.05); the effect sizes for reducing body aches, difficulties concentrating, and headache were 1.33, 0.80, and 1.12, respectively, suggesting a large effect of creatine-glucose mixture for these outcomes. Our preliminary findings suggest that supplying exogenous creatine with glucose could be recommended as an effective procedure in replenishing brain creatine pool and alleviating long COVID features in this prevalent condition.
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COVID-19 , Creatina , Suplementos Nutricionais , Glucose , Humanos , Creatina/administração & dosagem , Masculino , Feminino , Método Duplo-Cego , Adulto , Glucose/administração & dosagem , Pessoa de Meia-Idade , COVID-19/complicações , SARS-CoV-2 , Fadiga/tratamento farmacológico , Síndrome de COVID-19 Pós-Aguda , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Resultado do TratamentoRESUMO
Guanidinoacetic acid (GAA, also known as glycocyamine or guanidinoacetate) is a naturally occurring alpha amino acid derivative and newly recognized dietary compound obtainable by different foods and nutritional supplements. Anecdotal evidence suggests that the GAA exposure from supplements might be a major source of GAA supply, out-competing other food sources for several orders of magnitude. This original technical paper summarizes information about GAA levels in different nutritional supplements, as derived from the U.S. National Institutes of Health dietary supplement database.
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Under pathological conditions and excessive stress, mitochondria may experience a severe and irreversible loss of function. Both strenuous exhaustive exercise and neurodegenerative disorders appear to share defects in mitochondrial function that may fiercely disrupt the integrity and homeostasis of the organelle, leading to perennial pathological substrates. Here, we overview similarities of mitochondrial dysfunction in two conditions and discuss possible areas of interdisciplinary collaboration and research translation between sports medicine and neurology.
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Atletas , Mitocôndrias/patologia , Doenças Neurodegenerativas/patologia , Exercício Físico , Humanos , Mitocôndrias/metabolismo , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/fisiopatologia , Espécies Reativas de Oxigênio/metabolismo , Medicina Esportiva/métodosRESUMO
INTRODUCTION: The main aim of this pilot study was to examine the effects of a single-dose intervention with a novel nitrate-producing formulation (MagNOVOx™) on biomarkers of cardiorespiratory endurance and muscular fitness in 12 healthy men. METHODS: The study participants (age = 22.7 ± 2.8 years, height = 184.1 ± 5.7 cm, and weight = 82.5 ± 8.4 kg) were randomly allocated to receive either a single dose of MagNOVOx™ or a placebo (inulin) in a cross-over design. The primary outcome for this study was the change in running time to exhaustion evaluated at baseline (before supplementation) and post-intervention. RESULTS: Time to exhaustion was improved after the intervention in 8 out of 11 participants (72.7%) who received MagNOVOx™, and in 1 out of 11 participants (9.1%) who received placebo (p = 0.004), and MagNOVOx™ outcompeted placebo in terms of improving leg press performance (p < 0.01). No significant differences between MagNOVOx™ and placebo were found for blood pressure responses (p > 0.05). CONCLUSION: These promising findings should be further corroborated in medium- and long-term trials, and different populations, while the exact mechanism of MagNOVOx™ requires additional physiological studies.
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OBJECTIVE: The measurement of aortic pulse wave velocity (PWV(ao)) is an accepted marker in stratifying individual cardiovascular risk in adults. There is an increasing volume of evidence concerning impaired vascular function in different diseases in paediatric populations, but, unfortunately, only a few studies are available on the measurement of normal PWV(ao) values in children. The aim of our study was to determine the reference values of PWV(ao) in a large healthy population using a newly developed technique. METHODS: Three thousand, three hundred and seventy-four healthy individuals (1802 boys) aged 3-18 years were examined by an invasively validated, occlusive, oscillometric device. RESULTS: The mean PWV(ao) values increased from 5.5 ± 0.3 to 6.5 ± 0.3 m/s (P < 0.05) in boys and from 5.6 ± 0.3 to 6.4 ± 0.3 m/s (P < 0.05) in girls. The increase, however, was not constant, and the values exhibited a flat period between the ages of 3 and 8 years in both sexes. The first pronounced increase occurred at the age of 12.1 years in boys and 10.4 years in girls. Moreover, between the ages of 3 and 8 years, the brachial SBP and mean blood pressures increased continuously and gradually, whereas the PWV(ao) remained unchanged. By contrast, beyond the age of 9 years, blood pressure and aortic stiffness trends basically moved together. CONCLUSION: Our study provides the largest database to date concerning arterial stiffness in healthy children and adolescents between the ages of 3 and 18 years, and the technology adopted proved easy to use in large paediatric populations, even at a very young age.