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To develop a statistical model of winning times for international swimming events with the aim of predicting winning time distributions and the probability of winning for the 2020 and 2024 Olympic Games. The data set included first and third place times from all individual swimming events from the Olympics and World Championships from 1990 to 2019. We compared different model formulations fitted with Bayesian inference to obtain predictive distributions; comparisons were based on mean percentage error in out-of-sample predictions of Olympics and World Championships winning swim times from 2011 to 2019. The Bayesian time series regression model, comprising auto-regressive and moving average terms and other predictors, had the smallest mean prediction error of 0.57% (CI 0.46-0.74%). For context, using the respective previous Olympics or World Championships winning time resulted in a mean prediction error of 0.70% (CI 0.59-0.82%). The Olympics were on average 0.5% (CI 0.3-0.7%) faster than World Championships over the study period. The model computes the posterior predictive distribution, which allows coaches and athletes to evaluate the probability of winning given an individual's swim time, and the probability of being faster or slower than the previous winning time or even the world record.
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Comportamento Competitivo , Natação , Atletas , Teorema de Bayes , Humanos , Fatores de TempoRESUMO
ABSTRACT: Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res 36(8): 2176-2185, 2022-This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise. Twenty-one recreationally trained subjects (12 men and 9 women) performed a 3-week familiarization phase and were then randomized into one of two 8-week upper-body and lower-body split programs occurring over 3 and then progressing to 4 sessions per week. Subjects performed 4 sets of 5 repetitions at 85% one repetition maximum (1RM) using a traditional-set structure (TRAD, n = 10), which involved 5 minutes of interset rest only, or a cluster-set structure, which included 30-second inter-repetition rest and 3 minutes of interset rest (CLUS, n = 11). A 1RM bench press, repetitions to failure at 70% 1RM, regional muscle thickness, and dual-energy x-ray absorptiometry were used to estimate changes in muscular strength, local muscular endurance, regional muscular hypertrophy, and body composition, respectively. Velocity loss was assessed using a linear position transducer at the intervention midpoint. TRAD demonstrated a significantly greater velocity loss magnitude (g = 1.50) and muscle thickness of the proximal pectoralis major (g = -0.34) compared with CLUS. There were no significant differences between groups for the remaining outcomes, although a small effect size favoring TRAD was observed for the middle region of the pectoralis major (g = -0.25). It seems that the greater velocity losses during sets observed in traditional-set compared with cluster-set structures may promote superior muscular hypertrophy within specific regions of the pectoralis major in recreationally trained subjects.
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Músculo Esquelético , Treinamento Resistido , Composição Corporal , Feminino , Humanos , Hipertrofia , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiologiaRESUMO
Nutrition education programmes for athletes aim to enhance nutrition knowledge and more importantly support positive dietary change to enhance performance, health and well-being. This systematic review assessed changes in the dietary intakes of athletes in response to nutrition education programmes. A search was conducted which included studies providing quantitative dietary intake assessment of athletes of any calibre aged between 12 and 65 years in response to a nutrition education programme. Standardised differences (effect sizes) were calculated (when possible) for each dietary parameter. The search yielded 6285 papers with twenty-two studies (974 participants (71·9 % female)) eligible for inclusion. Studies described athletes competing at high school (n 3) through to college level or higher (n 19). Study designs were either single arm with an intervention-only group (twelve studies; n 241) or double arm including an intervention and control group (ten studies; n 689). No control groups received an alternative or 'sham' intervention. Face-to-face lectures (9/22) and individual nutrition counselling (6/22) were the most common education interventions. Non-weighed, 3-d diet records (10/22) were the most frequently utilised dietary assessment method. Although 14/22 studies (n 5 single and n 9 double) reported significant change in at least one nutrition parameter, dietary changes were inconsistent. Poor study quality and heterogeneity of methods prohibit firm conclusions regarding overall intervention success or superior types of educational modalities. Of note, carbohydrate intakes 'post-intervention' when assessed often failed to meet recommended guidelines (12/17 studies). Given the substantial investment made in nutrition education interventions with athletes, there is a need for well-designed and rigorous research to inform future best practice.
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Atletas , Dieta , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , Ciências da Nutrição e do Esporte/educação , Adolescente , Adulto , Idoso , Criança , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Ingestão de Alimentos , Ingestão de Energia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação Nutricional , Adulto JovemRESUMO
AIM: Waist circumference-to-height ratio (WHt) has been proposed as an alternative measure to BMI due to its focus on central weight distribution and its basic threshold for increased cardiometabolic risk. This study aimed to compare prevalence of overweight including obesity using BMI and WHt, and assess 10-year trends of WHt prevalence, in a representative sample of Irish children. METHODS: Children measured during rounds 2-5 of the Childhood Obesity Surveillance Initiative (n = 20037) were classified as healthy weight or overweight including obesity (International Obesity Task Force age and sex BMI cut-offs), and low or high WHt (WHt ≥ 0.5). Differences in prevalence of BMI and WHt classifications were determined for round five in younger (<9 years) and older (≥9 years) children. The prevalence of high WHt was assessed across rounds. RESULTS: Differences in prevalence between overweight including obesity and high WHt were apparent in younger (BMI: 16.7%, WHt: 8.9%; p < .001) and older (BMI: 21.3%, WHt: 12.1%; p < .001) children. An inverse trend for prevalence of high WHt was identified across rounds (p < .001). CONCLUSION: BMI overestimates overweight including obesity prevalence compared to WHt. Given its ease of use, consideration of the WHt as an additional measure in childhood surveillance and screening is warranted.
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Obesidade Infantil , Razão Cintura-Estatura , Índice de Massa Corporal , Criança , Estudos Transversais , Humanos , Sobrepeso , Obesidade Infantil/diagnóstico , Obesidade Infantil/epidemiologia , Prevalência , Circunferência da CinturaRESUMO
ABSTRACT: Davies, TB, Halaki, M, Orr, R, Mitchell, L, Helms, ER, Clarke, J, and Hackett, DA. Effect of set structure on upper-body muscular hypertrophy and performance in recreationally trained men and women. J Strength Cond Res XX(X): 000-000, 2021-This study explored the effect of volume-equated traditional-set and cluster-set structures on muscular hypertrophy and performance after high-load resistance training manipulating the bench press exercise. Twenty-one recreationally trained subjects (12 men and 9 women) performed a 3-week familiarization phase and were then randomized into one of two 8-week upper-body and lower-body split programs occurring over 3 and then progressing to 4 sessions per week. Subjects performed 4 sets of 5 repetitions at 85% one repetition maximum (1RM) using a traditional-set structure (TRAD, n = 10), which involved 5 minutes of interset rest only, or a cluster-set structure, which included 30-second inter-repetition rest and 3 minutes of interset rest (CLUS, n = 11). A 1RM bench press, repetitions to failure at 70% 1RM, regional muscle thickness, and dual-energy x-ray absorptiometry were used to estimate changes in muscular strength, local muscular endurance, regional muscular hypertrophy, and body composition, respectively. Velocity loss was assessed using a linear position transducer at the intervention midpoint. TRAD demonstrated a significantly greater velocity loss magnitude (g = 1.50) and muscle thickness of the proximal pectoralis major (g = -0.34) compared with CLUS. There were no significant differences between groups for the remaining outcomes, although a small effect size favoring TRAD was observed for the middle region of the pectoralis major (g = -0.25). It seems that the greater velocity losses during sets observed in traditional-set compared with cluster-set structures may promote superior muscular hypertrophy within specific regions of the pectoralis major in recreationally trained subjects.
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This exploratory clinical case report presents an 87-year-old man who began bodybuilding at the age of 76 years and was officially recognised as the world's oldest competitive bodybuilder, competing until age 83. He has a background of complex health conditions including polio, strokes, cardiac arrest, atrial fibrillation, prostate disease, osteoarthritis, depression, bowel obstruction, reflux, and bladder cancer. Assessments of body composition, bone density, muscle performance, and diet-related practices were performed. The bodybuilder had superior fat-free mass, lower fat mass, and generally greater muscle performance compared to untrained healthy males of a similar age. Commencement of bodybuilding in older age appears to be possible, even with ongoing complex health conditions, and the potential benefits of this practice require systematic investigation in the future.
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Composição Corporal , Somatotipos , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Humanos , Masculino , Força MuscularRESUMO
Body composition can substantially impact elite swimming performance. In practice, changes in fat and lean mass of elite swimmers are estimated using body mass, sum of seven skinfolds (∑7) and lean mass index (LMI). However, LMI may be insufficiently accurate to detect small changes in body composition which could meaningfully impact swimming performance. This study developed equations which estimate dual-energy x-ray absorptiometry (DXA)-derived lean and fat mass using body mass and ∑7 data. Elite Australian swimmers (n = 44; 18 male, 26 female) completed a DXA scan and standardised body mass and ∑7 measurements. Equations to estimate DXA-derived lean and fat mass based on body mass, ∑7 and sex were developed. The relationships between ∑7, body mass and DXA-derived lean and fat mass were non-linear. Fat mass (Adjusted R2 = 0.91; standard error = 1.0 kg) and lean mass (Adjusted R2 = 0.99; standard error = 1.0 kg) equations were considered sufficiently accurate. Lean mass estimates outperformed the LMI in identifying the correct direction of change in lean mass (82% correct; LMI 71%). Using the accurate estimations produced by these equations will enhance the prescription and evaluation of programmes to optimise the body composition and subsequent performance in swimmers.
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Distribuição da Gordura Corporal/estatística & dados numéricos , Índice de Massa Corporal , Dobras Cutâneas , Natação/fisiologia , Absorciometria de Fóton , Adolescente , Adulto , Desempenho Atlético/fisiologia , Austrália , Feminino , Humanos , Masculino , Análise de Regressão , Adulto JovemRESUMO
Amirthalingam, T, Mavros, Y, Wilson, GC, Clarke, JL, Mitchell, L, and Hackett, DA. Effects of a modified German volume training program on muscular hypertrophy and strength. J Strength Cond Res 31(11): 3109-3119, 2017-German Volume Training (GVT), or the 10 sets method, has been used for decades by weightlifters to increase muscle mass. To date, no study has directly examined the training adaptations after GVT. The purpose of this study was to investigate the effect of a modified GVT intervention on muscular hypertrophy and strength. Nineteen healthy men were randomly assign to 6 weeks of 10 or 5 sets of 10 repetitions for specific compound resistance exercises included in a split routine performed 3 times per week. Total and regional lean body mass, muscle thickness, and muscle strength were measured before and after the training program. Across groups, there were significant increases in lean body mass measures, however, greater increases in trunk (p = 0.043; effect size [ES] = -0.21) and arm (p = 0.083; ES = -0.25) lean body mass favored the 5-SET group. No significant increases were found for leg lean body mass or measures of muscle thickness across groups. Significant increases were found across groups for muscular strength, with greater increases in the 5-SET group for bench press (p = 0.014; ES = -0.43) and lat pull-down (p = 0.003; ES = -0.54). It seems that the modified GVT program is no more effective than performing 5 sets per exercise for increasing muscle hypertrophy and strength. To maximize hypertrophic training effects, it is recommended that 4-6 sets per exercise be performed, as it seems gains will plateau beyond this set range and may even regress due to overtraining.
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Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Levantamento de Peso/fisiologia , Adaptação Fisiológica , Composição Corporal , Humanos , Hipertrofia , Masculino , Medicina Esportiva , Tronco/fisiologia , Adulto JovemRESUMO
BACKGROUND: Nutrition guidance for athletes must consider a range of variables to effectively support individuals in meeting energy and nutrient needs. Resistance exercise is a widely adopted training method in athlete preparation and rehabilitation and therefore is one such variable that will influence nutrition guidance. Given its prominence, the capacity to meaningfully quantify resistance exercise energy expenditure will assist practitioners and researchers in providing nutrition guidance. However, the significant contribution of anaerobic metabolism makes quantifying energy expenditure of resistance exercise challenging. OBJECTIVE: The aim of this scoping review was to investigate the methods used to assess resistance exercise energy expenditure. METHODS: A literature search of Medline, SPORTDiscus, CINAHL and Web of Science identified studies that included an assessment of resistance exercise energy expenditure. Quality appraisal of included studies was performed using the Rosendal Scale. RESULTS: A total of 19,867 studies were identified, with 166 included after screening. Methods to assess energy expenditure included indirect calorimetry (n = 136), blood lactate analysis (n = 25), wearable monitors (n = 31) and metabolic equivalents (n = 4). Post-exercise energy expenditure was measured in 76 studies. The reported energy expenditure values varied widely between studies. CONCLUSIONS: Indirect calorimetry is widely used to estimate energy expenditure. However, given its limitations in quantifying glycolytic contribution, indirect calorimetry during and immediately following exercise combined with measures of blood lactate are likely required to better quantify total energy expenditure. Due to the cumbersome equipment and technical expertise required, though, along with the physical restrictions the equipment places on participants performing particular resistance exercises, indirect calorimetry is likely impractical for use outside of the laboratory setting, where metabolic equivalents may be a more appropriate method.
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CONTEXT: Optimizing nutrition in military groups through improved diet quality and nutrition knowledge is key in supporting the high physical and cognitive demands. OBJECTIVE: The objective of this investigation was to systematically review the effectiveness of nutrition interventions among military personnel in improving diet quality and/or nutrition knowledge. DATA SOURCES: Medline, Embase, CINAHL, and Scopus were searched from the earliest records to May 2020. DATA EXTRACTION: Data were extracted by 2 reviewers. The primary outcomes were diet quality and/or nutrition knowledge. DATA ANALYSIS: Twenty studies were included. The main intervention approaches identified were nutrition education of individuals (i.e., education-based studies; EB) (n = 12), and manipulation of the food service environment (i.e., dining facility studies; DFACs) (n = 8). The most common strategies were face-to-face lectures (n = 8) for EB, and healthier menus (n = 7) and education of catering staff (n = 6) for DFAC interventions. Most studies (18/20) demonstrated favorable within-group effects; however, dietary changes were inconsistent. Five of 10 studies using a comparator group demonstrated positive between-group differences. CONCLUSION: Although potential exists for improving diet quality and nutrition knowledge in military populations, the heterogeneity of the studies to date limits conclusions on the most efficacious strategies.
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Serviços de Alimentação , Militares , Dieta , Educação em Saúde , Humanos , Estado NutricionalRESUMO
Dietary intake plays a significant role in athletic performance and is influenced by several factors, including nutrition knowledge. Gaelic footballers are amateur athletes who conduct high-intensity, intermittent activity during training and competition, and have previously demonstrated insufficient dietary intake. This study aimed to examine nutrition knowledge in elite and non-elite Gaelic footballers. An online survey was distributed to competitive Gaelic footballers, examining nutrition knowledge using the Abridged Nutrition for Sport Knowledge Questionnaire. Total, general, and sport nutrition knowledge were compared between elite and non-elite athletes, and those who had and had not previously received nutrition education, using Mann-Whitney U-tests. A total of 190 participants (15.3% women) completed the survey. No differences between elite and non-elite athletes in nutrition knowledge were identified (p > 0.05). Athletes with previous nutrition education scored higher than those without previous nutrition education in total (54.0 ± 4.9% vs 46.8 ± 9.6%; p = 0.002) and sport (51.9 ± 12.5% vs 43.4 ± 11.8%; p = 0.005) nutrition knowledge. Findings suggest an importance of nutrition education at all levels of athletic competition to improve nutrition knowledge, which may empower athletes to make appropriate dietary decisions to support training and competition demands.
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Atletas , Desempenho Atlético , Dieta , Feminino , Educação em Saúde , Humanos , Masculino , Inquéritos e QuestionáriosRESUMO
Diet, exercise and the gut microbiome are all factors recognised to be significant contributors to cardiometabolic health. However, diet and exercise interventions to modify the gut microbiota to improve health are limited by poor understanding of the interactions between them. In this pilot study, we explored diet-exercise-microbiome dynamics in bodybuilders as they represent a distinctive group that typically employ well-defined dietary strategies and exercise regimes to alter their body composition. We performed longitudinal characterisation of diet, exercise, the faecal microbial community composition and serum metabolites in five bodybuilders during competition preparation and post-competition. All participants reduced fat mass while conserving lean mass during competition preparation, corresponding with dietary energy intake and exercise load, respectively. There was individual variability in food choices that aligned to individualised gut microbial community compositions throughout the study. However, there was a common shift from a high protein, low carbohydrate diet during pre-competition to a more macronutrient-balanced diet post-competition, which was associated with similar changes in the gut microbial diversity across participants. The circulating metabolite profiles also reflected individuality, but a subset of metabolites relating to lipid metabolism distinguished between pre- and post-competition. Changes in the gut microbiome and circulating metabolome were distinct for each individual, but showed common patterns. We conclude that further longitudinal studies will have greater potential than cross-sectional studies in informing personalisation of diet and exercise regimes to enhance exercise outcomes and improve health.
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Inter-individual differences in maturation-associated development can lead to variations in physical performance, resulting in performance (dis)advantages and maturation selection bias within youth sport systems. To address such bias and account for maturational differences, Maturation-based Corrective Adjustment Procedures (Mat-CAPs) could be beneficial. The present study aimed to: (1) determine maturity timing distributions in youth female swimming; (2) quantify the relationship between maturation status and 100-m front-crawl (FC) performance; (3) implement Mat-CAPs to remove maturational influences upon swimming performance. For Aim 1 and 2, participants were 663 female (10-15 years) swimmers who participated in 100-m FC events at Australian regional, state, and national-level competitions between 2016-2020 and underwent anthropometric assessment (mass, height and sitting height) to estimate maturity timing and offset. For Aim 3, participants aged 10-13 years were categorised into maturity timing categories. Maturity timing distributions for Raw ('All', 'Top 50%' and 'Top 25%') and Correctively Adjusted swim times were examined. Chi-square, Cramer's V and Odds Ratios determined the presence of maturation biases, while Mat-CAPs identified whether such biases were removed in targeted age and selection-groups. Results identified that between 10-13 years, a significantly higher frequency of 'early' maturers was apparent, although tapered toward higher frequencies of 'Late-normative' maturers by 14-15 years. A curvilinear relationship between maturity-offset and swim performance was identified (R2 = 0.51, p<0.001) and utilised for Mat-CAPs. Following Mat-CAPs application, maturity timing biases evident in affected age-groups (10-13 years), and which were magnified at higher selection levels ('Top 50%' & '25%' of swim performances) were predominantly removed. Findings highlight how maturation advantages in females occurred until approximately 13 years old, warranting restricted Mat-CAPs application. Mat-CAPS has the potential to improve female swimmer participation experiences and evaluation.
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Desempenho Atlético , Esportes Juvenis , Adolescente , Fatores Etários , Austrália , Feminino , Humanos , NataçãoRESUMO
Severe-intensity constant work rate (CWR) cycling tests simulate the high-intensity competition environment and are useful for monitoring training progression and adaptation, yet impose significant physiological and psychological strain, require substantial recovery, and may disrupt athlete training or competition preparation. A brief, minimally fatiguing test providing comparable information is desirable. Purpose To determine whether physiological variables measured during, and functional decline in maximal power output immediately after, a 2-min CWR test can act as a proxy for 4-min test outcomes. Methods Physiological stress ([Formula: see text] kinetics, heart rate, blood lactate concentrations ([La-]b)) was monitored and performance fatigability was estimated (as pre-to-post-CWR changes in 10-s sprint power) during 2- and 4-min CWR tests in 16 high-level cyclists ([Formula: see text] mlâkg-1âmin-1). The relationship between the 2- and 4-min CWR tests and the physiological variables that best relate to the performance fatigability were investigated. Results The 2-min CWR test evoked a smaller decline in sprint mechanical power (32% vs. 47%, p<0.001). Both the physiological variables (r = 0.66-0.96) and sprint mechanical power (r = 0.67-0.92) were independently and strongly correlated between 2- and 4-min tests. Differences in [Formula: see text] and [La-]b in both CWR tests were strongly associated with the decline in sprint mechanical power. Conclusion Strong correlations between 2- and 4-min severe-intensity CWR test outcomes indicated that the shorter test can be used as a proxy for the longer test. A shorter test may be more practical within the elite performance environment due to lower physiological stress and performance fatigability and should have less impact on subsequent training and competition preparation.
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Ciclismo , Ácido Láctico , Adaptação Fisiológica , Ciclismo/fisiologia , Fadiga , Frequência Cardíaca , Humanos , Consumo de Oxigênio/fisiologiaRESUMO
OBJECTIVES: The purpose of this study was to document the longitudinal strength and power characteristic changes and race performance changes of a skeleton athlete. METHOD: Longitudinal strength and power changes were assessed with strength and power diagnostic testing over a 9-year period. Trends over 9 years for relative strength were analyzed using a linear model. Push-start time was recorded across multiple tracks. Trends over 9 years for start performance at each track were assessed using a mixed-effects linear model to account for the impact of different tracks. Lower-body strength and power changes were assessed via a 1-repetition-maximum squat and a body-weight countermovement jump. The relationship between strength and power changes was assessed over time. The relationship between strength changes and start performance was determined by assessing the fixed effect of relative strength changes on push-start time. RESULTS: Relative lower-body strength ranged from 1.6 kg per body weight to 1.9 kg per body weight and showed a significant mean improvement of 0.05 kg per body weight per year (R2 = .71, P < .01). A negative correlation (R2 = .79) between relative strength changes and push-start performance across multiple tracks was found. The mixed-effects model indicated that push-start time improved significantly year to year (0.02 s; P < .001; R2 = .74) when controlling for the effect of track. CONCLUSIONS: The longitudinal analysis of push-start time and the associations with changes in strength suggest that training this quality can have a positive effect on push-start performance.
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Desempenho Atlético , Sistema Musculoesquelético , Treinamento Resistido , Atletas , Humanos , Força Muscular , Postura , EsqueletoRESUMO
OBJECTIVES: The aims of this cross-sectional study were to describe the client experiences of registered exercise professionals (REP) in regard to nutrition advice, and to identify factors considered important when selecting a REP. DESIGN: A convenience sample of fitness facility-users were recruited. Participants completed a 46 item online questionnaire. METHOD: Frequency distributions were calculated for nutrition advice received from a REP, confidence in the nutrition advice received, and factors considered when selecting a REP. The effect of sex and level of education on participant responses were investigated. RESULTS: A total of 455 individuals participated, of which 55.6% had worked with a REP. Participants working with a REP had received nutrition advice on body fat loss (77.4%), muscle gain (78.7%), and clinical nutrition (51.9%). Sex and level of education did not influence confidence in nutrition advice, with 60.7% of participants reporting being 'very or extremely confident' in the nutrition advice. Over half of participants (58.3%) prefer to work with a REP who offers nutrition advice. Basic and personal professional conduct were identified as 'very or extremely important' by >70% of participants when selecting a REP. CONCLUSION: Clients of REP prefer to work with a REP who provides nutrition advice and are generally confident in this advice. Educating fitness facility-users on the nutrition scope of practice of REP and promoting the role of accredited nutrition professionals should be advocated. Encouraging REP to work collaboratively with nutrition professionals will help ensure clients receive appropriate nutrition care, while better allowing REP to remain within their scope of practice.
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Exercício Físico , Política Nutricional , Terapia Nutricional/métodos , Educação de Pacientes como Assunto/métodos , Relações Profissional-Paciente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , ConfiançaRESUMO
OBJECTIVES: The global COVID-19 pandemic produced large-scale health and economic complications. Older people and those with comorbidities are particularly vulnerable to this virus, with nursing homes and long term care facilities (LTCF) experiencing significant morbidity and mortality associated with COVID-19 outbreaks. The aim of this rapid systematic review was to investigate measures implemented in LTCF to reduce transmission of COVID-19 and their effect on morbidity and mortality of residents, staff and visitors. SETTING: Long-term care facilities. PARTICIPANTS: Residents, staff and visitors of facilities. PRIMARY AND SECONDARY OUTCOME MEASURES: Databases (PubMed, EMBASE, CINAHL, Cochrane Databases and repositories and MedRXiv prepublished database) were systematically searched from inception to 27 July 2020 to identify studies reporting assessment of interventions to reduce transmission of COVID-19 in nursing homes among residents, staff or visitors. Outcome measures include facility characteristics, morbidity data, case fatalities and transmission rates. Due to study quality and heterogeneity, no meta-analysis was conducted. RESULTS: The search yielded 1414 articles, with 38 studies included. Reported interventions include mass testing, use of personal protective equipment, symptom screening, visitor restrictions, hand hygiene and droplet/contact precautions, and resident cohorting. Prevalence rates ranged from 1.2% to 85.4% in residents and 0.6% to 62.6% in staff. Mortality rates ranged from 5.3% to 55.3% in residents. CONCLUSIONS: Novel evidence in this review details the impact of facility size, availability of staff and practices of operating between multiple facilities, and for-profit status of facilities as factors contributing to the size and number of COVID-19 outbreaks. No causative relationships can be determined; however, this review provides evidence of interventions that reduce transmission of COVID-19 in LTCF. PROSPERO REGISTRATION NUMBER: CRD42020191569.
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COVID-19 , Idoso , Humanos , Assistência de Longa Duração , Casas de Saúde , Pandemias , SARS-CoV-2RESUMO
This study aimed to 1) identify what starting block outcome kinetics have the greatest relationship to 15 m start time; 2) investigate key mechanistic determinants of the block phase and how these forces are sequenced. One hundred and fifty-two high-level competitive swimmers were included in the study. Linear mixed modelling identified four on-block outcome kinetic variables (work, average power, horizontal take-off velocity (HTOV), and average acceleration) as having a very large relationship (R2 = 0.79-0.83) to 15 m start time, with average power having the most substantial impact. On-block force sequencing started with the rear leg, followed by upper limb grab forces and the front leg. Further exploration of underlying determinants was performed for average power and HTOV of the centre of mass. Multiple linear regression identified grab resultant peak force, rear resultant average force, front horizontal peak force, and resultant peak force as significant predictors of average power (R2 = 0.88). HTOV was predicted using the same variables, apart from the inclusion of rear horizontal peak force instead of rear resultant average force (R2 = 0.73). These findings may influence how strength and conditioning and skill acquisition interventions are designed to improve swim start performance.
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BACKGROUND: A paucity of research exists concerning physiological factors influencing heart structure and function in strength athletes. This pilot study investigated whether body composition and muscle performance are associated with indices of cardiac structure and function in experienced resistance trainers. METHODS: A cross-sectional study designed was employed to address the study aim. Seventeen males (median age 33.0 years) and eight females (median age 32.5 years) with backgrounds in bodybuilding and powerlifting participated in this study. Muscle performance, body composition and echocardiographic measures were performed. Mann-Whitney U-tests were used to examine differences between males and females. Spearman's Rho partial correlation analyses (adjusting for sex) were conducted to examine relationships between physical and echocardiogram parameters. RESULTS: Moderate to strong positive correlations were found between fat-free mass and aortic root, right ventricular internal dimension, interventricular septum thickness, left ventricular posterior wall thickness, left atrium area, left ventricular end-diastolic volume, and left ventricular end-systolic volume (r: 0.43-0.76, P≤0.03). Moderate to strong positive correlations were found between leg press 1RM and aortic root, left ventricular internal dimension diastole, left atrium area, left ventricular end-diastolic volume, and left ventricular end-systolic volume (r: 0.49-0.67, P≤0.02). CONCLUSIONS: Resistance trainers with greater fat-free mass and lower body strength appear to have larger cardiac structures. Changes in heart size and function are likely to result from long-term strenuous resistance training. Due to the suspected prevalence of performance enhancing drug use among powerlifters and bodybuilders, care is required to rule out pathological conditions.
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Ecocardiografia , Ventrículos do Coração , Adulto , Estudos Transversais , Diástole , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Projetos Piloto , Função Ventricular EsquerdaRESUMO
PURPOSE: First, to examine whether heart rate variability (HRV) responses can be modeled effectively via the Banister impulse-response model when the session rating of perceived exertion (sRPE) alone, and in combination with subjective well-being measures, are utilized. Second, to describe seasonal HRV responses and their associations with changes in critical speed (CS) in competitive swimmers. METHODS: A total of 10 highly trained swimmers collected daily 1-minute HRV recordings, sRPE training load, and subjective well-being scores via a novel smartphone application for 15 weeks. The impulse-response model was used to describe chronic root mean square of the successive differences (rMSSD) responses to training, with sRPE and subjective well-being measures used as systems inputs. Changes in CS were obtained from a 3-minute all-out test completed in weeks 1 and 14. RESULTS: The level of agreement between predicted and actual HRV data was R2 = .66 (.25) when sRPE alone was used. Model fits improved in the range of 4% to 21% when different subjective well-being measures were combined with sRPE, representing trivial-to-moderate improvements. There were no significant differences in weekly group averages of log-transformed (Ln) rMSSD (P = .34) or HRV coefficient of variation of Ln rMSSD (P = .12); however, small-to-large changes (d = 0.21-1.46) were observed in these parameters throughout the season. Large correlations were observed between seasonal changes in HRV measures and CS (changes in averages of Ln rMSSD: r = .51, P = .13; changes in coefficient of variation of Ln rMSSD: r = -.68, P = .03). CONCLUSION: The impulse-response model and data collected via a novel smartphone application can be used to model HRV responses to swimming training and nontraining-related stressors. Large relationships between seasonal changes in measured HRV parameters and CS provide further evidence for incorporating a HRV-guided training approach.