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1.
J Int Soc Sports Nutr ; 16(1): 50, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699159

RESUMO

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


Assuntos
Carboidratos da Dieta/administração & dosagem , Ingestão de Energia , Necessidades Nutricionais , Corrida/fisiologia , Fenômenos Fisiológicos da Nutrição Esportiva , Atletas , Desempenho Atlético , Comportamento Competitivo , Proteínas na Dieta/administração & dosagem , Humanos , Resistência Física , Corrida/classificação , Sociedades
2.
J Sports Sci ; 37(18): 2075-2085, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31124393

RESUMO

Athlete adherence to nutritional guidance is critical for optimal health and performance, yet little is known about the barriers and enablers to athletes' dietary behaviours within high-performance sport. To advance understanding, we applied a theoretical lens derived from the Capability, Opportunity, Motivation - Behaviour (COM-B) model and the Theoretical Domains Framework (TDF) to explore the qualitative accounts of sports nutritionists. Five focus groups comprising sports nutritionists working in Olympic and Paralympic sport (n = 14), professional sport (n = 6), or both (n = 6) were undertaken. Thematic analysis was conducted and the interpretations of the findings were guided by COM-B and the TDF. To achieve nutritional adherence, the behavioural analysis identified the need to intervene across all three COM-B components and at least five associated TDF domains (e.g., decision-making processes, reinforcement, social influences, behavioural regulation and environmental context and resource). For the first time, the findings illustrate the complex interplay of the training setting with the capabilities, opportunities, and motivation of the practitioners, athletes and coaches. By applying established behavioural science theories to sports nutrition, the foundations for the development of targeted and multifaceted behavioural interventions addressing athlete dietary adherence in high-performance sport have been laid.


Assuntos
Atletas/psicologia , Dieta , Motivação , Fenômenos Fisiológicos da Nutrição Esportiva , Adulto , Ciências do Comportamento , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Nutricionistas , Cooperação do Paciente
3.
Int J Sport Nutr Exerc Metab ; 29(5): 512-517, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31142173

RESUMO

The practice of rapid weight loss (RWL) in mixed martial arts (MMA) is an increasing concern but data remain scarce. The aim of this study was to investigate the prevalence, magnitude, methods, and influencers of RWL in professional and amateur MMA athletes. MMA athletes (N = 314; 287 men and 27 women) across nine weight categories (strawweight to heavyweight), completed a validated questionnaire adapted for this sport. Sex-specific data were analyzed, and subgroup comparisons were made between athletes competing at professional and amateur levels. Most athletes purposefully reduced body weight for competition (men: 97.2%; women: 100%). The magnitude of RWL in 1 week prior to weigh-in was significantly greater for professional athletes compared with those competing at amateur level (men: 5.9% vs. 4.2%; women: 5.0% vs. 2.1% of body weight; p < .05). In the 24 hr preceding weigh-in, the magnitude of RWL was greater at professional than amateur level in men (3.7% vs. 2.5% of body weight; p < .05). Most athletes "always" or "sometimes" used water loading (72.9%), restricting fluid intake (71.3%), and sweat suits (55.4%) for RWL. Coaches were cited as the primary source of influence on RWL practices (men: 29.3%; women: 48.1%). There is a high reported prevalence of RWL in MMA, at professional and amateur levels. Our findings, constituting the largest inquiry to date, call for urgent action from MMA organizations to safeguard the health and well-being of athletes competing in this sport.


Assuntos
Peso Corporal , Artes Marciais , Perda de Peso , Adulto , Atletas , Feminino , Humanos , Masculino , Prevalência , Adulto Jovem
4.
Psychooncology ; 28(3): 505-510, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30552786

RESUMO

OBJECTIVE: Sun safety is crucial for preventing skin cancer. This study evaluated a school-based intervention based on the theory of planned behaviour (TPB), which aimed to encourage sun-protective behaviour among adolescents. METHODS: Secondary school students (N = 382; 61.1% female; Mage  = 13.73 y) in Queensland, Australia, participated in the study. Schools were randomly allocated to an intervention or control group. The intervention focussed on fostering positive attitudes, increasing perceptions of normative support, and strengthening control perceptions. Participants completed questionnaires assessing the TPB variables and sun-protective behaviour (weekday and weekend) 1 week before intervention (time 1), 1 week after intervention (time 2), and 4 weeks after intervention (time 3). RESULTS: With baseline between-group differences in TPB variables matched, repeated-measures multivariate analysis of variance was used to evaluate the Time × Condition effects across time. Multigroup comparisons using path models traced the intervariable changes. From times 1 to 3, a significant improvement in weekend sun-protective behaviour was identified in the intervention group (but not the control group), whereas cognitions showed no significant changes across time for either conditions. Multigroup comparisons on path coefficients between the intervention and control group participants indicated that the intervention group members formed stronger positive associations between perceived behavioural control and intention at time 2 and between perceived control and behaviour at time 3. CONCLUSION: The significant behavioural change on weekends highlights the value of targeting control perceptions, which may encourage adolescents' sun-protective behaviour. Further studies are needed to understand the absence of significant changes in weekday sun-safe behaviour among this at-risk cohort.


Assuntos
Comportamentos Relacionados com a Saúde , Educação em Saúde/métodos , Serviços de Saúde Escolar/organização & administração , Neoplasias Cutâneas/prevenção & controle , Queimadura Solar/prevenção & controle , Adolescente , Análise de Variância , Austrália , Feminino , Humanos , Masculino , Teoria Psicológica , Queensland , Neoplasias Cutâneas/psicologia , Luz Solar/efeitos adversos , Inquéritos e Questionários
5.
Health Promot J Austr ; 30(2): 263-266, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30076670

RESUMO

ISSUE ADDRESSED: The prevalence of skin cancer remains at a high level in Australia. Young female Australian beachgoers are an at-risk population of skin cancer. Research on sun-protective beliefs held by this at-risk group is limited. METHODS: Based on the Theory of Planned Behaviour (TPB), we conducted a formative study to understand key sun safe messages among young female beachgoers in Queensland, including an elicitation study (Phase 1; N = 21, Mage  = 24.30 years) and a two-wave questionnaire survey (Phase 2; N = 140, Mage  = 23.96 years). RESULTS: Following content analysis and regression analyses, three key beliefs were identified: "be uncomfortable and/or unstylish" (behavioural belief), "friends and peers" (normative belief) and "lack of motivation to reapply sunscreen" (control belief). CONCLUSIONS: The results highlight the influences of friends and peers on beachgoers' sun-protective behaviour for this young female adult cohort. Compared to previous findings among the general population, discrepancies in beliefs suggest interventions targeting this cohort should specifically focus on fashionable sun safe images and motivation to reapply sunscreen. SO WHAT?: Future health promotion and public education should utilise various strategies according to specific groups given the discrepancies identified in beliefs. For female beachgoers, sun safe images and motivations should be the primary foci.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Motivação , Neoplasias Cutâneas/prevenção & controle , Queimadura Solar/prevenção & controle , Queimadura Solar/psicologia , Protetores Solares/uso terapêutico , Adulto , Austrália , Feminino , Amigos/psicologia , Humanos , Grupo Associado , Estudos Prospectivos , Queensland , Neoplasias Cutâneas/psicologia , Inquéritos e Questionários , Adulto Jovem
6.
Int J Sport Nutr Exerc Metab ; 28(5): 553-557, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29345174

RESUMO

Designing and implementing successful dietary intervention is integral to the role of sport nutrition professionals as they attempt to positively change the dietary behavior of athletes. High-performance sport is a time-pressured environment where immediate results can often supersede pursuit of the most effective evidence-based practice. However, efficacious dietary intervention necessitates comprehensive, systematic, and theoretical behavioral design and implementation, if the habitual dietary behaviors of athletes are to be positively changed. Therefore, this case study demonstrates how the Behaviour Change Wheel was used to design and implement an effective nutritional intervention within a professional rugby league. The eight-step intervention targeted athlete consumption of a high-quality dietary intake of 25.1 MJ each day to achieve an overall body mass increase of 5 kg across a 12-week intervention period. The capability, opportunity, motivation, and behavior model and affordability, practicability, effectiveness/cost-effectiveness, acceptability, safety, and equity criteria were used to identify population-specific intervention functions, policy categories, behavior change techniques, and modes of intervention delivery. The resulting intervention was successful, increasing the average daily energy intake of the athlete to 24.5 MJ, which corresponded in a 6.2 kg body mass gain. Despite consuming 0.6 MJ less per day than targeted, secondary outcome measures of diet quality, strength, body composition, and immune function all substantially improved, supporting sufficient energy intake and the overall efficacy of a behavioral approach. Ultimately, the Behaviour Change Wheel provides sport nutrition professionals with an effective and practical stepwise method to design and implement effective nutritional interventions for use within high-performance sport.


Assuntos
Dieta , Futebol Americano , Necessidades Nutricionais , Fenômenos Fisiológicos da Nutrição Esportiva , Adolescente , Atletas , Composição Corporal , Dietética , Ingestão de Energia , Humanos , Masculino
7.
Psychol Health ; 31(11): 1272-92, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27334551

RESUMO

OBJECTIVE: To synthesise theory of planned behaviour (TPB) relationships, using meta-analysis, and test the predictive utility of the model for sun protection behaviour. DESIGN: Thirty-eight samples were identified via database/manual searches and academic society posts based on the criteria: measuring sun-protective intentions and/or prospective behaviour; using the TPB/theory of reasoned action as a basis of measurement; and providing bivariate correlations for at least one relevant TPB association. MAIN OUTCOME MEASURES: Sun-protective intentions and behaviours. RESULTS: The sample-weighted average effects were moderate-to-strong with attitudes showing the strongest association with intention (r+ = 0.494), followed by perceived behavioural control (PBC; r+ = 0.451), and subjective norm (r+ = 0.419). Intentions showed a stronger association with prospective behaviour (r+ = 0.486) compared to PBC (r+ = 0.314). A total of 39% of variance in intentions and 25% of variance in behaviour were explained. Publication bias was not evident. Moderator analyses showed that TPB associations were stronger when measures specified the Target, Action, Context and Time; in non-student samples; and when follow-up exceeded two weeks. CONCLUSION: Despite recent criticism, this review shows that the TPB explains a large amount of variance in sun protection and that TPB associations are robust across different populations.


Assuntos
Comportamentos Relacionados com a Saúde , Intenção , Teoria Psicológica , Luz Solar/efeitos adversos , Humanos , Estudos Prospectivos , Roupa de Proteção/estatística & dados numéricos , Neoplasias Cutâneas/prevenção & controle , Neoplasias Cutâneas/psicologia , Protetores Solares/administração & dosagem
8.
Int J Sport Nutr Exerc Metab ; 26(6): 506-515, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27096473

RESUMO

Good nutrition is essential for the physical development of adolescent athletes, however data on dietary intakes of adolescent rugby players are lacking. This study quantified and evaluated dietary intake in 87 elite male English academy rugby league (RL) and rugby union (RU) players by age (under 16 (U16) and under 19 (U19) years old) and code (RL and RU). Relationships of intakes with body mass and composition (sum of 8 skinfolds) were also investigated. Using 4-day diet and physical activity diaries, dietary intake was compared with adolescent sports nutrition recommendations and the UK national food guide. Dietary intake did not differ by code, whereas U19s consumed greater energy (3366 ± 658 vs. 2995 ± 774 kcal·day-1), protein (207 ± 49 vs. 150 ± 53 g·day-1) and fluid (4221 ± 1323 vs. 3137 ± 1015 ml·day-1) than U16s. U19s consumed a better quality diet than U16s (greater intakes of fruit and vegetables; 4.4 ± 1.9 vs. 2.8 ± 1.5 servings·day-1; nondairy proteins; 3.9 ± 1.1 vs. 2.9 ± 1.1 servings·day-1) and less fats and sugars (2.0 ± 1. vs. 3.6 ± 2.1 servings·day-1). Protein intake vs. body mass was moderate (r = .46, p < .001), and other relationships were weak. The findings of this study suggest adolescent rugby players consume adequate dietary intakes in relation to current guidelines for energy, macronutrient and fluid intake. Players should improve the quality of their diet by replacing intakes from the fats and sugars food group with healthier choices, while maintaining current energy, and macronutrient intakes.


Assuntos
Ingestão de Energia , Exercício Físico , Futebol Americano , Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente , Composição Corporal , Estatura , Índice de Massa Corporal , Peso Corporal , Estudos Transversais , Registros de Dieta , Carboidratos da Dieta/administração & dosagem , Gorduras na Dieta/administração & dosagem , Proteínas na Dieta/administração & dosagem , Frutas , Humanos , Masculino , Avaliação Nutricional , Recomendações Nutricionais , Fenômenos Fisiológicos da Nutrição Esportiva , Reino Unido , Verduras , Adulto Jovem
9.
Int J Sport Nutr Exerc Metab ; 22(3): 212-9, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22349112

RESUMO

The Vendée Globe is a solo round-the-world sailing race without stopovers or assistance, a physically demanding challenge for which appropriate nutrition should maintain energy balance and ensure optimum performance. This is an account of prerace nutritional preparation with a professional and experienced female racer and assessment of daily nutritional intake (NI) during the race using a multimethod approach. A daily energy intake (EI) of 15.1 MJ/day was recommended for the race and negotiated down by the racer to 12.7 MJ/day, with carbohydrate and fluid intake goals of 480 g/day and 3,020 ml/day, respectively. Throughout the 99-day voyage, daily NI was recorded using electronic food diaries and inventories piloted during training races. NI was assessed and a postrace interview and questionnaire were used to evaluate the intervention. Fat mass (FM) and fat-free mass (FFM) were assessed pre- (37 days) and postrace (11 days) using dual-energy X-ray absorptiometry, and body mass was measured before the racer stepped on the yacht and immediately postrace. Mean EI was 9.2 MJ/day (2.4-14.3 MJ/day), representing a negative energy balance of 3.5 MJ/day under the negotiated EI goal, evidenced by a 7.9-kg loss of body mass (FM -7.5 kg, FFM -0.4 kg) during the voyage, with consequent underconsumption of carbohydrate by ~130 g/day. According to the postrace yacht food inventory, self-reported EI was underreported by 7%. This intervention demonstrates the practicality of the NI approach and assessment, but the racer's nutrition strategy can be further improved to facilitate meeting more optimal NI goals for performance and health. It also shows that evaluation of NI is possible in this environment over prolonged periods, which can provide important information for optimizing nutritional strategies for ocean racing.


Assuntos
Dieta , Ingestão de Energia , Desnutrição , Avaliação Nutricional , Resistência Física , Esportes , Perda de Peso , Adulto , Registros de Dieta , Carboidratos da Dieta/administração & dosagem , Comportamento de Ingestão de Líquido , Comportamento Alimentar , Feminino , Humanos , Entrevistas como Assunto , Estado Nutricional , Autorrelato , Navios , Inquéritos e Questionários
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