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1.
Front Sports Act Living ; 4: 957950, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36060624

RESUMO

Purpose: Cherry juice (CJ) and cold water immersion (CWI) are both effective recovery strategies following strenuous endurance exercise. However, athletes routinely combine recovery interventions and less is known about the impact of a combined CJ and CWI protocol. Therefore, this study investigated the effects of combining CWI and CJ (a "cocktail" (CT)) on inflammation and muscle damage following a marathon. Methods: A total 39 endurance trained males were randomly assigned to a placebo (PL), CWI, CJ, or CT group before completing a trail marathon run. Muscle damage (creatine kinase (CK)), muscle function (maximal voluntary isometric contraction (MVIC)), and inflammation (interleukin-6 (IL-6); C-reactive protein (CRP)) were measured at baseline, immediately after marathon (only IL-6), 24 h, and 48 h after marathon. Results: There were no statistically significant differences between groups and no group × time interaction effects for any of the dependent variables. Confidence intervals (CI) illustrated that CT had unclear effects on inflammation (IL-6; CRP) and MVIC, but may have increased CK to a greater extent than PL and CJ conditions. Conclusion: There is no evidence of an additive effect of CJ and CWI when the treatments are used in conjunction with each other. On the contrary, combining CJ and CWI may result in slightly increased circulating CK.

2.
J Strength Cond Res ; 35(10): 2720-2727, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34324460

RESUMO

ABSTRACT: Wilson, LJ, Dimitriou, L, Hills, FA, Gondek, MB, van Wyk, A, Turek, V, Rivkin, T, Villiere, A, Jarvis, P, Miller, S, Turner, A, and Cockburn, E. Cold water immersion offers no functional or perceptual benefit compared to a sham intervention during a resistance training program. J Strength Cond Res 35(10): 2720-2727, 2021-Cold water immersion (CWI) is regularly used by athletes as a postexercise recovery strategy, but relatively little is understood about potential training adaptations associated with habitual use. The aim of this study was to investigate the influence of repeated CWI or a sham intervention on adaptations to a lower body resistance training program. Thirteen men (26 ± 6 years; 83.6 ± 15.7 kg) familiar with resistance training were allocated into a CWI (10 minutes at 10° C) or sham group and completed 2 × 4-week blocks of lower body resistance training. Subjects completed a total of 16 training sessions (2 × session·week-1), with each session immediately followed by their allocated recovery intervention. Measures of perceptual markers, muscle function, and muscle architecture were recorded at baseline, midpoint, and post-training. Data were analyzed using factorial analysis of variances. The training program resulted in significant increases in muscle fibre pennation angle (p = 0.009), isometric peak force (p = 0.018), and 1/4 squat (p < 0.001) with no differences between groups (all p > 0.05). There were no differences in perceptual responses between groups. Despite the popularity of CWI as a postexercise recovery intervention, the findings from the present study demonstrated no functional or perceptual benefit compared with a sham intervention during progressive strength and power training. Furthermore, there was no detrimental impact of CWI on morphological adaptations after 16 exposures. These findings are important for athletes and practitioners wishing to use CWI as an acute recovery strategy after training, without blunting potential training adaptations.


Assuntos
Treinamento Resistido , Adaptação Fisiológica , Temperatura Baixa , Humanos , Imersão , Masculino , Fibras Musculares Esqueléticas , Músculo Esquelético , Água
3.
Scand J Med Sci Sports ; 30(11): 2116-2129, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32681596

RESUMO

The effects of 4 mg·kg-1 caffeine ingestion on strength and power were investigated for the first time, in resistance-trained females during the early follicular phase utilizing a randomized, double-blind, placebo-controlled, crossover design. Fifteen females (29.8 ± 4.0 years, 63.8 ± 5.5 kg [mean ± SD]) ingested caffeine or placebo 60 minutes before completing a test battery separated by 72 hours. One-repetition maximum (1RM), repetitions to failure (RTF) at 60% of 1RM, was assessed in the squat and bench press. Maximal voluntary contraction torque (MVC) and rate of force development (RFD) were measured during isometric knee extensions, while utilizing interpolated twitch technique to measure voluntary muscle activation. Maximal power and jump height were assessed during countermovement jumps (CMJ). Caffeine metabolites were measured in plasma. Adverse effects were registered after each trial. Caffeine significantly improved squat (4.5 ± 1.9%, effect size [ES]: 0.25) and bench press 1RM (3.3 ± 1.4%, ES: 0.20), and squat (15.9 ± 17.9%, ES: 0.31) and bench press RTF (9.8 ± 13.6%, ES: 0.31), compared to placebo. MVC torque (4.6 ± 7.3%, ES: 0.26), CMJ height (7.6 ± 4.0%, ES: 0.50), and power (3.8 ± 2.2%, ES: 0.24) were also significantly increased with caffeine. There were no differences in RFD or muscle activation. Plasma [caffeine] was significantly increased throughout the protocol, and mild side effects of caffeine were experienced by only 3 participants. This study demonstrated that 4 mg·kg-1 caffeine ingestion enhanced maximal strength, power, and muscular endurance in resistance-trained and caffeine-habituated females during the early follicular phase, with few adverse effects. Female strength and power athletes may consider using this dose pre-competition and -training as an effective ergogenic aid.


Assuntos
Bebidas , Cafeína/administração & dosagem , Fase Folicular/fisiologia , Força Muscular/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/administração & dosagem , Treinamento Resistido , Adulto , Cafeína/efeitos adversos , Cafeína/sangue , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Contração Isométrica , Joelho/fisiologia , Mialgia/fisiopatologia , Percepção/fisiologia , Substâncias para Melhoria do Desempenho/efeitos adversos , Substâncias para Melhoria do Desempenho/sangue , Esforço Físico/fisiologia , Exercício Pliométrico , Treinamento Resistido/métodos , Levantamento de Peso/fisiologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-31671715

RESUMO

In spite of the extensive research on incidence site and type of injury in ballet and modern dancers, limited studies on injury in DanceSport have been reported. Therefore, this study determined retrospectively (within last 12 months) incidence, severity, site and type of injury, between gender and age-class in DanceSport. Participants were 97 international sport-dancers (female, 41; male, 56). Sixty-six (69%) dancers reported 96 injuries (1.00 (range = 4)) injuries per dancer) and an injury incidence of 1.7 (range = 14) per 1000 h. Females revealed significantly higher median injury incidence (females, 2.6 (range = 14); males, 1.9 (range = 9), p < 0.05) than males. A total of 61.5% of all injuries recorded were traumatic with a significant gender difference (Wald chi-square = 11.616, df = 1, p < 0.01). Injury severity was 3 (range 240) days with an interaction effect between gender and age-class (Wald chi-square = 251.374, df = 3, p < 0.001). Meanwhile, 72.3% of the dancers reported not including sport specific exercises besides dancing. These findings show gender and age-class differences in injury incidence, type and severity. Therefore, to reduce the likelihood of injuries, the implementation of supplemental DanceSport specific exercises that also considers the gender and age-class anatomical, functional, and choreographic demand differences in the training program should be recognized.


Assuntos
Traumatismos em Atletas/etiologia , Dança/lesões , Adolescente , Adulto , Fatores Etários , Traumatismos em Atletas/epidemiologia , Traumatismos em Atletas/prevenção & controle , Criança , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Eslovênia/epidemiologia , Adulto Jovem
6.
Eur J Appl Physiol ; 119(1): 135-147, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30310979

RESUMO

PURPOSE: The use of cryotherapy as a recovery intervention is prevalent amongst athletes. Performance of high volume, heavy load resistance exercise is known to result in disturbances of muscle function, perceptual responses and blood borne parameters. Therefore, this study investigated the influence of cold water immersion (CWI), whole body cryotherapy (WBC) or a placebo (PL) intervention on markers of recovery following an acute resistance training session. METHODS: 24 resistance trained males were matched into a CWI (10 min at 10 °C), WBC (3- and 4 min at - 85 °C) or PL group before completing a lower body resistance training session. Perceptions of soreness and training stress, markers of muscle function, inflammation and efflux of intracellular proteins were assessed before, and up to 72 h post exercise. RESULTS: The training session resulted in increased soreness, disturbances of muscle function, and increased inflammation and efflux of intracellular proteins. Although WBC attenuated soreness at 24 h, and positively influenced peak force at 48 h compared to CWI and PL, many of the remaining outcomes were trivial, unclear or favoured the PL condition. With the exception of CRP at 24 h, neither cryotherapy intervention attenuated the inflammatory response compared to PL. CONCLUSION: There was some evidence to suggest that WBC is more effective than CWI at attenuating select perceptual and functional responses following resistance training. However, neither cryotherapy intervention was more effective than the placebo treatment at accelerating recovery. The implications of these findings should be carefully considered by individuals employing cryotherapy as a recovery strategy following heavy load resistance training.


Assuntos
Crioterapia/métodos , Mialgia/terapia , Treinamento Resistido/efeitos adversos , Adulto , Estudos de Casos e Controles , Crioterapia/efeitos adversos , Humanos , Imersão , Masculino , Percepção , Água
7.
Eur J Appl Physiol ; 118(1): 153-163, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29127510

RESUMO

PURPOSE: Cryotherapy is an increasingly popular recovery strategy used in an attempt to attenuate the negative impact of strenuous physical activity on subsequent exercise. Therefore, this study aimed to assess the effects of whole body cryotherapy (WBC) and cold water immersion (CWI) on markers of recovery following a marathon. METHODS: Thirty-one endurance trained males completed a marathon. Participants were randomly assigned to a CWI, WBC or placebo group. Perceptions of muscle soreness, training stress and markers of muscle function were recorded before the marathon and at 24 and 48 h post exercise. Blood samples were taken at baseline, post intervention and 24 and 48 h post intervention to assess inflammation and muscle damage. RESULTS: WBC had a harmful effect on muscle function compared to CWI post marathon. WBC positively influenced perceptions of training stress compared to CWI. With the exception of C-reactive protein (CRP) at 24 and 48 h, neither cryotherapy intervention positively influenced blood borne markers of inflammation or structural damage compared to placebo. CONCLUSION: The findings show WBC has a negative impact on muscle function, perceptions of soreness and a number of blood parameters compared to CWI, contradicting the suggestion that WBC may be a superior recovery strategy. Further, cryotherapy is no more effective than a placebo intervention at improving functional recovery or perceptions of training stress following a marathon. These findings lend further evidence to suggest that treatment belief and the placebo effect may be largely responsible for the beneficial effects of cryotherapy on recovery following a marathon.


Assuntos
Hipotermia Induzida/métodos , Fadiga Muscular , Mialgia/terapia , Condicionamento Físico Humano/efeitos adversos , Adulto , Banhos , Humanos , Hipotermia Induzida/efeitos adversos , Masculino , Pessoa de Meia-Idade , Mialgia/etiologia , Mialgia/reabilitação , Recuperação de Função Fisiológica , Corrida
8.
J Strength Cond Res ; 31(11): 3128-3136, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28902120

RESUMO

Turner, AN, Kilduff, LP, Marshall, GJG, Phillips, J, Noto, A, Buttigieg, C, Gondek, M, Hills, FA, and Dimitriou, L. Competition intensity and fatigue in elite fencing. J Strength Cond Res 31(11): 3128-3136, 2017-As yet, no studies have characterized fencing competitions. Therefore, in elite male foilists and across 2 competitions, we investigated their countermovement jump height, testosterone (T), cortisol (C), alpha-amylase (AA), immunoglobulin A (IgA), heart rate (HR), blood lactate (BL), and rating of perceived exertion (RPE). Average (±SD) scores for RPE, BL, and HR (average, max, and percentage of time ≥80% HRmax) were highest in the knockout bouts compared with poules (8.5 ± 1.3 vs. 5.7 ± 1.3, 3.6 ± 1.0 vs. 3.1 ± 1.4 mmol·L, 171 ± 5 vs. 168 ± 8 b·min, 195 ± 7 vs. 192 ± 7 b·min, 74 vs. 68%); however, only significant (p ≤ 0.05) for RPE. Countermovement jump height, albeit nonsignificantly (p > 0.05), increased throughout competition and dropped thereafter. Although responses of C, AA, and IgA showed a tendency to increase during competition and drop thereafter (T and T:C doing the opposite), no significant differences were noted for any analyte. Results suggest that fencing is a high-intensity anaerobic sport, relying on alactic energy sources. However, some bouts evoke BL values of ≥4 mmol·L and thus derive energy from anaerobic glycolysis. High HRs appear possible on account of ample within- and between-bout rest. The small competition load associated with fencing competitions may explain the nonsignificant findings noticed.


Assuntos
Atletas , Esforço Físico/fisiologia , Esportes/fisiologia , Adulto , Teste de Esforço , Glicólise , Frequência Cardíaca/fisiologia , Humanos , Hidrocortisona/biossíntese , Ácido Láctico/biossíntese , Masculino , Descanso , Medicina Esportiva , Testosterona/biossíntese , Adulto Jovem , alfa-Amilases/biossíntese
9.
J R Army Med Corps ; 163(1): 39-47, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26929111

RESUMO

BACKGROUND: Respiratory illnesses are a leading cause of morbidity and medical discharge in the military. This study aimed to investigate the effects of baseline aerobic fitness on haematological, salivary and mood variables, and simultaneously, in a novel approach, to identify factors precipitating illness and attrition rate in recruits during military training. METHODS: Thirty-five healthy male recruits from an Army Training Regiment undertaking 12 weeks of training were prospectively investigated. Their 2.4 km run time (RT) was used as a surrogate of baseline aerobic fitness. Saliva and venous blood samples were analysed for secretory IgA, full blood counts and cell cytokine production (interleukin (IL) 6 and IL-8), respectively. Each recruit completed questionnaires on mood profile, and gastrointestinal and upper respiratory tract symptoms (URTS). RESULTS: Significant salivary and haematological perturbations were observed and coincided with increased duration of URTS/week and mood disturbance over this military training period. From Start to End: leucocyte count decreased by 28% (p<0.001); neutrophil percentage (%) decreased by 13% (p<0.01); lymphocyte % increased by 17% (p<0.05); the neutrophil:lymphocyte ratio decreased by 22% (p<0.01); eosinophil% increased by 71% (p<0.01). From Start to Mid to End: monocyte% increased by 68% at Mid (p<0.01) but only by 30% at End (p<0.01); IL-6 increased by 39% at Mid (p<0.01) and a further 61% by End. The 2.4 km RT was significantly associated with URTS duration (p<0.01). In addition, a 1-min increase in 2.4 km RT increased a recruit's risk 9.8-fold of developing URTS lasting, on average, 3.36 days/week. In recruits ranked with high-URTS duration their RT was 48 s slower (p<0.01) than those with low-URTS, and their attrition rate reached 45%. CONCLUSIONS: The least fit recruits may have found training more physically demanding as reflected in the higher URTS duration, which may have led to a high attrition rate from the Army. It is worth considering that baseline aerobic fitness might be an important factor in illness development and attrition rate in recruits during this type of military training.


Assuntos
Doenças Hematológicas/epidemiologia , Militares , Transtornos do Humor/epidemiologia , Seleção de Pessoal , Aptidão Física , Doenças das Glândulas Salivares/epidemiologia , Adulto , Doenças Hematológicas/metabolismo , Humanos , Imunoglobulina A/metabolismo , Incidência , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Masculino , Transtornos do Humor/metabolismo , Estudos Prospectivos , Doenças das Glândulas Salivares/metabolismo , Adulto Jovem
10.
J Strength Cond Res ; 30(11): 3134-3139, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26950343

RESUMO

Turner, AN, Marshall, G, Phillips, J, Noto, A, Buttigieg, C, Chavda, S, Downing, W, Atlay, N, Dimitriou, L, and Kilduff, L. Physical characteristics underpinning repetitive lunging in fencing. J Strength Cond Res 30(11): 3134-3139, 2016-Given the repetitive demand to execute lunging and changes in direction within fencing, the ability to sustain these at maximal capacity is fundamental to performance. The aim of this study was threefold. First, to provide normative values for this variable referred to as repeat lunge ability (RLA) and second to identify the physical characteristics that underpin it. Third, was to establish if a cause and effect relationship existed by training the associated characteristics. Assessment of lower-body power, reactive strength, speed, change of direction speed (CODS), and a sport-specific RLA were conducted on senior and junior elite male fencers (n = 36). Fencers were on average (±SD) 18.9 ± 3.2 years of age, 174.35 ± 10.42 cm tall, 70.67 ± 7.35 kg in mass, and 8.5 ± 4.2 years fencing experience. The RLA test had average work times of 16.03 ± 1.40 seconds and demonstrated "large" to "very large" associations with all tested variables, but in particular CODS (r = 0.70) and standing broad jump (SBJ; r = -0.68). Through linear regression analysis, these also provided a 2-predictor model accounting for 61% of the common variance associated with RLA. A cause and effect relationship with SBJ and CODS was confirmed by the training group, where RLA performance in these fencers improved from 15.80 ± 1.07 to 14.90 ± 0.86 seconds, with the magnitude of change reported as "moderate" (effect size (ES) = 0.93). Concurrent improvements were also noted in both SBJ (216.86 ± 17.15 vs. 221.71 ± 17.59 cm) and CODS (4.44 ± 0.29 vs. 4.31 ± 0.09 seconds) and while differences were only significant in SBJ, magnitudes of change were classed as "small" (ES = 0.28) and "moderate" (ES = 0.61), respectively. In conclusion, to improve RLA strength and conditioning coaches should focus on improving lower-body power and reactive strength, noting that jump training and plyometrics designed to enhance horizontal propulsion may be most effective, and translate to improvement in CODS also.


Assuntos
Desempenho Atlético/fisiologia , Extremidade Inferior/fisiologia , Força Muscular/fisiologia , Resistência Física/fisiologia , Adolescente , Humanos , Masculino , Condicionamento Físico Humano
11.
J Int Soc Sports Nutr ; 12: 22, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25983669

RESUMO

BACKGROUND: Prolonged exercise, such as marathon running, has been associated with an increase in respiratory mucosal inflammation. The aim of this pilot study was to examine the effects of Montmorency cherry juice on markers of stress, immunity and inflammation following a Marathon. METHODS: Twenty recreational Marathon runners consumed either cherry juice (CJ) or placebo (PL) before and after a Marathon race. Markers of mucosal immunity secretory immunoglobulin A (sIgA), immunoglobulin G (IgG), salivary cortisol, inflammation (CRP) and self-reported incidence and severity of upper respiratory tract symptoms (URTS) were measured before and following the race. RESULTS: All variables except secretory IgA and IgG concentrations in saliva showed a significant time effect (P <0.01). Serum CRP showed a significant interaction and treatment effect (P < 0.01). The CRP increase at 24 and 48 h post-Marathon was lower (P < 0.01) in the CJ group compared to PL group. Mucosal immunity and salivary cortisol showed no interaction effect or treatment effect. The incidence and severity of URTS was significantly greater than baseline at 24 h and 48 h following the race in the PL group and was also greater than the CJ group (P < 0.05). No URTS were reported in the CJ group whereas 50 % of runners in the PL group reported URTS at 24 h and 48 h post-Marathon. CONCLUSIONS: This is the first study that provides encouraging evidence of the potential role of Montmorency cherries in reducing the development of URTS post-Marathon possibly caused by exercise-induced hyperventilation trauma, and/or other infectious and non-infectious factors.


Assuntos
Sucos de Frutas e Vegetais , Prunus avium , Doenças Respiratórias/dietoterapia , Doenças Respiratórias/epidemiologia , Corrida , Estresse Fisiológico , Adulto , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Feminino , Humanos , Hidrocortisona/metabolismo , Imunoglobulina A/metabolismo , Imunoglobulina G/metabolismo , Incidência , Inflamação/dietoterapia , Masculino , Pessoa de Meia-Idade , Resistência Física , Projetos Piloto , Adulto Jovem
12.
J Strength Cond Res ; 28(10): 3001-11, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24714533

RESUMO

Fencing is one of only a few sports that have featured at every modern Olympic games. Despite this, there is still much the sport science team does not know regarding competition demands and athlete physical characteristics. This review aims to undertake an analysis of the current literature to identify what is known, and questions that must be answered to optimize athlete support in this context. In summary, fencing is an explosive sport requiring energy production predominately from anaerobic sources. Lunging and change-of-direction speed seem vital to performance, and strength and power qualities underpin this. In the elimination rounds, fencers are likely to accumulate high levels of blood lactate, and so high-intensity interval training is recommended to reduce the intolerance to and the accumulation of hydrogen ions. Injury data report the hamstrings as a muscle group that should be strengthened and address imbalances caused by continuous fencing in an asymmetrical stance.


Assuntos
Desempenho Atlético/fisiologia , Movimento/fisiologia , Traumatismos em Atletas/etiologia , Fenômenos Biomecânicos , Humanos , Condicionamento Físico Humano , Treinamento Resistido , Fatores de Risco , Estudos de Tempo e Movimento
13.
BMJ Open ; 4(2): e004369, 2014 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-24523427

RESUMO

OBJECTIVE: To determine bone mineral density (BMD) and the associations among BMD, menstrual history, disordered eating (DE), training history, intentional weight loss (IWL) and rib pain for the first time in female lightweight rowers. SETTING: 9 lightweight rowing clubs, UK. PARTICIPANTS: 29 Caucasian female lightweight rowers volunteered. 21 (12 active, 9 retired) completed the study. INCLUSION CRITERIA: female lightweight rowers aged over 18 years. EXCLUSION CRITERIA: participants with a history of bone disease, used medications known to influence BMD or if they were pregnant, lactating or postmenopausal. MAIN OUTCOME MEASURES: Dual-energy X-ray absorptiometry measured total body (TB) composition and BMD at the spine, femoral neck (FN), radius and TB. DE, oligomenorrhoea/amenorrhoea years; rib pain and training history. RESULTS: DE was reported in six of the rowers. The active with DE started rowing younger (p<0.05) than those without, and their amount of IWL was associated with Eating Attitudes Test-26 score (p<0.05). Some participants reported a history of oligomenorrhoea/amenorrhoea 17 (76%) and/or rib pain 7 (32%) with those with rib pain having lower spine and TB Z-scores (p<0.05) than those without. Those with oligomenorrhoea/amenorrhoea had lower spine Z-scores (p<0.01) than those without. Twelve participants had low BMD; three at spine; one at FN; and eight at radius. Thirteen per cent of mean total training hours (18.6±9.1 h/week) were spent strength training (2.4±2.2 h/week). CONCLUSIONS: Upper body exercises incorporating multidimensional high peak bone strain were not reported and may need to be considered in their strength training to improve radial BMD. Results suggest IWL and high-level training at a young age increases the likelihood of DE and there may be a lack of quality nutritional support for these athletes. Thus, multidisciplinary sport science support should be offered at a young age and perhaps also to consider changing the weight rules to prevent the development of the Triad.


Assuntos
Densidade Óssea , Síndrome da Tríade da Mulher Atleta/complicações , Dor Musculoesquelética/etiologia , Esportes/fisiologia , Absorciometria de Fóton , Adulto , Amenorreia/etiologia , Feminino , Síndrome da Tríade da Mulher Atleta/diagnóstico por imagem , Síndrome da Tríade da Mulher Atleta/fisiopatologia , Colo do Fêmur/diagnóstico por imagem , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Oligomenorreia/etiologia , Rádio (Anatomia)/diagnóstico por imagem , Treinamento Resistido , Costelas , Coluna Vertebral/diagnóstico por imagem , Inquéritos e Questionários , Fatores de Tempo , Redução de Peso , Adulto Jovem
14.
J Hum Kinet ; 37: 55-62, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24146705

RESUMO

Twenty-four dance couples performing at the 2011 IDSF (International DanceSport Federation) International Slovenia Open were divided into two groups: the first twelve placed couples (top ranked) and the last twelve placed couples (lower ranked). Video recordings were processed automatically using computer vision tracking algorithms under operator supervision to calculate movement parameters. Time and speed of movement were analysed during single natural (right) and reverse (left) turns performed during the Viennese waltz. Both top and lower ranked dancers tended to perform similar proportionate frequencies of reverse (≈ 35%) and natural (≈ 65%) turns. Analysis of reverse turns showed that the top ranked dancers performed less turns on a curved trajectory (16%) than the lower ranked dancers (33%). The top ranked couples performed all turns at similar speeds (F = 1.31, df = 3, p = 0.27; mean = 2.09m/s) all of which were significantly quicker than the lower ranked couples (mean = 1.94m/s), the greatest differences found for reverse turns (12.43% faster for curved trajectories, 8.42% for straight trajectories). This suggests that the ability to maintain a high speed in the more difficult turns, particularly the reverse turns on a curved trajectory, results in the overall dance appearing more fluent as the speed of movement does not fluctuate as much. This aspect of performance needs to be improved by lower ranked dancers if they wish to improve rating of their performance. Future research should determine which factors relate to the speed of turns.

15.
Int J Sport Nutr Exerc Metab ; 20(5): 418-26, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20975110

RESUMO

Low bone-mineral density (BMD) is associated with menstrual dysfunction and negative energy balance in the female athlete triad. This study determines BMD in elite female endurance runners and the associations between BMD, menstrual status, disordered eating, and training volume. Forty-four elite endurance runners participated in the cross-sectional study, and 7 provided longitudinal data. Low BMD was noted in 34.2% of the athletes at the lumbar spine, and osteoporosis in 33% at the radius. In cross-sectional analysis, there were no significant relationships between BMD and the possible associations. Menstrual dysfunction, disordered eating, and low BMD were coexistent in 15.9% of athletes. Longitudinal analysis identified a positive association between the BMD reduction at the lumbar spine and training volume (p=.026). This study confirms the presence of aspects of the female athlete triad in elite female endurance athletes and notes a substantial prevalence of low BMD and osteoporosis. Normal menstrual status was not significantly associated with normal BMD, and it is the authors' practice that all elite female endurance athletes undergo dual-X-ray absorptiometry screening. The association between increased training volume, trend for menstrual dysfunction, and increased loss of lumbar BMD may support the concept that negative energy balance contributes to bone loss in athletes.


Assuntos
Densidade Óssea/fisiologia , Metabolismo Energético/fisiologia , Vértebras Lombares , Corrida/fisiologia , Adolescente , Adulto , Amenorreia/epidemiologia , Amenorreia/fisiopatologia , Estudos de Coortes , Estudos Transversais , Transtornos da Alimentação e da Ingestão de Alimentos/epidemiologia , Transtornos da Alimentação e da Ingestão de Alimentos/fisiopatologia , Feminino , Humanos , Estudos Longitudinais , Oligomenorreia/epidemiologia , Oligomenorreia/fisiopatologia , Resistência Física/fisiologia , Adulto Jovem
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