A time-motion analysis of turns performed by highly ranked Viennese waltz dancers

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

Bone mineral density, rib pain and other features of the female athlete triad in elite lightweight rowers

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

A mixed methods approach to advance the understanding of physical activity behaviour during pregnancy

An active pregnancy encompasses benefits that apply to both mother and baby. However, before investing resources in interventions aimed at changing or supporting expectant mothers’ physical activity behaviours, it is necessary to have a greater fundamental understanding of the modifiable factors influencing women’s decisions during this time. Therefore, the main purpose of this study was to investigate the socio-cognitive determinants of physical activity during pregnancy. A mixed methods research approach using a multiphase design framed by the Theory of Planned Behaviour (TPB; Ajzen, 1991, Organizational Behavior and Human Decision Processes, 50, 179-211) guided the investigation. Following ethical approval and permission to carry out the study, participants were recruited from randomly selected antenatal clinics in the East Kent region of England. Application of the TPB required both qualitative and quantitative cross-sectional data to be collected. Study One (n = 18) involved the elicitation of pregnant women’s beliefs towards being physically active. The modal salient behavioural, normative and control beliefs were used to inform the development of a TPB questionnaire which was implemented during the next phase of the investigation. Study Two (n = 78) examined the predictive utility of the TPB in explaining pregnant women’s physical activity intentions and behaviour and scrutinised the role of past behaviour within this context. Finally, Study Three (n = 10) comprised semi-structured interviews involving community midwives. Meta-inferences maintained the function of improving the validity of the study and advancing the overall aim of the research project. Specifically, triangulation was used to ascertain convergence, corroboration, and correspondence of findings between studies. Whilst results of the individual studies hold merit, meta-inferences point towards the development of three main themes: (1) pregnant women lack access to the necessary information that would allow them to make informed decisions regarding their engagement in physical activities; (2) a co-ordinated effort involving interprofessional collaboration is required to support pregnant women in overcoming barriers associated with regular physical activity participation; and (3) profiling pregnant women according to motivation and behaviour status could serve as a useful and manageable starting point for intervening to produce positive changes in pregnant women’s physical activity behaviour. In normalising physical activity during pregnancy and achieving better health outcomes for mothers and babies, it is necessary to consider the modifiable factors involved in behaviour change, identify opportune moments to intervene, and involve a network of professionals in facilitating and supporting pregnant women’s engagement with physical activities

Caffeine increases strength and power performance in resistance‐trained females during early follicular phase

The effects of 4 mg·kg‐1caffeine 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, were 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

Competition intensity and fatigue in elite fencing

As yet, no studies have characterised fencing competitions. This was investigated in nine elite male foilists across two competitions, where countermovement jump (CMJ) height, testosterone (T), cortisol (C), alpha-amylase (AA) and immunoglobulin A (IgA), were obtained. Heart rate (HR) was measured throughout competitions and blood lactate (BL) and rating of perceived exertion (RPE) were measured post bouts. Average (± SD) scores for RPE, BL and HR (average, max and percentage of time ≥ 80% HRmax) were highest in the knockout bouts compared to 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 bpm, 195 ± 7 vs. 192 ± 7 bpm, 74 vs. 68%) however, only significant (p .05), increased throughout competition and dropped thereafter. While 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 HR’s appear possible on account of ample within and between-bout rest. The small competition load associated with fencing competitions may explain the non-significant findings found

A retrospective investigation on age and gender differences of injuries in DanceSport

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