Workload Intensity and Rest Periods in Professional Ballet: Connotations for Injury.

Fatigue and overwork have been cited as the main cause of injury with the dance profession. Previous research has shown a difference in workload between professional dancers of different rank, but the role of sex has not been examined. The purpose of this study was to determine workload intensity, rest, and sleep profiles of professional ballet dancers. 48 professional ballet dancers (M=25, F=23) took part in an observational design over 7-14 days using triaxial accelerometer devices. Minutes in METS at different intensities, total time asleep and rest breaks were analysed. Significant main effects for rank (p<0.001) and rank by sex (p=0.003) for total PA, working day activity, post work activity and sleep. Sleep ranged between 2.4-9.6 h per night. All participants spent more time between 1.5-3 METS outside of work. Significant amounts of exercise where carried out outside of their work day, therefore when injury is reported per 1000 h dance activity, this extra-curricular activity might need to be included. When looking at potential causes of injury in dance, a global perspective of physical activity is required that includes activity outside of work and sleep patterns, all activities that influence physiological recovery.

Effects of supplemental training on fitness and aesthetic competence parameters in contemporary dance: a randomised controlled trial.

Within aesthetic sports such as figure skating and rhythmic gymnastics, physical fitness has been shown to have positive benefits on performance outcomes. Presently the link between physical fitness and aesthetic contemporary dance performance has not been demonstrated within an intervention study. In this study, 24 females engaged in contemporary dance (age 27 ± 5.9 yrs; height 165.3 ± 4.8 cm; weight 59.2 ± 7.6 kg) were recruited and randomly assigned to either an exercise (n = 12) or a control group (n = 12). Three dancers withdrew during the study. The intervention group completed a 6-week conditioning programme comprising two 1-hr sessions of circuit and vibration training per week. The circuit training focused on local muscular endurance and aerobic conditioning and vibration training protocol concentrated on power. Repeated measures ANOVA revealed significant increases for the conditioning group in lower body muscular power (11%), upper body muscular endurance (22%), aerobic fitness (11%), and aesthetic competence (12%) (p < 0.05). The control group reported decreases in all the fitness parameters with the exception of aerobic fitness as well as a decrease in aesthetic competence (7%). A 6-week circuit and vibration training programme, which supplemented normal dance commitments, revealed significant increases in selected fitness components and a concomitant increase in aesthetic competence in contemporary professional and student dancers.

Development, validity, and reliability of a ballet-specific aerobic fitness test.

The aim of this study was to develop and assess the reliability and validity of a multi-stage, ballet-specific aerobic fitness test to be used in a dance studio setting. The test consists of five stages, each four minutes long, that increase in intensity. It uses classical ballet movement of an intermediate-level of difficulty, thus emphasizing physiological demand rather than skill. The demand of each stage was determined by calculating the mean oxygen uptake during its final minute using a portable gas analyser. After an initial familiarization period, eight female subjects performed the test twice within seven days. The results showed significant differences in oxygen consumption between stages (p < 0.001), but not between trials. Pearson correlation co-efficients produced a very good linear relationship between trials (r = 0.998, p < 0.001). Bland-Altman reliability analysis revealed the 95% limits of agreement to be ± 6.2 ml·kg(-1)·min(-1), showing good agreement between trials. The oxygen uptake in our subjects equated positively to previous estimates for class and performance, confirming validity. It was concluded that the test is suitable for use among classical ballet dancers, with many possible applications.

Do increases in selected fitness parameters affect the aesthetic aspects of classical ballet performance?

Research has indicated that classical ballet dancers tend to have lower fitness levels and increased injury rates compared to other athletes with similar workloads. The aim of the current study was to examine the effects of a specifically tailored fitness training programme on the incidence of injury and the aesthetic quality of performance of classical ballet dancers compared to a control group. Proficiency in performance was evaluated at the beginning and end of the intervention period for both groups through a 4-min dance sequence using previously ratified marking criteria. The intervention group (n = 8) partook in a weekly 1-hr training session that included aerobic interval training, circuit training, and whole body vibration. All dancers' performance proficiency scores increased from pre-intervention testing to post-intervention. The intervention group's overall performance scores demonstrated a significantly greater increase (p = 0.03) than the equivalent for the control group. It was concluded that supplementary fitness training has a positive effect on aspects related to aesthetic dance performance as studied herein; further research is recommended on a larger and more varied sample. Practical applications from this study suggest that supplemental training should be part of a ballet dancer's regime, and minimal intervention time is required to have observable effects.

Does physical fitness affect injury occurrence and time loss due to injury in elite vocational ballet students?

Most ballet dancers will suffer at least one injury a year. There are numerous causes of injury in dance, and while many investigators have documented risk factors such as anatomical characteristics, past medical history, menstrual history, dance experience, length of dance training, fatigue, and stress, risk factors related to body characteristics and nutrient intake, levels of conditioning, or physical fitness parameters have only recently received the same amount of attention. The aim of the present study was, therefore, to investigate correlations between ballet injury and body fat percentage, active and passive flexibility, lower limb power, upper body and core endurance, and aerobic capacity. Low levels of aerobic fitness were significantly associated with many of the injuries sustained over a 15-week period (r=.590, p=0.034), and body fat percentage was significantly associated with the length of time a dancer was forced to modify activity due to injury (r=-.614, p=0.026). This information may be of benefit to dancers, teachers, physical therapists and physicians in dance schools and companies when formulating strategies to prevent injury.

The demands of a working day among female professional ballet dancers.

Professional classical ballet dancers typically face long working days, and many complain of fatigue, particularly as a possible cause of injury. However, little information exists regarding the true physiological demands on dancers. The aim of the present study was therefore to ascertain the daily workload of professional female ballet dancers in terms of work intensity and rest data. Information regarding a single "work day" was obtained from 51 female dancers in one company using a multiple accelerometer. Data were examined for the amount of time spent at work intensities measured in metabolic equivalents (METS)deemed sedentary, low, moderate, and high, and the length of each period at rest. Results indicated significant differences between dancer rankings (corps de ballet, first artist, soloist, and principal) for mean exercise intensity and the percentage of time spent at sedentary intensity (< 3 METS), moderate intensity (3-6 METS) (p < 0.005), and vigorous intensity (6-9 METS) (p < 0.05). The ratios of time spent below 1.5 METS versus time spent above 1.5 METS ("rest" vs. "work") were also significantly different (p < 0.001) between rankings. When rest periods throughout the working day were analyzed, 90% of dancers were found to spend less than 60 consecutive minutes resting at any one time; for 33.3% of dancers this was less than 20 minutes. Results also revealed significant differences (p < 0.05) between dancer rankings for the greatest amount of rest at any one time during the day. It was concluded that female professional classical ballet dancers' ranking in their companies should be considered in devising work-rest schedules to help them to avoid fatigue and resultant injuries.

Association between selected physical fitness parameters and esthetic competence in contemporary dancers.

The physical demands imposed on contemporary dancers by choreographers and performance schedules make their physical fitness just as important to them as skill development. Nevertheless, it remains to be confirmed which physical fitness components are associated with aesthetic competence. The aim of this study was to: 1. replicate and test a novel aesthetic competence tool for reliability, and 2. investigate the association between selected physical fitness components and aesthetic competence by using this new tool. Seventeen volunteers underwent a series of physical fitness tests (body composition, flexibility, muscular power and endurance, and aerobic capacity) and aesthetic competence assessments (seven individual criteria commonly used by selected dance companies). Inter-rater reliability of the aesthetic competence tool was very high (r = 0.96). There were significant correlations between the aesthetic competence score and jump ability and push-ups (r = 0.55 and r = 0.55, respectively). Stepwise backward multiple regression analysis revealed that the best predictor of aesthetic competence was push-ups (R(2) = 0.30, p = 0.03). Univariate analyses also revealed that the interaction of push-ups and jump ability improved the prediction power of aesthetic competence (R(2) = 0.44, p = 0.004). It is concluded that upper body muscular endurance and jump ability best predict aesthetic competence of the present sample of contemporary dancers. Further research is required to investigate the contribution of other components of aesthetic competence, including upper body strength, lower body muscular endurance, general coordination, and static and dynamic balance.

Video analysis of classical ballet performance.

Video analysis of classical ballet to date has been largely limited to examining the artistic elements of choreography. The aim this study was to employ a method of video analysis to describe the physiological demands of classical ballet performance and to examine differences between artists, soloists, and principal dancers. Forty-eight performances [male = 24, female = 24; artists (corps de ballet) = 16, soloists = 16, principals = 16] were analyzed in four fields: work intensity, body movement, partner work, and number of transitory movements occurring per minute. Statistical analysis revealed significant differences between ranks in two intensity bands: time at rest (p < 0.05) and time performing at moderate intensity (p < 0.05), with soloists and principals resting for 75.2 +/- 15.1% and 53 +/- 24.1% of the total performance, respectively (p < 0.05). Principals also spent a significantly greater percentage of time at moderate intensity than both soloists and artists (p < 0.05). Significant differences between males and females (p < 0.05) were seen in the number of lifting and supporting movements performed. It was concluded that classical ballet is an intermittent form of exercise, utilizing both aerobic and anaerobic energy systems, a finding that supports previous studies. The demands of the performances analyzed varied according to role. Therefore, it was also concluded that video analysis can help provide a basis for rank-specific supplemental training.

Physiological fitness and professional classical ballet performance: a brief review.

Although classical ballet is an artistic expression through the use of the body, there is a real opportunity to improve and extend the dancer's career by simply applying sports science principles to dance training and performance. Dance training is a long process of physical, intellectual, and psychological preparation, through physical exercise, often beginning in childhood and continuing until retirement. Fitness programs, supplementary to traditional dance classes, have only recently been considered as a part of this process; it may be suggested that this cross-training has generally been avoided thus far because of tradition and a reluctance to follow principles associated with sport. Classical ballet training, rehearsal, and performance do not elicit significant stimulus to result in increased aerobic fitness levels. Therefore, dancers often demonstrate low levels of aerobic fitness even though a strong aerobic foundation is necessary to meet the required workload. Dancers have greater than average range of motion and strength at the hip joint but weaknesses in the upper body, torso, hamstrings, and quadriceps. In the past, dancers have been wary of strength training because they perceive this leads to aesthetically undesirable hypertrophy. Dancers also have low body weights and low percentage body fat. Given that training does not provide the opportunity to expend enough energy to maintain these aesthetic demands, this aesthetic demand may be met by caloric restriction, which may lead to subsequent increased injury risk. It has been hypothesized that a "fit for purpose" body can help improve performance, reduce the risk of injury, and ensure prolonged dance careers. This review aims to explore the extent to which physical fitness components relate to dance performance, in particular classical ballet.