Changes in Energy Demand of Dance Activity and Cardiorespiratory Fitness During One Year of Vocational Contemporary Dance Training

Previous literature has demonstrated that the intensity of dance class, as well as its discontinuous nature, is not sufficient to elicit an aerobic training response and that the aerobic capacity of dancers is relatively low. These findings have raised questions of the suitability of training, through class and rehearsal, as adequate preparation for the physical demands of performance and a sustained, successful career in dance. The aim of this study was to describe changes in aerobic fitness and energy cost of dance movement occurring throughout one year of training. Subjects were thirteen female dance students; seven first year undergraduate students (UG), and six postgraduate students (PG). At three time-points (TP1, TP2, TP3) during one academic year each subject completed a treadmill test, to determine VO2peak (ml.kg-1.min-1) and lactate threshold (LT) (ml.kg-1.min-1 and %VO2peak), and a standardised four-minute dance sequence, where mean demand was expressed as VO2 (ml.kg-1.min-1), heart rate (b.min-1), %VO2peak, and %LT. Both groups displayed an overall decrease in mean VO2peak throughout the year, despite a peak in fitness at TP2 in the PG students. No significant changes in LT were noted over time for either group. A significant reduction in the relative intensity of the dance sequence, particularly in relation to mean VO2 (ml.kg-1.min-1) and %LT data, was observed over time in both groups although the degree of change was less in the UG group than the PG group. Apparent adaptations during a rehearsal period in the PG group are presented in contrast to previous research findings. Recommendations for future research include further investigation into the energy demand of rehearsal and cardiorespiratory adaptation during rehearsal periods as well as further reporting of measures related to LT and movement economy

Self-reported symptoms of eating disorders amongst university dance students

Eating disturbances are common amongst female athletes, especially those participating in dance. We investigated the prevalence and correlates of eating disorder risk symptoms amongst female student dancers. Fifty-eight female university dancers completed a self-report measure of eating disorders and eating disorder correlates, along with factors hypothesised to be associated with the concept, including perfectionism and anxiety. Height and body mass were measured to calculate body mass index (BMI). Results indicated that psychological variables correlated positively with eating disorder risk, and that BMI and ineffectiveness were correlates best associated with eating disorder risk for these dancers. Results indicated that the screening of dancers using a self-report measure can help to identify dancers suffering from poor psychological health of which one characteristic is disordered eating. Given the implications of well-being and performance, we suggest that future research should investigate factors associated with eating disorders and that course administrators and health practitioners consider these factors when facilitating and optimising the mental health and performance of dancers

Prevalence and risk factors of dance injury during COVID-19: a cross-sectional study from university students in China

© (2021) The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fpsyg.2021.759413Objectives: Although COVID-19 has transformed dancers’ training environment worldwide, little is known on how this has affected injury prevalence, causes and risk factors. Methods: An online investigation was conducted (September to November 2020) involving Chinese full-time dance students, which covered two 6-month periods just before and during the first COVID-19 lockdown. Results: 2086 students (19 ±2.4yrs) responded. Injury prevalence before lockdown dropped from 39.6% to 16.5% during lockdown (p<0.01). A significant increase in injury severity during lockdown was noted with a 4.1% increase in moderate to severe injuries (p<0.05). During the lockdown, injuries of the lower back, feet and shoulders decreased significantly (p<0.01), but the knees, ankles and groin/hip-joint injuries remained the same. Recurrence of old injury and fatigue remained as the top 2 perceived causes of injury between the two periods with unsuitable floor (p<0.01), cold environment (p<0.05) and set/props (p<0.05) increasing. Students’ fatigue degree decreased (p<0.01) and sleep hours increased (p<0.01) during lockdown. Binary logistic regression analysis indicated that dance injury was associated with fatigue, hours of sleep, and action taken if they suspected an injury during lockdown (p<0.05), but was only related to time set aside for cool-down and age before lockdown (p<0.05). Conclusion: Although the injury prevalence dropped significantly during the first COVID-19 lockdown in Chinese dance students, the main dance injury characteristics remained the same. Decreased fatigue and longer sleep hours could explain the aforementioned drop in injury prevalence during the lockdown.This work was supported by the China Scholarship Council for their financial contribution (D.Y

An investigation of grand battement devant at barre, centre, and in motion using kinematics and electromyography

The purpose of this study was to examine grand battement devant in three conditions: at the barre, in the centre, and traveling. The primary focus was to consider weight transfer in the three conditions, and to examine utilisation of the trunk and lower extremity muscles. An extensive review was done in the dance science literature to determine what previous research had been done related to this subject, and to establish what preliminary work might be needed. As indicated by the literature, in order to achieve this research, it was necessary to develop a dance-specific method for the normalisation of surface electromyography data. In phase one of the research, a dance-specific portable anchored dynamometer was developed and tested. The PAD allowed for the collection of maximum voluntary isometric contractions (MVICs), which could then be used to normalise the sEMG data. In phase two of the research, the grand battement was tested in the three conditions, at the barre, in the centre, and traveling. Forty female dancers volunteered (mean age 30.0 ± 13.0 yrs, mean height 1.63 ± 0.06 m, mean mass 59.0 ± 7.4 kg, and 13.9 ± 13.3 yrs of training in ballet and/or modern dance) and were placed in three groups (Training level): beginner (n = 12), intermediate (n = 14) and advanced (n = 14). Dancers executed five grand battement devant in each of the three conditions (Condition) in randomized order. Data were collected with a 7-camera Vicon motion capture system, two Kistler forceplates, and surface electromyography (EMG), using eight muscles bilaterally. Kinematic data were analysed in three intervals: stance to battement initiation, initiation to battement peak, and peak to end. Four variables were investigated: centre of gravity of the full trunk, centre of gravity of the pelvis, centre of gravity of the upper trunk, and centre of mass. EMG data were analysed in four events: stance, initiation, peak, and end. For weight transfer, the main effect of Condition was significant for all four variables in both the x-axis and the y-axis (p < .001). There were no significant differences for Training and no significant Condition x Training interactions. Muscle use varied according to the combination of event and condition that was executed, and these differences were also influenced by the level of training of the dancer and the side of the body used. It is recommended that dance educators consider the importance of allocating sufficient time to each of the three conditions (barre, centre, and traveling), to ensure development of a variety of motor strategies and muscle activation patterns for dance practice.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Fitness in contemporary dance: a systematic review.

It has been suggested that dancers are less fit compared to other athletes. However, the majority of studies make their arguments based on data deriving mainly from ballet. Therefore, the aim of the current review was to investigate: a) aerobic and anaerobic fitness, muscular strength and body composition characteristics in contemporary dancers of different levels, and b) whether supplementary exercise interventions, in addition to normal dance training, further improves contemporary dance performance. Three databases (Medline, Cochrane and the Cumulative Index to Nursing & Allied Health research database) were searched to identify publications regarding the main fitness components of contemporary professional and student dancers. At a professional level, it appears that contemporary dancers demonstrate higher maximal oxygen uptake and higher scores in muscular endurance than ballet dancers. However, contemporary dance students are equally fit compared to their ballet counterparts and their body composition is also very similar. Only two studies have investigated the effects of supplementary exercise training on aspects of dance performance. Further research is needed in order to confirm preliminary data, which suggest that the implementation of additional fitness training is beneficial for contemporary dance students to achieve a better performance outcome

Changes in Energy Demand of Dance Activity and Cardiorespiratory Fitness During One Year of Vocational Contemporary Dance Training

Previous literature has demonstrated that the intensity of dance class, as well as its discontinuous nature, is not sufficient to elicit an aerobic training response and that the aerobic capacity of dancers is relatively low. These findings have raised questions of the suitability of training, through class and rehearsal, as adequate preparation for the physical demands of performance and a sustained, successful career in dance. The aim of this study was to describe changes in aerobic fitness and energy cost of dance movement occurring throughout one year of training. Subjects were thirteen female dance students; seven first year undergraduate students (UG), and six postgraduate students (PG). At three time-points (TP1, TP2, TP3) during one academic year each subject completed a treadmill test, to determine VO2peak (ml.kg-1.min-1) and lactate threshold (LT) (ml.kg-1.min-1 and %VO2peak), and a standardised four-minute dance sequence, where mean demand was expressed as VO2 (ml.kg-1.min-1), heart rate (b.min-1), %VO2peak, and %LT. Both groups displayed an overall decrease in mean VO2peak throughout the year, despite a peak in fitness at TP2 in the PG students. No significant changes in LT were noted over time for either group. A significant reduction in the relative intensity of the dance sequence, particularly in relation to mean VO2 (ml.kg-1.min-1) and %LT data, was observed over time in both groups although the degree of change was less in the UG group than the PG group. Apparent adaptations during a rehearsal period in the PG group are presented in contrast to previous research findings. Recommendations for future research include further investigation into the energy demand of rehearsal and cardiorespiratory adaptation during rehearsal periods as well as further reporting of measures related to LT and movement economy

Cardiorespiratory profile and performance demands of elite hip-hop dancers: Breaking and new style

Dancers need to constantly maintain and develop their physiological capabilities to support their performances. Previously these physiological demands have been investigated only in traditional dance styles such as ballet and modern. The aim of this study was to examine the physiological demands of two types of hip-hop: new style and break dance. Nine female new style dancers (age 20±6 yrs, height 163.5±1.4 cm, mass 55.8±22 kg) and 9 male break dancers (age 23±4.2 yrs, height 178.2±5.7 cm, mass 62.1±7.7 kg) volunteered for the study. Each subject completed a maximal graded treadmill test and a dance performance routine, either new style (approx 1:45-2:30 min) or breaking (2 min). Breathe-by-breathe gas analysis and heart rate (HR) were collected by a portable gas analyser, and blood lactate (BLa) was measured at the end of the treadmill test and each routine. The male breaker dancers had significantly higher VO2 peak than other equivalent dancers in other genres, whilst the female new style dancers were similar to that previously reported for female dancers. Performance data showed significant differences between the two styles for VO2, HR, and BLa (p<0.001) and for VO2 and HR relative to individual maximal treadmill data (p<0.05). New style is more comparable to other theatrical dance genres, with a lower relative mean VO2 demand, whilst break dance is shorter in duration, allowing a higher cardiorespiratory demand and generating significant levels of blood lactate. This difference is also reflected in the dancers' cardiorespiratory profiles

Effect of vitamin D on muscle function and injury in elite adolescent dancers: A randomized double-blind study

A number of studies have noted low levels of Vitamin D in dancers and this has been associated with increased risk of injuries and decreased muscular strength indices. The aim of the present study was to examine whether vitamin D supplementation over a 4-month period can improve muscle function and injury incidence. Eighty-four participants volunteered, exclusion criteria and drop out (19%) reduced cohort to 67 (f=29, m=38; 17-19yrs). Participants were randomly assigned to either an intervention or placebo group (2:1 ratio). All provided a venous blood sample pre and post the 4-month study period. The intervention group received 120,000IU vitamin D to be taken over a 1-week period and the placebo group received the same number of inert pills. Participants completed a series of muscle function tests pre and post the monitoring period. Injury incidence was recorded by the independent health team at the school. Pre-intervention 6% of the cohort were vitamin D deficient, 81% were insufficient and 13% had sufficient levels; post-intervention 53% were insufficient and 47% were sufficient. The intervention group reported a significant increase in serum 25(OH)D3 (57%; p<0.00) and isometric strength (7.8%; p=0.022) but not muscular power. There was a significant association between traumatic injury occurrence for the intervention and control groups (10.9% vs. 31.8%; p < .02). Vitamin D supplementation decreased the numbers of deficient and insufficient participants within this cohort. The intervention group reported a small significant increase in muscle strength that was negatively associated with traumatic injury occurrence

Influence of Movement Quality on Heart Rate While Performing the Dance-Specific Aerobic Fitness Test (DAFT) in Preprofessional Contemporary Dancers.

To explore whether movement quality has influence on heart rate (HR) frequency during the dance-specific aerobic fitness test (DAFT). Thirteen contemporary university dance students (age 19 ± 1.46 yrs) underwent two trials performing the DAFT while wearing a Polar HR monitor (Kempele, Finland). During the first trial, dancers were asked to perform the movements as if they were performing on stage, whereas during the second trial, standardized verbal instructions were given to reduce the quality of movement (e.g., no need to perform technically correct pliés). The variables measured at each trial were HR for all five stages of the DAFT and HR recovery (1 and 2 min after finishing the DAFT), movement quality (MQ) score, and rate of perceived exertion score (RPE). There were significant differences in HR between Trial 1 and Trial 2. For all stages and the resting period, HR was lower during Trial 2 (p<0.001). Also, the RPE score was significantly lower and the MQ score was significantly higher, indicating a poorer performance, during Trial 2 (both p<0.001). The results suggest that DAFT performance with lower movement quality elicits lower HR frequency and RPE during the DAFT. We recommend that specific instructions be given to participants about executing the movement sequence during the DAFT before testing commences. Also, movement quality must be taken into account when interpreting HR results from the DAFT in order to distinguish if a dancer's low HR results from good aerobic fitness or from poor performance of the movement sequence

Ballet injuries: injury incidence and severity over 1 year.

STUDY DESIGN: Prospective, descriptive single-cohort study. OBJECTIVE: To assess the incidence and severity of injuries to a professional ballet company over 1 year. METHODS: Data for an elite-level ballet company of 52 professional dancers were collected by an in-house medical team using a time-loss injury definition. RESULTS: A total of 355 injuries were recorded, with an overall injury incidence of 4.4 injuries per 1000 hours (female, 4.1; male, 4.8; P>.05) and a mean of 6.8 injuries per dancer (female, 6.3; male, 7.3; P>.05). Mean injury severity was 7 days (female, 4; male, 9; P.05); mean severity of injury was 3 days for females and 9 days for males (P<.05). The percentage of traumatic injuries was 32% for females and 40% for males (P<.05); the corresponding severity was 6 and 10 days, respectively (P<.05). CONCLUSION: The relatively high number of injuries reported and the resulting loss of dance time support the need to introduce interventions to reduce the risk of injury in professional dancers