Ballet dancers are reported to have an increased risk for energy deficiency with or without disordered eating behavior. A low ratio between measured (m) and predicted (p) resting metabolic rate (RMRratio < 0.90) is a recognized surrogate marker for energy deficiency. We aimed to evaluate the prevalence of suppressed RMR using different methods to calculate pRMR and to explore associations with additional markers of energy deficiency. Female (n = 20) and male (n = 20) professional ballet dancers, 19–35 years of age, were enrolled. mRMR was assessed by respiratory calorimetry (ventilated open hood). pRMR was determined using the Cunningham and Harris–Benedict equations, and different tissue compartments derived from whole-body dual-energy X-ray absorptiometry assessment. The protocol further included assessment of body composition and bone mineral density, blood pressure, disordered eating (Eating Disorder Inventory-3), and for females, the Low Energy Availability in Females Questionnaire. The prevalence of suppressed RMR was generally high but also clearly dependent on the method used to calculate pRMR, ranging from 25% to 80% in males and 35% to 100% in females. Five percent had low bone mineral density, whereas 10% had disordered eating and 25% had hypotension. Forty percent of females had elevated Low Energy Availability in Females Questionnaire score and 50% were underweight. Suppressed RMR was associated with elevated Low Energy Availability in Females Questionnaire score in females and with higher training volume in males. In conclusion, professional ballet dancers are at risk for energy deficiency. The number of identified dancers at risk varies greatly depending on the method used to predict RMR when using RMRratio as a marker for energy deficiency.
Sarah Staal, Anders Sjödin, Ida Fahrenholtz, Karen Bonnesen and Anna Katarina Melin
Mette S. Nielsen, Jonas S. Quist, Jean-Philippe Chaput, Stine-Mathilde Dalskov, Camilla T. Damsgaard, Christian Ritz, Arne Astrup, Kim F. Michaelsen, Anders Sjödin and Mads F. Hjorth
Inflammatory markers, adiponectin, and movement/nonmovement behaviors have all been linked to risk factors for cardiovascular disease; however, the association between childhood movement/nonmovement behaviors and inflammatory markers and adiponectin is unknown.
We explored the association between accelerometer determined moderate-to-vigorous physical activity (MVPA), sedentary time, and sleep (7 days/8 nights) and fasting C-reactive protein (CRP), interleukin-6 (IL-6), and adiponectin in 806 school children. A sleep variability score was calculated.
MVPA was negatively associated with adiponectin in boys and girls (P < .001) and with CRP and IL-6 in girls (P < .05) independent of sleep duration, sedentary time, age, fat mass index (FMI), and pubertal status. Sedentary time was positively associated with adiponectin in boys and girls (both P < .001), and sleep duration with adiponectin in boys independent of age, FMI, and pubertal status (P < .001); however, these associations disappeared after mutual adjustments for movement behavior. Sleep duration variability was positively associated with CRP in girls independent of all covariates (P < .01).
MVPA remained negatively associated with inflammatory markers and adiponectin, and sleep duration variability positively associated with CRP after adjustment for FMI, pubertal status, and other movement behavior. The inverse association between MVPA and adiponectin conflicts with the anti-inflammatory properties of adiponectin.