The effectiveness of a ‘short, sharp, shock’ high intensity exercise intervention in 11- and 12-year-old Liverpool schoolgirls

Objective: Girls are consistently reported as being less physically active than boys, and physical activity declines substantially in adolescence. The aim of this pilot study was to assess the effect of a novel, high intensity dance intervention on various health measures, and determine compliance to the intervention in 11- and 12-year-old schoolgirls. Design: Sixteen participants (mean age = 11.79 0.3 years, BMI = 22.67kg/m2) were randomly assigned to either a control or an intervention group. All participants completed baseline and retest measures, including assessments of habitual physical activity (accelerometry), body composition and bone health (DEXA), anthropometrics, cardiorespiratory fitness (VO2peak), and cardiovascular measures (left ventricular mass, carotid intima-media thickness, blood pressure). The intervention group completed a three-week high-intensity dance-based intervention consisting of four sessions of 6 × 30 second bouts of high intensity activity. Intensity was monitored using heart rate. Results: The mean completed intervention time was 28.1minutes out of a possible 36minutes (78%). The mean % HR max values of 94.2%, 93.7%, and 96.8% were achieved for intervention weeks 1, 2 and 3, respectively. Results described non-significant improvements in body mass, waist and hip circumferences, fat mass, trunk fat, VO2peak, MVPA and step counts in the intervention group. The control group displayed some non-significant increases in measures of adiposity, including body mass, waist circumference, fat mass and trunk fat. Conclusions: Findings suggest that the intervention had some impact on body mass maintenance and was well tolerated by participants. The intervention warrants further investigation with larger participant groups.