Effect of aerobic dance on cardiorespiratory fitness in pregnant women: a randomised controlled trial.

To evaluate the effectiveness of aerobic dance on cardiorespiratory fitness in pregnant women.Randomised controlled trial.Sixty-two primiparous women with a mean age of 30.6 [standard deviation (SD) 3.7] years randomised to exercise (n=34) and (n=28) control groups.Two aerobic dance classes per week and 30 minutes of daily self-imposed physical activity for 12 weeks.Cardiorespiratory fitness, assessed using a submaximal treadmill test to establish oxygen uptake (VO2) (ml/kg/minute) at three different levels of blood lactate. Levels 1, 2 and 3 were calculated and defined as 0.5, 1.0 and 1.5 mmol/l above resting blood lactate level, respectively.The women in the exercise group attended a mean of 20 (SD 12) out of 24 aerobic dance classes. Both groups had a small significant decrease in VO2 between baseline and post-intervention: the exercise group decreased from 25.8 (SD 3.3) to 24.5 (SD 3.8) ml/kg/minute and the control group decreased from 25.8 (SD 3.1) to 24.5 (SD 2.5) ml/kg/minute at Level 3 (anaerobic threshold) (mean difference in change at Level 3=0.1, 95% confidence interval -1.4 to 1.7; P=0.89). There were no differences in change between the groups at any level.A 12-week aerobic dance programme had no effect on cardiorespiratory fitness in pregnant women.