Metabolic and hormonal responses to low-impact aerobic dance during pregnancy

This study examined the plasma glucose, free fatty acids (NEFA), lactate, triglyceride, cortisol, and insulin responses of pregnant women (22-28 wk) to a 40-min aerobic dance program and 40-min treadmill walking at similar heart rate intensities. The heart rates during exercise averaged 135 ± 5 bt-min^{- 1} for both trials. Immediate post-exercise plasma glucose levels were lower than resting levels for both exercise trials (P < 0.05), and remained below resting levels 20 min after exercise. Plasma triglycerides and NEFA were increased immediately post-exercise (P < 0.05), and returned toward rest 20 min after exercise. The NEFA responses at the end of the walking trials were significantly greater than at the end of the aerobic dance trials (P < 0.05). For both trials, immediate post-exercise plasma insulin levels were below resting levels (P < 0.05) and remained attenuated 20 min post-exercise. Plasma cortisol concentrations were unchanged throughout the aerobic dance trial. However, a mean increase of 105 nmol · l^-1 immediately post- exercise was evident during the walking trials (P < 0.05). The results suggest that 40 min of walking or aerobic dance reduces blood glucose but does not cause hypoglycemia. Further, the results suggest that 40 min of walking or aerobic dance does not expose the mother to serious metabolic consequences that might adversely affect the fetus.