Walking Program of Low or Vigorous Intensity During Pregnancy Confers an Aerobic Benefit

Abstract

Walking is the most popular activity during pregnancy and may confer an aerobic benefit. However, the minimum intensity threshold of a maternal walking program for an aerobic conditioning response is unknown. The purpose was to examine the effect of a walking program of a low-intensity (LI, 30% heart rate reserve, HRR) or vigorous-intensity (VI, 70%HRR) on maternal cardiorespiratory responses to a standard submaximal treadmill test. Normal weight pregnant women were randomized at study entry (16-20 weeks of gestation) to the LI (n=23) or VI (n=21) walking program, with nutritional control. Participants performed a steady-state treadmill exercise test at their prescribed intensity pre- and post-intervention (34-36 weeks) to evaluate changes in cardiorespiratory responses. Increasing body mass due to pregnancy was similar between the groups throughout the study. From pre- to post-intervention, relative (mL kg - 1 min - 1) VO2 and VCO2 during steady-state submaximal treadmill exercise did not change in the LI group but decreased in the VI group (- 1.25±2.71, p=0.02 and - 1.50±2.64, p=0.005, respectively). Both groups presented increases in oxygen pulse (p≤0.002). Our results showed that the energy cost of walking was not affected by the increase in maternal body weight in the LI group and was decreased in the VI group, suggesting an aerobic conditioning response in both groups, although the VI group presented a greater response. All women presented similar body mass throughout the intervention and delivered healthy babies, indicating that a prenatal walking program of low or vigorous intensity, combined with healthy eating habits, is safe and beneficial to the mother and fetus.

Physical Activity Patterns and Factors Related to Exercise during Pregnancy: A Cross Sectional Study

“…There is no contraindication from its practice during pregnancy, except for the general contraindications for exercise during pregnancy [6]. Several clinical trials have used walking as an intervention to assess the effects of exercise on maternal and perinatal outcomes and have found it to be an effective intervention [31–34]. …”

An active pregnancy for fetal well-being? The value of active living for most women and their babies

“…For women who are unaccustomed to physical exertion and may be less inclined to engage, recent evidence suggests that yoga12 is a viable exercise modality and that a simple walking programme of both low or vigorous intensity during pregnancy confers an aerobic benefit 13. Given the strong association between aerobic fitness and all-cause mortality14 engaging in non-sedentary pursuits during gestation may be of tremendous value to limit disease and mortality risk later in life.…”

Components of Exercise Prescription and Pregnancy

“…13 Even mild walking of 30% (peak aerobic capacity) will improve fitness levels in sedentary women continued throughout pregnancy. 3 Recording daily step counts by wearing a pedometer may motivate sedentary pregnant women to become physically active by setting a goal to work up to 10,000 steps per day. 20 Starting at 25 minutes per walking session, adding 2 min/ session each week until reaching 40 minutes and then maintaining until delivery, has been shown to achieve 10,000 steps in overweight and obese pregnant women.…”

“…Exercise has been shown to be safe for mother and fetus with many benefits for women with uncomplicated pregnancies. 2 These benefits include improved fitness, 3 prevention of excessive gestational weight gain, 4 obesity/weight retention, 5 gestational diabetes, 6 hypertension, 4 maternal depression, 7 and reduction in cesarean section rates. 4 Furthermore, maternal exercise has been linked to appropriate fetal weight gain 8 and prevention of chronic disease development in the offspring.…”