The present study was designed to develop and validate a prediction equation for peak oxygen consumption (V̇O2peak) using a progressive treadmill test and to refine the current target HR exercise guidelines for pregnancy (PARmed-X for Pregnancy).Methods:
One hundred fifty-six women between 16 and 22 wk of gestation performed the test to volitional fatigue (peak exercise test). Data from every fourth subject were used to form the cross-validation group. The women were separated into two age groups; 20-29 (N = 60) and 30-39 (N = 96) yr of age and then further separated into fit (V̇O2peak at the top 25th percentile), unfit (V̇O2peak at the bottom 25th percentile), and active (between these two ranges). HR and V̇O2peak values were used in the regression equation to predict target HR ranges at 60 and 80% V̇O2peak.Results:
The prediction equation (R2 = 0.72, R2adjusted = 0.71 and SEE = 2.7) was compared with cross validation (N = 39; P = 0.78). Fit women had a V̇O2peak ≥ 27.2 mL·kg−1·min−1 and ≥ 26.1 mL·kg−1·min−1 for ages 20-29 and 30-39 yr, respectively, representing the top 25th percentile. Unfit women had a V̇O2peak of ≤ 21.0 mL·kg−1·min−1 and ≤ 19.6 mL·kg−1·min−1, respectively, representing the bottom 25th percentile. HR/V̇O2peak regression lines for each fitness level were used to generate the target HR zones in each age group.Conclusion:
This is the first study to provide a validated prediction equation of V̇O2peak for pregnant women using a progressive treadmill exercise test. The defined target HR zones based on age and the appropriate fitness levels can be used for exercise prescription in healthy pregnant women.