This study will explore pregnant women's regular exercise intentions and behavior across trimesters (from first trimester, second trimester to third trimester).

Based on the TPB, this study will explore pregnant women's regular exercise intentions and behavior across trimesters (from first trimester, second trimester to third trimester). Moreover, the study will explore the effect factors, predictors and transition factors regarding pregnant women's regular exercise intention and behavior across trimesters.

Inclusion Criteria:

• Inclusion criteria were women in 8-16 weeks of gestation with a singleton pregnancy who had no obstetric or medical complications

Exclusion Criteria:

• Excluded were those who had American college of Obstetrics and Gynecology (ACOG) absolutely contraindication exercise, such as insulin-dependent diabetes, gestational diabetes, hypertension, and multiple-gestation pregnancies

The participants were recruited from the prenatal outpatient departments of hospitals in Taipei, Taiwan.