Background: A systematic review was performed to identify the types of physical activities effective as interventions in preventing metabolic syndrome in middle-aged women. Methods: Electronic databases (MEDLINE, EMBASE, the Cochrane Library, and CINAHL) served as the data sources. Cochrane's Risk of Bias 2 was applied to assess the risk of bias of the randomized controlled trials. Meta-analyses were performed on selected studies using Review Manager 5.3. Thirty-one trials enrolling 2,202 participants were included. Results: Compared to controls, the effects of physical activity were indicated by pooled mean differences, which were -0.57 kg for body weight, -0.43 kg/m2 for body mass index, -1.63 cm for waist circumference, -4.89 mmHg for systolic blood pressure (BP), and -2.71 mmHg for diastolic BP. The effects were greater on the measurements of waist circumference and BP than on body weight and BMI. The types of physical activities were further analyzed according to sub-groups. Only aerobic exercise did not affect body weight and resistance exercise did not significantly change any results. Contrarily, combined exercises significantly reduced measurements of waist circumference and BP. Conclusion: This review can provide valuable information for research and implementation of measures to prevent metabolic syndrome in middle-aged women.