Research requires planning but also reflection, which is necessary before, during, and after finishing a study. This case study analyzes the methodology of a randomized controlled trial with an exercise-based intervention addressed to improve the psychological health of pregnant women. The case study provides details on our research design and the intervention, as well as our use of intention-to-treat analysis and per-protocol analysis to determine the effects of the intervention.
The reader will find useful tools to measure physical activity level through validated methods, resources to comply with the principle of reproducibility through the required steps in exercise-intervention designs, and information sources for the absolute and relative contraindications to exercise during pregnancy as well as safe and unsafe physical activities. In addition, methodological changes and possible strategies to achieve a high adherence to an intervention and to improve study engagement are proposed.