PROS:

�Can establish cause and effect. Through the use of this study design, investigators are able to determine if physical inactivity lead to the disease or health outcome of interest.

�Can directly measure the development of disease or condition of interest in both those who do and do not participate in physical activity.

CONS:

�Not a good study design for studying rare diseases or conditions because the investigators have to wait for individuals to develop the disease or condition of interest.

�Can be costly and time-consuming

�Often requires a large sample size to ensure that enough study participants will develop the disease or outcome of interest during the course of the study.

�This study design is subject to participants dropping out or being loss to follow-up (can�t be found) because of the lengthy study time.

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