Certain periods in women's life, such as pregnancy and afterwards, expose them naturally to a greater reduction of physical activity than men. Many researchers have realized that exercise during pregnancy is associated with "improved quality of life, depression, self-confidence, increase and a positive mental image of the body, weight control during pregnancy, and pain reduction" (1). Previous studies have shown that women who have given birth have less activity than women of the same age who did not have pregnancy experience (2).
During the pregnancy period, 80% of women experience some degrees of psychosocial stress for adaptive behavior and 20% suffer from severe mental disorders (3). Hypertension is also observed in 20% of first pregnancies. Hypertension composes the second cause of mortality. In severe preeclampsia, the perinatal mortality rate rises to 60%. Exercise by helping speed up blood flow in the lower extremities and preventing it from stopping, prevents deep vein thrombosis. In addition, a high prevalence of depression up to 60% has been reported in developing countries, and due to the low index of physical growth, physical activity will lead to a positive effect on depression (4). In developing countries, one woman in 3–5 women have major mental health problems during pregnancy period and post-delivery, while this ratio is about one in ten in developed countries (5). In line with the Third Millennium Development Goals and based on an international commitment from 1990 to 2015, many countries, including Iran, have been committed to taking steps to reduce the mortality rate of mothers. On the other hand, it should be known that improving the conditions for normal delivery is a fundamental step to promote the health of mothers in the country (6). The lack of mobility and physical activities during pregnancy period increase the probability of placenta Previa, diabetes, hypertension, the probability of cesarean section and so on in women (7). A meta-analysis in 2015 shows that regular exercise during pregnancy period on average is associated with an increased likelihood of a normal delivery (8).
Physical activity as any movement and mobility of the body that is done by skeletal muscles and by consuming energy, should not be confused with exercise and includes activities such as playing, walking, doing housework, gardening, dancing, and so on (9). The American College of Obstetricians and Gynecologists and the Center of Disease Prevention recommends healthy pregnant women to follow standard exercise programs. The American Association of Obstetricians and Gynecologists (ACOG) stated in 2002 that pregnant women, in the absence of medical and obstetric disorders, could perform physical activities most days of the week that has no potential side effects for the fetus and does not create direct harm to the mother's abdomen with medium intensity and with a limited time of about 30 minutes (10). Proper and adequate physical activity during pregnancy period has a significant effect on the health of the mother and the fetal growth process. It has been shown that physical activity affects prenatal outcomes; however, physical activity parameters such as type, severity, and length of pregnancy may vary. Doing these, exercises can have beneficial effects on the health of the mother and fetus (9). Among these effects, cases such as reducing the prevalence of HTN, eclampsia, and preeclampsia can be mentioned. Exercising prevents deep vein thrombosis by speeding up blood flow in the lower extremities and preventing them from stopping. Physical readiness allows pregnant women to perform types of their daily family, job and entertainment activities. Therefore, the risk of physical diseases due to low mobility is also reduced (11). Exercise reduces the severity of pain, even during the process of delivery and improves heart and lung function. The high percentage of cesarean sections may have cultural, economic, occupational or physical reasons (12).
Studies have shown that primiparous women who have performed aerobic exercises at least 3 sessions a week and each week, 30 minutes during pregnancy have lower overweight, have a shorter pregnancy period, and a lighter newborn baby. A common misconception related to pregnancy period is that physical activity and exercise during pregnancy period are problematic and rest is the best solution (13). Contrary to this wrong belief, it should be noted that if the principles related to scientific exercise prescription were observed, it would be very valuable during pregnancy period. The goal of physical activity during pregnancy period is to maintain or increase physical readiness (not to increase athletic abilities) (13).
The shortage of physical activity is considered as a great risk factor for cardiovascular diseases, obesity-related diseases and mortality. Certain periods in women's life, such as pregnancy period, will naturally lead to a greater reduction of physical activity. Many researchers have concluded that exercising during pregnancy period is associated with "the quality of life improvement, depression reduction, and self-confidence, increase, and weight control during pregnancy” (14).
What is certain is that nowadays in health education, effective interventions are performed based on theory and model. It has been specified that theory-based physical activity interventions are preferable to non-theory-based interventions. Theories and models are considered as a basis for interventions and through them the effects of intervention can be measured and behaviors can be predicted. Theory is a set of interrelated concepts, definitions, and propositions that provide a systematic view of events or situations by specifying relationships between variables in order to explain and predict events and situations. Theories help us to express explicit assumptions and hypotheses related to intervention strategies and objectives (15).
Healthy mothers are advised to perform moderate-intensity physical activity for at least 150 minutes per week during pregnancy period. The prevalence of obesity during childhood and infancy periods has increased dramatically over the past three decades, and mortality rate has increased in the post-delivery period due to obesity (7).
Unfortunately, despite the many benefits of exercise in physical and mental health, many people do not have enough physical activity (3). Active participation in physical activity during pregnancy period not only maintains the general health of the pregnant person, but also reduces the risk of chronic diseases such as gestational diabetes and preeclampsia. However, the relationship between physical activity during pregnancy period and the risk of PTB is still unclear, because there are also other effective factors that affect premature delivery (3). LMS distance learning systems is considered as a tool for continuous education, and these trainings can include teachers and students of any age, geographical location, social and political status and position and with any type of training. E learning is a new method of distance learning, and is based on the internet network. With this description, people who have limited time such as employees and managers, experts, engineers and staff or due to geographical problems do not have access to good professors like residents of small or remote sites can make the maximum use of E-learning opportunities. Researches show that virtual academic education is a successful and efficient system, if the educational content is properly compiled and properly evaluated (16). Considering the low costs of this type of education, the foundation policy of using it has been proposed in Iranian university education. Also, considering that no study with a qualitative approach has been conducted so far in Iran about the underlying factors of physical activity in pregnant women, so the findings of this research can be the basis and foundation for physical activity development programs in pregnant women in the future of the country. The results of this investigation can lead to making the necessary decisions and planning for the implementation of more comprehensive educational methods based on the conditions and facilities of the educational environment.