Primary Objective: To compare the effect of 6 months healthy physical activity on blood pressure in female school children (9-13 yrs) with those who have routine physical activity~Secondary objective: To compare the effect of 6 months of healthy physical activity on body mass index and maths scores with those who have routine physical activity~Study Design: It would be a non-randomized experimental study (community intervention trial). It is designed to test the effectiveness of exercise on reducing blood pressure and the effect on BMI and maths scores~Setting: The study would be conducted in 4 public sector schools in Karachi.~Study Population: The study population would be selected from 4 local public sector schools near our hospital, The Aga Khan University Hospital. Two schools would have intervention and 2 schools would serve as controls. Both groups would have a base line screening for the outcome variables and then at 6 months~Intervention: The intervention is 30 minutes of healthy physical activity; 4-times/week would be carried out for a period of 6 months. This would be carried out by certified physical trainers who are experts in training children in aerobic exercise. Intervention group will have half an hour session on exercise motivation and its benefits. The routine activity group will have a similar session at baseline.~Sampling technique: convenience sampling~Sample Size : A sample size of 126 (63 in each arm) achieves 80% power to detect a difference of 4.3 mm in systolic blood pressure between the null hypothesis mean of 110.3 and an alternative hypothesis mean of 105.7 with an estimated standard deviation of 9.7 and with significance level (alpha) of 0.05 using one sided one sample t test. Assuming that there could be a 10% dropout rate we plan to take a total sample size of 140 students. We multiplied the total sample size by 2 to account for the design effect between clusters (schools) and achieved a total sample size of 280 that is 140 in each arm.~Dependent variables or outcome variables: Primary outcome measure would be the blood pressure. Secondary outcome measures would be body composition including weight, BMI, central obesity, and maths score. Independent variable would be demographics (age, school class) and the intervention of healthy physical activity and measurement of food intake frequency
Healthy physical activity decreases blood pressure in young female school children. It also has effects on BMI and maths scores.