Relationship of Physical Fitness and Body Composition in the Incidence of Hypertension Among School-Aged Children and Youth in the North of Portugal

The purpose of this study was to analyse the relationship of physical fitness and body composition to blood pressure (BP) in school-aged children and youth from 12 to 18 years old. Ninety-one male and female students were evaluated on the following: systolic blood pressure (SBP), diastolic blood pressure (DBP), body mass index (BMI), waist circumference, body fat percentage, and five independent FITNESSGRAM® physical tests (shuttle-test, curl-ups, push-ups, shoulder-stretch, and sit-and-reach). There were significant associations between shoulder stretch and SBP from 17 to 18 years (p = 0.012), and between BMI and SBP in ages 14 to 18 years (p < 0.05). Changes in SBP were related to curl-ups in ages 17 to 18 years (r2 = 0.37), and to BMI in ages 14 to 16 years (r2 = 0.29), and 17 to 18 years (r2 = 0.34). Changes in DBP were related to BMI in ages 14 and 16 years (r2 = 0.55), and 17 to 18 years (r2 = 0.22). Physical fitness levels exhibited a minor influence on BP; in contrast, high BMI is consistently associated with high BP in ages 14 through 18 years.