The World Health Organization recommends that children accumulate at least 60 minutes of moderate-to-vigorous-intensity physical activity (MVPA) daily. However, knowledge about the association between physical activity (PA), physical fitness and body mass index (BMI) among elementary school children in the Arctic is limited.
PURPOSE: To examine the association between PA levels, physical fitness and BMI in elementary school children in Northern Norway.
METHODS: Elementary school children in 1st, 3rd, 5th and 7th grade were recruited to wear an accelerometer (wGT3X-BT, ActiGraph, LLC, Pensacola, United States) for seven consecutive days (n=216). PA was categorized according to intensity, and dichotomized into reaching the PA recommendations or not. Physical fitness was measured by using Test of Physical Fitness (Fjørtoft et.al. 2011) consisting of a nine-item compound motor activity score that includes various combinations of endurance, strength, agility, balance, and motor coordination, which is calculated as total physical fitness based on z-scores. BMI (kilogram/height 2) was used as body composition measure.
RESULTS: In total, 94 (43%) of 216 the children reached the recommendation of 60 min MVPA per day. There was a significant difference (p<0.001) in total physical fitness score between boys (3.01) and girls (-2.35). A positive association between physical fitness score and reaching the PA recommendations was observed in 3rd, 5th and 7th grade (p<.05). BMI was inversely associated with physical fitness in 5th and 7th grade (p<0.05) but not in 1st and 3rd grade. There was no significant association between those who achieved the PA recommendations and BMI.
CONCLUSION: Children in elementary school who reach the recommendations for PA seem to have a higher score on the physical fitness test, except for the first graders. BMI was not related to physical fitness or reaching PA recommendations except an inverse association between BMI and physical fitness in higher grades.