Physical Fitness, Physical Activity and Sedentary Activities of 7 to 11 Year Old Boys with Different Body Mass Indexes

Purpose: The purpose of this study was to examine the differences in physical fitness, physical activity, and sedentary activities among 7 to 11 year old boys with varying body mass index in Ardabil, Iran. Methods: The sample consisted of 766 boys who participated in eight weight bearing (1 mile walk/run, sit ups, standing long jump, vertical jump, shuttle run 4 × 10 m, 30-meter sprint, pull ups, pushups) and four non-weight-bearing physical fitness tests (flamingo balance, handgrip; sit and reach and finger reaction time). Physical activity and sedentary activities were assessed by questionnaires. Body mass index (BMI) was computed to classify participants into normal weight, underweight, overweight and obese groups. Results: The prevalence of underweight, overweight and obesity was 10.7%, 14.1% and 4.2% respectively. Cardiorespiratory fitness (VO2max) decreased progressively as the BMI increased and differences among the all body mass index categories were significant (P<0.01). Obese subjects performed worse in all weight bearing fitness tests than normal weight subjects (P<0.01). Moreover, overweight subjects performed worse in one mile, pushups and pull ups than normal weight subjects (P<0.01). Underweight subjects had significantly lower Pushups than normal weight subjects (P<0.01). Obese subjects had significantly higher sedentary activities and lower physical activity than other counterparts (P<0.01). Conclusions: This study showed that weight bearing physical fitness, cardiorespiratory fitness and physical activity progressively decreased as the BMI increased and conversely, sedentary activities increased as the BMI increased.