Relationship Between Different Bouts Of Physical Activity And Physical Fitness In Preschool Children

Abstract

PURPOSE: To examine the relationship between bouts of physical activity and physical fitness in preschool children. METHOD: Sporadic sessions (2-4 seconds) of moderate-to-vigorous physical activity (MVPA), short bouts (5-9 seconds) of MVPA; and medium-to-long bouts (≥10 seconds) of MVPA were measured over 7 days using ActiGraph GT3X accelerometers. Physical fitness was assessed by a 20-meter multistage shuttle run test (cardiorespiratory fitness), handgrip and standing long jump tests (musculoskeletal fitness), and the 2×10-meter shuttle run test (speed/agility). A composite score of physical fitness was created from the mean of the standardized values of all physical fitness tests. The bouts of physical activity and composite scores were categorized into quartiles (Q1-Q4 group) by sex; the highest quartile (Q4) of composite scores were assigned as high healthy fitness (HPF). Logistic and linear regression were used to investigate the relationship between bouts of MVPA and HPF. RESULTS: A total of 265 participants were included in the final statistical analysis (boys, 149; girls, 116; 57.19 ± 5.33 months). After adjusting for confounding factors, relative to Q1, the odds ratios (OR) for a HPF in Q4 were 11.72 (95% CI=2.27- 60.53), 7.53 (95% CI=1.83-30.90) and 8.98 (95% CI=1.78-45.39) for sporadic MVPA, short bouts and medium-to-long bouts of MVPA in boys, respectively. Similar results were allow observed in girls, 11.85 (95% CI=2.33-60.19), 12.34 (95% CI=2.47-61.57) and 8.58 (95% CI=1.70-43.41), respectively. There was a non-linear relationship between overall MVPA and HPF in boys. When the total MVPA ≤ 65 min/day, the OR of achieving HPF increased by 17% (OR = 1.17, 95% CI = 1.02-1.35) for every 1 minute/day increment in total MVPA; no increases in HPF with increased MVPA were observed for >65 min/day. This non-linear relationship was not found in girls. CONCLUSION: There is a significantly positive relationship between bouts of MVPA and HPF in preschool children. To achieve HPF in preschool children, it is recommended that boys accumulate total MVPA 65 minutes or longer every day. Supported by National Natural Science Foundation of China (81703252)