Teun Remmers

Relationship between PA enjoyment and PA in children | 41 Table 1. Descriptive characteristics of the study sample. Boys Girls n Mean (SD) n Mean (SD) Age (years) 80 9.2 (0.6) 91 9.1 (0.7) Recruitment group (% alternative) 5 6% 9 10% Low maternal education 8 10% 9 10% Mid-low maternal education 25 31% 35 39% Mid-high maternal education 44 55% 45 50% High maternal education 3 4% 2 2% PACES mean (1.00 – 5.00) 80 4.2 (0.3) 91 4.2 (0.4) PACES (below median ≤ 4.2857) 36 45.0% 38 41.8% Days of PA measurement 80 6.7 (1.0) 91 6.5 (0.9) % time spent active per day 80 49.8 (5.0) 91 48.0 (4.4) % time spent in light PA per day 80 39.9 (3.4) 91 39.7 (3.3) % time spent MVPA per day 80 10.0 (2.9) 91 8.1 (2.6) PA Bouts (average number per day) 80 7.1 (4.3) 91 4.9 (3.6) PA measurements in autumn 8 10.0% 22 24.2% PA measurements in spring 37 46.3% 36 39.6% PA measurements in summer 35 43.8% 33 36.3% BMI (z-scores) † 80 -0.14 (0.83) 91 -0.06 (1.00) Impulsivity mean (1.00 – 5.00) 80 2.6 (0.5) 91 2.5 (0.5) Impulsivity (≤ 2.5385) 41 51.3% 50 54.9% † compared with the Fourth Dutch growth study (Fredriks et al., 2000). Bold numbers represent a statistical significant gender difference at p <0.05. PA enjoyment and PA behavior Table 2 presents the crude and adjusted relationships between PA enjoyment and PA behavior. In boys, PA enjoyment was not related with any level of PA behavior. In girls, however, PA enjoyment was significantly related to higher percentages of active (2.21, 95% CI 0.39 to 4.04) and light PA (1.51, 95% CI 0.14 to 2.88). These significant associations were attenuated in the adjusted models. Thus, although the average regression coefficients were positive indicating more/higher percentages of PA, no statistical significant associations were found. Moderators of the PA enjoyment – PA behavior relationship Age and BMI z-score showed no statistically significant interaction with PA enjoyment (data not shown, p > 0.10). In contrast, we found impulsivity to interact significantly with PA enjoyment in the relationship with active, MVPA and PA bouts in both boy and girls. As the beta-coefficient of these interactions differed in direction between boys and girls, we further explored this by computing a three-way interaction term in the linear regression model (i.e. PA enjoyment * gender * impulsivity) for the total sample (including boys and girls). The interaction model consisted of the three independent variables (PA enjoyment,