## 3 Results  
The characteristics of the study participants are shown in Table 1. The mean age was 8.7 years old (SD = 1.8). The proportion of participants with excess weight was 42.3%. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Variables** & **M (SD)/n (\%)** & **CI 95\%** \\ \hline Age (years) & 8.7 (1.8) & 8.5–8.9 \\ \hline Sex, (\%, boys) & 193 (55.1) & 49.9–60.4 \\ \hline Type of schooling (\%, public) & 234 (66.9) & 61.9–71.8 \\ \hline Area of residence (\%, urban) & 271 (77.4) & 73.0–81.8 \\ \hline Immigrant status (\%, native) & 184 (81.1) & 47.3–57.8 \\ \hline Weekly sport activities & & \\ \hline None (\%) & 31 (8.9) & 5.9–11.8 \\ \hline
1 h (\%) & 53 (15.1) & 11.4–18.9 \\ \hline
2 h (\%) & 97 (27.7) & 23.0–32.4 \\ \hline
3 h (\%) & 52 (14.9) & 11.1–18.6 \\ \hline
4 h (\%) & 32 (9.1) & 6.1–12.2 \\ \hline
5 or more h (\%) & 85 (24.3) & 19.8–28.8 \\ \hline Daily screen time & & \\ \hline None (\%) & 26 (7.4) & 4.7–10.2 \\ \hline
1 h (\%) & 143 (40.9) & 35.7–46.0 \\ \hline
2 h (\%) & 126 (36.0) & 31.0–41.0 \\ \hline
3 h (\%) & 38 (10.9) & 7.6–14.1 \\ \hline
4 h (\%) & 11 (3.1) & 1.3–5.0 \\ \hline
5 or more h & 6 (1.7) & 0.4–3.1 \\ \hline Anthropometric data & & \\ \hline Weight (kg) & 35.9 (10.9) & 34.8–37.0 \\ \hline Height (cm) & 135.9 (11.8) & 134.7–137.1 \\ \hline BMI (z-score) a  & 1.14 (1.24) & 1.01–1.27 \\ \hline Excess weight a (\%) & 148 (42.3) & 37.1–47.5 \\ \hline Physical fitness & & \\ \hline
20 m Shuttle Run Test (stages) & 2.7 (1.5) & 2.5–2.9 \\ \hline Cardiorespiratory fitness (mL/kg/min) & 45.0 (4.2) & 44.8–45.2 \\ \hline Handgrip strength (kg) & 13.1 (4.0) & 12.7–13.5 \\ \hline Handgrip strength/body weight & 0.37 (0.08) & 0.36–0.38 \\ \hline Standing broad jump (cm) & 113.8 (25.0) & 111.2–116.4 \\ \hline \multicolumn{4}{c}{4 \(\times\) 10 Shuttle Run Test (s)} & 13.74 (1.43) & 13.59–13.89 \\ \hline \end{tabular} Data expressed as numbers (percentages) or mean (standard deviation), and 95% confident intervals. a Excess weight (overweight and obesity) determined by the World Health Organization criteria [25]. BMI, body mass index.  
\end{table} 
Table 1: Descriptive data of the Spanish schoolchildren analyzed (N = 350). Figure 1 shows the proportion of schoolchildren performing in different intensities of PA during PE classes and school recesses. Overall, 49.1% of the schoolchildren reported to be very active \"always\". Furthermore, the 26.6% of the analyzed sample declared \"play intensely\" during the school recesses. Moreover, the proportion of schoolchildren with high-intensity during both PE classes and school recesses was 38.9%. Figure 1: Proportion of schoolchildren reporting different intensities of physical activity according to Physical Education classes and school recesses, individually and in combination. PA, physical activity; PE, physical education. Figure 2 shows the mean differences between zBMI and zGFS according to PA intensity during PE classes and school recesses. Thus, zBMI was lower in those who reported higher intensity of PA in PE lesson, school recesses and both settings (\(p<0.05\) for all). Conversely, zGFS was higher in schoolchildren who engaged in higher intensity of PA in PE classes, school recesses, and both settings (\(p<0.05\) for all). Figure 3 indicates the odds ratio of having excess weight or being in the high GFS tertile in relation to PA intensity during PE classes, school recesses, or both settings. A lower odd of having excess weight was found in those engaging in high intensity of PA in PE classes (OR = 0.55; CI 95%, 0.37-0.84), and in both PE lesson and school recesses (OR = 0.54; CI 95%, 0.30-0.96). Conversely, higher odds of being in the high GFS tertile were found in schoolchildren engaging in high intensity of PA in PE classes (OR = 1.96; CI 95%, 1.25-3.08), as well as in both PE lessons and school recesses (OR = 1.96; CI 95%, 1.01-3.85). Figure 2: Mean differences in body mass index (z-score) and global physical fitness (z-score) in relation to physical activity intensity during Physical Education classes and school recesses.