Table 2. Population Characteristics and Selection.
| Study population (N = 1403) | Population with diaried leisure sport (N = 1010) | Population with diaried school sport (PE) (N = 882) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Boys | Girls | P for sex difference | Boys | Girls | P for sex-stratified difference1 | Boys | Girls | P for sex-stratified difference1 | |||
| Male (N, %) | 650 (46) | ** | 455 (45) | — | 407 (46) | — | |||||
| Age, years | 15.6 (0.5) | 15.6 (0.5) | — | 15.6 (0.5) | 15.6 (0.5) | — | — | 15.6 (0.5) | 15.6 (0.5) | — | — |
| Height, cm | 177 (7.4) | 168 (6.2) | <0.0001 | 177 (7.4) | 168 (6.2) | — | — | 177 (7.4) | 168 (6.3) | — | — |
| Weight, kg | 64.5 (12) | 59.0 (9.6) | <0.0001 | 64.0 (11) | 59.0 (9.4) | — | — | 64.4 (12) | 58.5 (9.3) | — | 0.09 |
| BMI, kg/m2 | 20.6 (3.2) | 21.0 (2.9) | 0.001 | 20.4 (2.9) | 21.0 (2.9) | 0.04 | — | 20.6 (3.1) | 20.8 (2.9) | — | 0.1 |
| Study center Munich, % | 64.9 | 57.5 | 0.005 | 66.4 | 56.4 | — | — | 62.6 | 56.6 | — | — |
| Higher-educated parent entered university, % | 71.1 | 71.1 | — | 75.8 | 73.2 | 0.0001 | 0.04 | 70.9 | 71.2 | — | — |
| BMI category,4% | ** | ** | ** | ** | ** | ** | ** | ** | ** | ** | ** |
| Underweight | 9.06 | 6.29 | ** | 9.07 | 5.26 | — | — | 9.41 | 7.43 | — | 0.1 |
| Normal weight | 79.7 | 84.9 | ** | 82.1 | 86.4 | — | — | 78.9 | 84.9 | — | — |
| Overweight | 8.59 | 4.95 | ** | 7.03 | 5.08 | — | — | 9.41 | 4.25 | — | — |
| Obese | 2.70 | 3.88 | ** | 1.81 | 3.27 | — | — | 2.29 | 3.40 | — | — |
| Any diaried leisure sport (%) | 70.0 | 73.7 | — | ** | ** | ** | ** | 74.2 | 76.4 | 0.003 | 0.03 |
| Any school physical education PE (%) | 62.6 | 63.1 | — | 66.4 | 65.4 | 0.003 | 0.03 | ** | ** | ** | ** |
| Accelerometric data, min/day; Mean (SD) | |||||||||||
| Time from getting up to going to bed (includes accelerometer non-wear, NWT) Mean (SD) | 904 (52) | 898 (49) | 0.02 | 906 (50) | 899 (49) | 904 (52) | 899 (47) | ||||
| Accelerometer wear;3, 4 Does not include NWT Mean (SD) | 887 (54 | 881 (49) 799, 962 | 0.01 | 888 (54) | 881 (49) | — | — | 887 (53) | 882 (47) | — | — |
| Sedentary3 | 583 (79) | 598 (69) | 0.0001 | 580 (74) | 594 (65) | — | 0.005 | 583 (77) | 597 (67) | — | — |
| Light3 | 260 (59) | 246 (50) | <0.0001 | 261 (57) | 250 (49) | — | 0.0002 | 260 (60) | 248 (49) | — | — |
| Moderate3, 4 | 31.3 (14) | 26.5 (15) | <0.0001 | 33.1 (14) | 26.8 (14) | <0.0001 | 0.00035 | 32.2 (14) | 26.9 (14) | 0.049 | 0.02 |
| Vigorous3, 4 | 14.2 (12) | 11.1 (11) | ** | 15.7 (12) | 11.8 (11) | <0.0001 | <0.0001 | 14.4 (12) | 11.5 (10) | — | 0.006 |
| MVPA3, 4 | 45.5 (22) | 37.6 (23) | ** | 48.8 (22) | 38.6 (20) | <0.0001 | <0.0001 | 46.5 (23) | 38.3 (22) | — | 0.007 |
| MVPA difference from average3, 4 | ** | ** | ** | 3.24 | 1.01 | ** | ** | 0.94 | 0.72 | ** | ** |
| % days with MVPA over 60 minutes3, 4 | 27.2 | 17.7 | <0.0001 | 31.2 | 19.0 | <0.0001 | <0.0001 | 28.6 | 19.1 | 0.10 | 0.004 |
| MVPA over 60 minutes every day; N, % subjects3, 4 | 6, 0.92 | 8, 1.06 | - | 4, 0.88 | 5, 0.90 | — | — | 4, 0.98 | 6, 1.26 | — | — |
Mean (SD) unless otherwise stated.
Table 2 footer: P-values calculated using t-test for centrally distributed variables (age, height, BMI, weartime, sedentary, and light); Kruskal-Wallis for categorical (BMI category); Wilcoxon’s two-tailed rank-sum for binary and skewed (all others.)—if p>0.10, ** if pairwise comparison inappropriate (see global null.) For time and activity levels spent in various activity domains (leisure sport, school PE, transportation, school) see Table 4.
1) P-value for difference from whole cohort
2) From BMI cutpoints in (Kromeyer-Hauschild, 2001).[36]
3) Freedson’s uniaxial algorithm for children from (Freedson, 2005) [34]as cited in (Trost, 2010).[34, 37]
4) Data include estimated moderate and vigorous activity during nonwear time if the subject diaried they were in school PE or leisure sport.