Table 1: Baseline characteristics across grade cohorts, total study sample, and baseline physical activity.

Baseline student characteristicsGrade 9
( )
Grade 10
( )
Total
( )
Baseline physical activity
( )
% % %meanSD

Age (years), mean ± SD14.8±0.70515.9±0.41915.2±0.818N.A.
Gender
 Male142(48.0)62(41.1)204(45.6)64.6±23.3
 Female151(51.0)88(58.3)239(53.5)53.0±23.0

BMI category
 Overweight or obese40(13.5)21(13.9)61(13.6)58.2±23.8
 Healthy weight143(48.3)85(56.3)228(51.0)58.0±23.5
 Missing109(36.8)45(29.8)154(34.5)58.6±24.9

Baseline physical activity level
 Low 103(34.8)46(30.5)149(33.3)32.8±8.4
 Moderate89(30.1)60(39.7)149(33.3)56.4±6.4
 High104(35.1)45(29.8)149(33.3)85.8±14.2

Baseline school neighbourhood characteristics

School location
 Rural73(24.7)60(39.7)133(29.8)48.8±19.6
 Urban223(75.3)91(60.3)314(70.2)62.4±24.5

Socioeconomic status
 Low204(68.9)104(68.9)308(68.9)55.3±22.9
 High92(31.1)47(31.1)139(31.1)65.0±24.9

Proportions may not add up to 100% due to missing values.
N.A.: not applicable.