Table 1 The characteristics of the subjects
From: Association between physical activity and academic performance in Korean adolescent students
Variables | Boys (n = 39,612) | Girls (n = 35,454) | Total (n = 75,066) | |
|---|---|---|---|---|
Age (years) | 15.00 ± 1.73 | 15.12 ± 1.77 | 15.06 ± 1.75 | |
Height (cm) | 169.58 ± 8.19 | 160.08 ± 5.39 | 165.09 ± 8.46 | |
Weight (kg) | 60.14 ± 11.72 | 51.47 ± 7.67 | 56.04 ± 10.91 | |
Body mass index (kg/m2) | 20.80 ± 3.21 | 20.05 ± 2.58 | 20.45 ± 2.95 | |
Family income status | Very rich | 2,923 (7.4) | 1,434 (4.0) | 4,357 (5.8) |
Rich | 8,985 (22.7) | 6,908 (19.6) | 15,893 (21.2) | |
Average | 17,743 (44.7) | 17,706 (49.9) | 35,449 (47.2) | |
Poor | 7,150 (18.1) | 7,090 (20.0) | 14,240 (19.0) | |
Very poor | 2,811 (7.1) | 2,316 (6.5) | 5,127 (6.8) | |
Father’s education level | Unknown* | 7,297 (18.4) | 5,321 (15.0) | 12,618 (16.8) |
Middle school or lower | 2,707 (6.8) | 2,483 (7.0) | 5,190 (6.9) | |
High school | 14,294 (36.1) | 13,915 (39.2) | 28,209 (37.6) | |
College or higher | 15,314 (38.7) | 13,735 (38.8) | 29,049 (38.7) | |
Mother’s education level | Unknown* | 8,069 (20.4) | 5,059 (14.3) | 13,128 (17.5) |
Middle school or lower | 2,447 (6.2) | 2,490 (7.0) | 4,937 (6.6) | |
High school | 17,745 (44.7) | 18,212 (51.4) | 35,957 (47.9) | |
College or higher | 11,351 (28.7) | 9,693 (27.3) | 21,044 (28.0) | |
Academic performance | Very good | 04,958 (12.5) | 03,454 (09.7) | 08412 (11.2) |
Good | 09,172 (23.2) | 08,411 (23.7) | 17583 (23.4) | |
Average | 10,544 (26.6) | 09,675 (27.3) | 20219 (26.9) | |
Bad | 09,661 (24.4) | 09,477 (26.7) | 19138 (25.5) | |
Very bad | 05,277 (13.3) | 04,437 (12.5) | 09714 (12.9) | |
Grade | 7th | 6,933 (17.5) | 5,781 (16.3) | 12,714 (16.9) |
8th | 6,965 (17.6) | 5,903 (16.6) | 12,868 (17.1) | |
9th | 7,035 (17.7) | 5,792 (16.3) | 12,827 (17.1) | |
10th | 6,890 (17.4) | 5,587 (15.8) | 12,477 (16.6) | |
11th | 6,104 (15.4) | 6,323 (17.9) | 12,427 (16.6) | |
12th | 5,685 (14.4) | 6,068 (17.1) | 11,753 (15.7) | |