Table 1

Characteristics of the SPEEDY sample at waves 1–3

Baseline1-Year follow-up†4-Year follow-up≥2 Time points‡
N consented20641019480
N with ≥1 day PA data (% of consenting sample)1978 (95.8)930 (91.2)428 (89.2)990 (48.0% of baseline)
N with ≥3 days PA data (% of consenting sample)1868 (90.5)882 (86.6)386 (80.4)931 (45.1% of baseline)
Age (years)10.3 (0.3)11.2 (0.3)14.3 (0.3)10.2 (0.3)2
Percentage of female55.658.4253.5ns57.52
Weight (kg)36.5 (8.4)57.1 (12.4)36.1 (8.4)ns
Height (cm)141.0 (6.7)165.0 (7.6)141.0 (6.7)ns
BMI z-score0.3 (1.1)0.4 (1.2)0.2 (1.1)2
Overweight and obese (%)23.020.622.03
Body fat percentage23.6 (6.7)21.5 (8.1)23.3 (6.6)2
Parental age at leaving education (≤16 vs >16 years)55.157.8ns56.2257.5ns
Home location (all baseline values; %)
 Urban39.033.6138.2ns35.11
 Town/suburban28.730.926.030.2
 Rural32.335.535.834.7
Sedentary (min)455.3 (55.9)469.8 (54.8)500.7 (58.6)456.8 (53.7)ns
LPA (min)181.2 (32.7)177.1 (31.3)139.6 (33.5)181.9 (32.50)ns
MPA (min)48.7 (14.5)47.5 (13.9)42.9 (15.9)48.7 (13.9)ns
VPA (min)6.1 (6.5)6.1 (5.1)3.0 (4.2)6.1 (6.6)ns
MVPA (min)73.9 (25.2)71.7 (22.9)62.0 (24.7)73.8 (24.1)ns
  • Participant characteristics are presented for participants with ≥1 day of physical activity data (mean and SD, unless otherwise stated).

  • t Tests or χ2 tests used to test differences between 1-year and 4-year follow-up and ≥2 waves compared to baseline data where appropriate: 1p<0.001; 2p<0.05; nsp>0.05.

  • Descriptive data presented for participants with ≥1 day accelerometer data at each wave.

  • Baseline values presented for participants who had data for ≥2 waves.

  • Wave 2 was postal data collection and anthropometry was not measured.

  • †Anthropometry data was not collected at 1-year follow-up.

  • ‡Baseline data presented.

  • BMI, body mass index; LPA, light physical activity; MPA, moderate physical activity; MVPA, moderate and vigorous physical activity; PA, physical activity; SPEEDY, Sport, Physical activity and Eating behaviour: Environmental Determinants in Young people; VPA, vigorous physical activity.