Table 2. Accelerometry variables at each age in boys and girls.
| Age (years) |
|||||||
|---|---|---|---|---|---|---|---|
| 3 | 4 | 5 | 5.5 | 6.5 | 7 | ||
| Girls | Number of valid days | 5.6a (0.7) | 5.9b (0.8) | 6.8c (0.5) | 6.9c (0.4) | 6.8c (0.5) | 6.5c (0.9) |
| Hours worn/day 1 | 12.0ab (0.8) | 12.1ab (0.7) | 12.1a (0.7) | 12.0ab (0.7) | 12.2ab (0.7) | 12.2b (0.7) | |
| Counts per minute | 773a (264) | 522b (220) | 506b (212) | 382c (128) | 483b (168) | 499b (205) | |
| Ratio of 2LMV:S (%) | 3.7a (3.1, 5.0) | 2.3b (2.1, 2.6) | 2.2b (2.0, 2.4) | 1.7c (1.5, 1.9) | 1.9b (1.6, 2.1) | 1.8b (1.6, 2.0) | |
| Boys | Number of valid days | 5.7a (0.7) | 6.2b (0.8) | 6.9c (0.4) | 6.9c (0.3) | 6.7d (0.6) | 6.5d (0.8) |
| Hours worn/day 1 | 11.9a (0.9) | 12.0ab (0.8) | 12.2b (0.8) | 12.2b (0.7) | 12.4c (0.7) | 12.5b (0.8) | |
| Counts per minute | 813 (249)a | 532b (200) | 542b (244) | 444c (165) | 544b (245) | 554b (230) | |
| Ratio of 2LMV:S (%) | 4.0a (3.1, 4.9) | 2.4b (2.2, 2.8) | 2.3b (2.0, 2.5) | 1.8c (1.6, 2.1) | 1.9d (1.7, 2.2) | 1.8d (1.6, 2.1) | |
Data are presented as mean (SD) except for the ratio which is presented as median (25th, 75th percentiles).
1
Once sleep and non-wear time have been removed.
2
Intensity of activity categories calculated from Evenson et al [20].
Values with different superscripts within the same row indicate significant differences (P < 0.05) by age.