Table 1.
Baseline characteristics of the study participants
| Characteristics | Overall (n = 92,139) | Morning (n = 15,865) | Midday-afternoon (n = 41,125) | Evening (n = 8307) | Mixed (n = 26,842) |
|---|---|---|---|---|---|
| Age at accelerometry (years) | 62.38 ± 7.84 | 63.54 ± 7.81 | 63.58 ± 7.43 | 59.31 ± 7.96 | 60.81 ± 7.90 |
| Sex (female/male) | 52,045/40,094 | 9140/6725 | 22,941/18,184 | 4413/3894 | 15,551/11,291 |
| White ethnicity | 89,323 (96.94) | 15,343 (96.71) | 40,183 (97.71) | 7930 (95.46) | 25,867 (96.37) |
| Townsend deprivation index, median [IQR] | −2.45 [3.63] | −2.53 [3.51] | −2.53 [3.49] | −2.35 [3.80] | −1.58 [2.88] |
| Recruitment regions | |||||
| England | 82,716 (89.77) | 14,396 (90.74) | 36,883 (89.69) | 7438 (89.54) | 23,999 (89.41) |
| Wales | 3449 (3.74) | 591 (3.73) | 1538 (3.74) | 340 (4.09) | 980 (3.65) |
| Scotland | 5974 (6.48) | 878 (5.53) | 2704 (6.58) | 529 (6.37) | 1863 (6.94) |
| Education level | |||||
| Degree or above | 40,348 (43.79) | 6282 (39.62) | 17,732 (43.12) | 3953 (47.59) | 12,377 (46.11) |
| Any other qualification | 44,118 (47.88) | 7943 (50.07) | 19,661 (47.81) | 3935 (47.37) | 12,579 (46.86) |
| No qualification | 7673 (8.33) | 1636 (10.31) | 3732 (9.07) | 419 (5.04) | 1886 (7.03) |
| Season of accelerometer wear | |||||
| Spring | 20,792 (22.57) | 3476 (21.91) | 9217 (22.41) | 1888 (22.73) | 6211 (23.14) |
| Summer | 24,068 (26.12) | 4017 (25.32) | 9966 (24.23) | 2640 (31.78) | 7445 (27.74) |
| Autumn | 27,583 (29.94) | 4810 (30.32) | 12,700 (30.88) | 2337 (28.13) | 7736 (28.82) |
| Winter | 19,696 (21.38) | 3562 (22.45) | 9242(22.47) | 1442 (17.36) | 5450 (20.30) |
| Smoking status | |||||
| Never | 52,952 (57.47) | 8810 (55.53) | 23,330 (56.73) | 4945 (59.53) | 15,867 (59.11) |
| Previous | 33,382 (36.23) | 6130 (38.64) | 15,195 (36.95) | 2761 (33.24) | 9296 (34.63) |
| Current | 5805 (6.30) | 925 (5.83) | 2600 (6.32) | 601 (7.23) | 1679 (6.26) |
| Alcohol consumption | |||||
| Not current | 5500 (5.97) | 1093 (6.89) | 2377 (5.78) | 456 (5.49) | 1574 (5.86) |
| Two or less times a week | 42,645 (46.28) | 7429 (46.83) | 18,547 (45.10) | 3969 (47.78) | 12,700 (47.31) |
| Three or more times a week | 43,994 (47.75) | 7343 (46.28) | 20,201 (49.12) | 3882 (46.73) | 12,568 (46.82) |
| Healthy diet score | 2.69 ± 1.17 | 2.72 ± 1.17 | 2.70 ± 1.17 | 2.61 ± 1.17 | 2.67 ± 1.16 |
| Sleep duration | |||||
| <7 h/day | 31,750 (34.46) | 5526 (34.83) | 12,651 (30.76) | 3393 (40.85) | 10,180 (37.93) |
| 7–8 h/day | 42,206 (45.81) | 7215 (45.48) | 19,038 (46.29) | 3675 (44.24) | 12,778 (45.74) |
| >8 h/day | 18,183 (19.73) | 3124 (19.69) | 9436 (22.94) | 1239 (14.92) | 4384 (16.33) |
| Sleep midpoint (hh:mm) | |||||
| <02:30 | 23,823 (25.86) | 5805 (36.59) | 9545 (23.21) | 1769 (21.30) | 6704 (24.98) |
| 02:30-03:30 | 43,025 (46.70) | 7286 (45.92) | 18,934 (46.04) | 3635 (43.76) | 13,170 (49.06) |
| >03:30 | 25,291 (27.45) | 2774 (17.49) | 12,646 (30.75) | 2903 (34.95) | 6968 (25.96) |
| Health status | |||||
| Obesity | 17,930 (19.46) | 3421 (21.56) | 7829 (19.04) | 1777 (21.39) | 4903 (18.27) |
| Diabetes history | 4265 (4.63) | 872 (5.50) | 1866 (4.54) | 408 (4.91) | 1119 (4.17) |
| Longstanding illness | 27,086 (29.40) | 4917 (30.99) | 12,472 (30.33) | 2312 (27.83) | 7385 (27.51) |
| Depression history | 8171 (8.87) | 1368 (8.62) | 3630 (8.83) | 771 (9.28) | 2402 (8.95) |
| Cardiovascular diseases | 22,661 (24.59) | 4338 (27.34) | 10,702 (26.02) | 1781 (21.44) | 5840 (21.76) |
| Cancer history | 13,428 (14.57) | 2500 (15.76) | 6423 (15.62) | 990 (11.92) | 3515 (13.10) |
| Total MVPA volume (min/week), median [IQR] | 113.83 [158.67] | 108.22 [170.00] | 112.83 [153.17] | 104 [148.92] | 120.83 [163.50] |
IQR interquartile range, MVPA moderate to vigorous physical activity.
Data were mean ± standard deviation or n (%) unless noted otherwise. To assign categories of the timing of MVPA, we divided the clock hours (05:00 to 24:00) into three time windows: morning (05:00–11:00), midday-afternoon (11:00–17:00), and evening (17:00–24:00). These time windows were identified from the exploratory analyses on the timing effects of PA on mortality outcomes (Supplementary Fig. 5). If ≥50% of MVPA occurred during the same time window, participants were assigned to the corresponding timing group. The 50% method we used to define the timing of MVPA is similar to what has been previously used [Qian et al. Diabetes Care. 2021].