Frequency (percentage) of participants who reported averaging nightly sleep durations within each category
| Sleep duration (hours) | All soldiers (%) | Reported injury (%) | No reported injury (%) |
| <4 | 12 (3.9) | 7 (6.0) | 5 (2.6) |
| ≥4 to <5 | 29 (9.4) | 16 (13.8) | 13 (6.8) |
| ≥5 to <6 | 72 (23.4) | 29 (25.0) | 43 (22.4) |
| ≥6 to <7 | 120 (39.0) | 41 (35.3) | 79 (41.1) |
| ≥7 to <8 | 49 (15.9) | 17 (14.7) | 32 (16.7) |
| ≥8 to 9 | 26 (8.4) | 6 (5.2) | 20 (10.4) |