Table 2.
Measures of hydration, psychomotor vigilance, and balance performance, mean (SD).
| Characteristic | August pear harvest (n = 34)
|
September apple harvest (n = 12)
|
All (N = 46)
|
||||
|---|---|---|---|---|---|---|---|
| Pre-shift | Post-shift | Pre-shift | Post-shift | Pre-shift | Post-shift | t-test, p value | |
| Urine specific gravitya | 1.025 (0.008) | 1.024 (0.007) | 1.028 (0.004) | 1.025 (0.004) | 1.025 (0.007) | 1.025 (0.007) | t(44) = 0.91, p = 0.400 |
| Psychomotor vigilance task (PVT) reaction time (ms)a | 644 (288) | 553 (285) | 911 (508) | 772 (428) | 715 (373) | 611 (338) | t(43) = 3.4, p = 0.002 |
| Psychomotor vigilance task (PVT) number of lapses Balance performance, total path length (cm) | 21 (15) | 15 (14) | 27 (13) | 28 (15) | 23 (15) | 18 (15) | t(43) = 2.3, p = 0.029 |
| Eyes open | 45.7 (13.8) | 37.1 (10.6) | 45.3 (10.4) | 39.4 (9.1) | 45.6 (12.9) | 37.7 (10.2) | t(45) = 3.8, p < 0.001 |
| Eyes closed | 63.8 (19.3) | 55.8 (16.4) | 62.0 (20.6) | 53.1 (12.4) | 63.3 (19.4) | 55.1 (15.4) | t(45) = 3.1, p = 0.004 |
a
One pear harvest worker pre-work-shift and one pear harvest worker post-work-shift values missing.