This study investigated the impact of stress induced by repeated transmeridian travel, with particular emphasis on transmeridian time-zone crossings that compress daylight hours and disrupt circadian rhythms, on the health physiology of female volleyball athletes. Research compared pre-/post-season changes in forty-three travel-team (age 20.3±1.38) and twenty-six non-traveling (age 19.52±0.97) players from the University of Hawai'i at Hilo (UHH). Pre-season data were collected before the first travel game, with postseason data collected 15 weeks later. Data were collected using an OMRON M4-1 IntelliSense monitor, SECA 200 tape measure, GE Prodigy Lunar DXA, and salivary ELISA assays. Analyses of data were conducted using SPSS to run repeated-measures ANOVA. Significant travel-group pre- to post-season mean changes were observed in resting heart rate (57.36±7.91 vs. 63.95±8.12 bpm, respectively; p < 0.001), systolic blood pressure (110.27±6.76 vs. 114.50±6.70 mmHg, p < 0.05), diastolic blood pressure (65.28±6.03 vs. 70.08±7.03 mmHg, p < 0.001), hip circumference (96.49±7.83 vs. 93.97±8.04 cm, p < 0.01), waist circumference (76.61±7.59 vs. 78.67±7.52 cm, p < 0.01), trunk body fat deposition (27.82±6.67 vs. 30.72±6.94 %, p < 0.001), salivary cortisol (13.24±5.52 vs. 25.79±14.02 nmol/L, p < 0.01), and leg bone mineral density (1.427±0.11 vs. 1.459±0.11 g/cm2, p < 0.01). Other variables investigated in this study were not significantly different. Findings suggest that the extended intermittent stress associated with circadian rhythm disruptions throughout the volleyball season may meaningfully influence physiological health markers.
