Effects of long-haul transmeridian travel on player preparedness: Case study of a national team at the 2014 FIFA World Cup.

OBJECTIVES Describe the effects of eastward long-haul transmeridian air travel on subjective jet-lag, sleep and wellness in professional football (soccer) players prior to the 2014 FIFA World Cup in Brazil. DESIGN Single cohort involving twenty-two male professional football players representing a national football team. METHODS Data was collected from players prior to and following international travel from Sydney, Australia to Vitoria, Brazil. In total there were three flights, 19-h and 14,695km of travel east across 11 time-zones. Training load and wellness measures were obtained in the week prior to and following travel, whilst sleep and jet-lag measures were collected on the day prior to travel (Pre), the day of arrival and for five days following travel (Post 1-5). RESULTS Compared to Pre, perceived jet-lag was significantly increased on Post 1 to 4, with significantly greater levels on Post 1 compared to Post 5 (p<0.05). Self-reported sleep duration during travel was 5.9 (4.8-7.0) h, which was significantly lower than all other nights (p˂0.01), except for the night of arrival, where time in bed and sleep duration were significantly reduced compared to Post 1-4 (p˂0.01). Lastly, compared to the week prior to travel, mean wellness was significantly reduced during the week following travel (p˂0.01). CONCLUSIONS Self-reported sleep disruption during and following eastward long-haul transmeridian air travel, together with exacerbated jet-lag symptoms may result in reduced player wellness. Consequently, player preparedness for subsequent training and competition may be impeded, though physical performance data is lacking.