Br J Sports Med doi:10.1136/bjsports-2012-091395
  • Original article

Elite athletes travelling to international destinations >5 time zone differences from their home country have a 2–3-fold increased risk of illness

Press Release
  1. Sandra Webb13
  1. lDepartment of Human Biology, Faculty of Health Sciences, UCT/MRC Research Unit for Exercise Science and Sports Medicine, University of Cape Town, Newlands, South Africa
  2. 2International Olympic Committee Research Centre, Cape Town, South Africa
  3. 3Biostatistics Unit, Medical Research Council, Parow, South Africa
  4. 4Sports Medicine Department, Olympic Park Sports Medicine Centre, Melbourne, Australia
  5. 5Medical and Scientific Department, South African Rugby Union, Cape Town, South Africa
  6. 6Discipline of Sports Science, Faculty of Health Sciences, University of Kwazulu-Natal, Durban, South Africa
  7. 7Sports Medicine Department, Australian Institute of Sport, Canberra, Australia
  8. 8Sports Medicine Department, Golden Lions Rugby Union, Johannesburg, South Africa
  9. 9Section Sports Medicine, University of Pretoria, Pretoria, South Africa
  10. 10Sports Medicine Department, Blues Super Rugby Franchise, Auckland, New Zealand
  11. 11Sports Medicine Department, Cheetahs Rugby Union, Bloemfontein, South Arica
  12. 12Sports Medicine Department, Blue Bulls Rugby Union, Pretoria, South Africa
  13. 13Highlanders, Dunedin, New Zealand
  1. Correspondence to
    Professor Martin Schwellnus, Department of Human Biology, Faculty of Health Sciences, UCT/MRC Research Unit for Exercise Science and Sports Medicine, 3rd Floor Sports Science Institute of South Africa, Boundary Road, Newlands, Cape Town 7700, South Africa; martin.schwellnus{at}, mschwell{at}
  • Accepted 28 June 2012
  • Published Online First 8 August 2012


Background Illness accounts for a significant proportion of consultations with a team physician travelling with elite athletes.

Objective To determine if international travel increases the incidence of illness in rugby union players participating in a 16-week tournament.

Setting 2010 Super 14 Rugby Union tournament.

Participants 259 elite rugby players from eight teams were followed daily over the 16-week competition period (22 676 player-days).

Assessment Team physicians completed a logbook detailing the daily squad size and illness in any player (system affected, final diagnosis, type and onset of symptoms, training/match days lost and suspected cause) with 100% compliance. Time periods during the tournament were divided as follows: located and playing in the home country before travelling (baseline), located and playing abroad in countries >5 h time zone difference (travel) and located back in the home country following international travel (return).

Main outcome measurement Incidence of illness (illness per 1000 player-days) during baseline, travel and return.

Results The overall incidence of illness in the cohort was 20.7 (95% CI 18.5 to 23.1). For all teams, the incidence of illness according to location and travelling was significantly higher in the time period following international travel (32.6; 95% CI 19.6 to 53.5) compared with the baseline (15.4; 95% CI 8.7 to 27.0) or after returning to their home country (10.6; 95% CI 6.1 to 18.2).

Conclusions There is a higher incidence of illness in athletes following international travel to a foreign country that is >5 h time difference and this returns to baseline on return to the home country.


  • Funding IOC Research Center: 2009-09-07, partial support.

  • Competing interest None.

  • Patient consent Obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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