New research has revealed that athletes who travel more than five time zones for competitions are more likely to get sick compared to when they play at home.
Athletes are two to three times more likely to get ill following extensive international travel, the study suggests.
Researchers at the Institute of South Africa in Cape Town examined 259 players competing in the 2010 Super 14 rugby tournament.
During the 16 week competition, 14 teams from Australia, New Zealand and South Africa travel to venues in all three countries which are in time zones between two to 11 hours different from their own.
The authors examined data taken by the team doctors on a daily basis.
The research, published in the British Journal of Sports Medicine, found that 187 of the athletes fell ill during the contest, with illnesses more likely to occur on foreign soil.
Researchers noted that most of the illnesses were infections. Respiratory problems, such as coughs, colds and chest infections, accounted for almost a third of all illnesses and gut problems including stomach bugs accounting for 27.5%.
The authors suggest that various factors could be linked to the increase in illness, including changes in pollution, temperature, allergens, humidity, altitude, as well as different food, germs, and culture.
In the run up to the London 2012 Games, athletes from both Australia and Canada fell ill following travel to England.
Two Canadian badminton players and three Australian athletes acquired a stomach virus during pre-Games training in Derby.
However, health experts said a small number of illnesses in athletes are to be expected.
The Health Protection Agency (HPA) has a team working in the polyclinic in the Athletes Village to detect any possible infectious diseases.
The HPA's director for London during the Games, Dr Deborah Turbitt, said every day "a few" athletes or team officials had attended the on-site clinic with rashes, vomiting or diarrhoea.
"Every day there is a few people turning up with those symptoms," she said.
"We knew we would see some bugs because there are bugs in the population all the time.
"We have seen a few people with the general respiratory and gastrointestinal illnesses you'd expect in any population really.
"We said we thought there would be a bit of tummy upsets and there have been. We knew there would be a few people with coughs and colds and sneezes and there have been."
The HPA has implemented a raft of measures to ensure that any potential diseases are spotted and addressed as quickly as possible in both athletes and the general population.
Dr Turbitt added: "We've had systems in place to detect that sort of thing because we set up surveillance systems to detect outbreaks and incidents of disease.
"We haven't detected any outbreaks in either athletes or work force or team officials but we have seen very low numbers.
"Across London we've not detected anything other than the usual background levels of all of the diseases that we normally see. There hasn't been any rise or fall in anything, it has been very steady."Reuse content