Training schedules, poor nutrition, lack of sleep, stress and consequently impacted immune systems were all factors that meant athletes were more susceptible to URTIs. Speaking with NutraIngredients, senior lecturer in exercise physiology at the University of Aberdeen Dr Stuart Gray said previous research had suggested marathon runners were up to twice as likely to contract an URTI before and after the event – an association that had even been correlated to the number of miles run per week.
The term URTI covers illnesses caused by infection of the upper respiratory tract – the nose, sinuses, pharynx or larynx – and can include things like tonsillitis, pharyngitis, laryngitis, sinusitis, otitis media (inflammation of the middle ear) as well as the common cold.
Gray - who has just published his own research on the subject in the journal International Journal of Sports Medicine - told us such infections were a source of concern for serious athletes.
“From an elite athlete point of view it is something they do worry about a lot. They’re quite paranoid about this and they are very hygiene conscious, they always shower with flip-flops on and alcohol swab their hands before touching the toilet seats and that kind of thing because they are very paranoid about coming down with a cough and a cold.”
If an individual was training for a marathon, for example, this could interfere with training and have an impact on the final time, whereby seconds could mean the difference between winning and losing.
Gray said a personalised nutrition strategy was one factor that could help to counter this.
Why are athletes more vulnerable?
Gray said the ‘open window’ theory of why athletes were more prone to this kind of illness explained that up to a few days after heavy exercise the immune system was suppressed, meaning it was less effective in searching out pathogens in the body giving the infection a greater chance to take hold.
Discussing the various risk factors, he said: “People, particularly female athletes, often are not consuming enough of the right nutrients. So that can put people at risk.”
Eating your way to a solution
In Gray’s recently published research he looked at the impact of supplementation of 550 mg of omega-3 DHA, 550 mg EPA, 10 micrograms (µg) vitamin D3 and 8 g whey protein for a period of 16 weeks compared to a placebo on a total of 42 young recreational athletes. The product used in the experiment was a sports nutrition drink made by Norwegian firm Smartfish.
The results showed that the drink did not modify the incidence, severity or duration of URTIs, although the total number of symptom days established through a survey was reduced.
Gray said the study design of multiple nutrients vs. placebo meant these results were difficult to pin down to one ingredient. Yet he said he had not been disappointed by the findings.
“You always have a hypothesis and if what you do doesn’t show that it’s just the way it is. If anything I find it more interesting if it doesn’t go the way you’d think it would because that makes you think: ‘Well I wonder why.’”
In general, Gray said athletes should be looking into personalised nutrition solutions to counter this higher risk of URTI.
“I think it needs to be more individual, so if you tested somebody and you saw that they had low evidence of omega-3 then that would probably be useful. If they were vitamin D deficient that would be useful. You need to personalise it I think."
His personal theory was that a diet of high carbohydrates in order to fuel the immune system, high protein and all the RDAs of vitamins and omega-3 was the way to go, as well as ensuring that the individual was not already deficient in things like vitamin D.
He said one limitation of his latest study was that participants were not tested to determine whether they were vitamin D deficient.
There is one approved health claim for vitamin D in the EU, stating that it “contributes to the normal function of the immune system”.
Source: International Journal of Sports Medicine
Published online ahead of print, DOI: 10.1055/s-0034-1394464
“The Effect of Fish Oil, Vitamin D and Protein on URTI Incidence in Young Active People”
Authors: M.D. Boit, B.M. Gabriel, P. Gray, S.R. Gray