Updated: Jul 8, 2019
Over the years, ever since my final year of university, I've been weirdly interested in methods to overcome illness via nutrition. It's known as immunology when you do your module on it at uni. I'm not sure why I found it so fascinating, maybe because it wasn't very glamorous (and I wanted to make it glamorous...) but I liked the concept that you could maximise and promote recovery of an athlete and therefore wider population via a particular nutrition protocol and naturally minimise the incidence of illness in the first place.
Exercise and Immune function, we hear all sorts of things about this.
Exercise makes us stronger...don't train too hard or you'll make yourself sick...if you get sick have a hot toddy.
Well I'm not sick but I may just have that whisky anyway! Down to business, this article isn't to go into great detail about the two main theories around how we become sick as a slight link to exercise but if you want to find out more, those two theories are the J-Curve Theory and the Open-Door Theory. To summarise though, if you perform moderate exercise, you do indeed make yourself less susceptible to Upper respiratory tract infections (URTI's or a cold and cough to you and I). This doesn't mean you won't get one, sometimes we just get ill.
Fondell et al 2011, found that 1hr of activity per day has an 18% reduced chance of URTI.Those with high stress and performed a high intensity activity reduced URTI even further. Oddly, the researchers observed a suppressed immune response when people had lower psychological stress in their daily lives.
However, very intense training or very long durations of training do make you vulnerable for a short period of time after exercise and it is this period of time you want to minimise contact with those who are sick, highly populated areas or air conditioning...yes all the things that happen within hours of being a competing international athlete.
Finally, IF you have relatively low levels of daily stress, 30 minutes of high intensity training is better than 2 hours of low intensity training to reduce the likelihood of a URTI.
Zinc There are very few things which have been shown to have a real effect on the common cold but zinc acetate lozenges (mine were a source of constant laughter in my old office because they are about the size of a golf ball…) are suggested to be very effective at reducing the duration of a cold. Hemila, 2011 conducted a meta analysis and concluded that figure might even be a 42% reduction in colds [ https://www.ncbi.nlm.nih.gov/pubmed/21769305 ] and from anecdotal experience I stand by that.
Zinc acetate appeared to be the most effective (in the review I posted above) however other zinc lozenges were still effective, but only found about a 20% reduction in the duration of colds! One thing to note is that doses below 75mg don't seem to be effective at all! With that in mind, all zinc lozenges of a sufficient dosage should be somewhat effective however zinc acetate appears to have the strongest effect!
I would always advise that you check with a doctor before taking supplements and you can check drug interactions using an online tool such as this one: https://www.webmd.com/interaction-checker/default.htm
Naturally, there is plenty of research surrounding Vitamin C supplementation, interestingly it's suggested that vitamin C is only really worth supplementing when you are ill but it also has an effect, albeit a lesser effect, to reducing the duration of a cold. Supplementation needs to be spread throughout the day to ensure you don't wee it out and effective dosages vary between 500mg to 4000mg. Vitamin D
This vitamin is superhuman, it's amazing and we're still learning about it but it appears to be in the functioning of so so many processes within the human body. Nearly everyone in the northern hemisphere is also deficient in it. Optimise your vitamin D levels and to do this try and get a vitamin d blood check done to find out how deficient to sufficient. One word of warning, falling in the bracket of 'sufficient' or 'adequate' shouldn't be confused with being optimal. Think of 'adequate' being like your bank account balance being zero. You're not in debt yet but I am pretty sure you'd prefer to have a bit of money in there (that might be my best analogy to date).
If you're really deficient then you'll need a large corrective dose under the supervision of a health professional followed by a regular dose of 1000 (summer) -2000(winter) iu's per day. In addition to this, the darker your skin pigmentation the greater amount you need so this may look like 2000 - 3000iu per day. BE CAREFUL, Vitamin D is toxic so I do not advise you to create your own dosage without consulting your GP or MD.
Finally, if you're told that you don't need to take Vitamin D in the UK during the summer, and you live here in the UK...find another professional who will hopefully give you correct advice.
The evidence supporting probiotic supplements is in it's infancy and there is no clinical significance to it's consumption yet! However, it is recommended particularly when you are taking anti-biotics and from two personal, anecdotal accounts. On a long work trip, I was consuming probiotics for 6 weeks prior to a trip abroad and was the only member of the team, working and staying in close proximity with one another not to get it. This persisted on our return to the UK. I stopped my consumption after 2 weeks and became ill and the same occurred just 2 months ago so I do tend to sway towards that...or the fact that I drank beer during the trip whilst they had the water...let's say it was the supplementation.
We are aware that as calories are reduced, micronutrient intake (vitamins and minerals) can also very often reduce making one more vulnerable to illness. Therefore, ensure calories in matches calories expended during training. This would suggest that if someone is ill perhaps keep them at maintenance calories if their cold/cough becomes extended, doesn’t improve or the URTI (Upper respiratory tract infection) starts to move down the throat towards the chest.
Protein is directly related to immune functioning, consume 1.2-2g per kg of bodyweight per day as part of your daily calories to optimise your health alongside your vegetables. Dairy sources of protein will provide you with glutamine which shows some support for immune health, although that's very limited. Whilst red meat will provide you with B Vitamins. If you're vegetarian, try and choose soya sources of protein and hit the higher end of those recommendations but account for this in your calories to ensure this doesn't lead to weight gain.
One of the most applied messages relating upper respiratory tract infections given to athletes is to refrain from aerobic exercise if the cold goes beyond the throat, to ensure it does not turn into a chest infection.
Reduce your training time, frequency and you may need to moderate your training intensity.
Zinc Lozenges are great and Zinc Acetate is the best form but others work. With Vitamin C too!
Optimise Vitamin D levels
Eat a healthy diet full of protein and vegetables
Maintain your calorie intake
Probiotics may be useful
I hope this has been useful folks, make sure you let me know your thoughts by dropping me a message on Instagram, Facebook or via e-mail! Train Hard,
Effect of exercise on illness:
Zinc & URTI's:
Hemilia (2017) :https://www.ncbi.nlm.nih.gov/pubmed/28515951