Last updated: 02-Mar-16
Written by Sports Dietitian Rin Cobb
Warding off those winter colds, flu (self-proclaimed manflu included) or even the dreaded norovirus may seem like a futile effort at this time of year but despite this, many of you will be taking a multitude of nutritional supplements, in belief or hope they’ll keep you lurgy free, whilst debating whether you should run that 40miler at the weekend when you’re full of cold. However there are a number of nutrients to stock up your immunity larder to help keep your immune system in tiptop condition allowing you to keep up with your hefty training schedule.
Have you ever finished a race and soon after been bed ridden with an illness of some sorts? Whilst a ‘moderate’ amount of exercise has been shown to be protective against respiratory infections and other conditions such as diabetes, heart disease and osteoporosis; there does appear to be a dose response and as you increase that mileage so does your risk of illness. In fact as ultra runners, if you’re running more than 60miles per week, you’re twice as likely to become unwell compared to those who run less than 20miles per week. There also appears to be a 90-minute window, which opens up the body’s susceptibility to illness which maybe something to consider when working out your training strategy.
It may not come as a surprise that in order to keep your immune system up and running, you need to have a good balance of nutrients from your diet. Nutritional deficiencies, restricted diets and losing weight quickly can all put an additional strain on the immune system, leading to an increased risk of illness so here’s what to stock up on.
The WBD (aka a well balanced diet)
Ensure you’re meeting your energy, carbohydrate and protein needs on a day-to-day basis. Try spreading out your intake throughout the day by including starchy carbs and protein with each meal. When it comes to training, particularly your longer runs make sure you’re having plenty of carbohydrate throughout. Carbs not only fuel your muscles but also your immune system and having depleted carb stores is associated with immunodepression. Having a good range and plenty of fruit and veg will help ensure you have an adequate antioxidant intake and prevent any deficiencies.
Most people can meet their vitamin and mineral needs through their diet but if for any reason you have a restricted intake, taking a multivitamin supplement maybe warranted. There is however no additional benefit to taking vitamin supplements if having a well balanced diet and could in fact do more harm than good. Many multivitamins far exceed the recommended daily allowance (RDA) and if taking in combination with individual supplements, you could find yourself on mega doses which may actually impair your immune system or even have toxic affects.
No doubt you’ll have been told at some stage or another that Vitamin C will stop you getting a cold however the evidence is somewhat inconsistent certainly for the general public. There have been a number of studies however looking at supplementation in marathon and ultra runners and there does appear to be some benefit with doses between 200-1000mg per day, particularly in the weeks leading up to an event. On a slight tangent, the American College of Sports Medicine does recommend doses of Vitamin C within this range if participating in prolonged, strenuous exercise due to increased requirements, which I’m sure you’ll agree encompasses ultra running.
Zinc is essential for the development of your immune system so it’s no surprise that the link between supplementation and immune function has been made. However, once again if meeting your zinc needs through your diet, supplementation is not necessary but as zinc is mainly found in meat and seafood, vegetarians can be at risk of deficiency and may warrant taking a supplement but always try to get your levels checked first. Whilst some studies have suggested a beneficial effect of zinc in treating the common cold, this is only if taken within the first 24hrs of symptoms developing. However supplementation may also impair other elements of immune function so the potential pros and cons need to be weighed up but zinc supplements certainly shouldn’t be taken routinely for prevention unless deficient.
Those friendly bacteria have certainly had their fair share of attention from treating IBS to side effects from antibiotics but is there anything to say athletes should be taking them routinely? There certainly seems to be some promising results if taken daily, at decreasing your chances of catching a cold and lessening symptoms if you do happen to become ill. The big question is which one to take as there are an abundance on the market from drinks to powders and as with most things scientific just because one type has shown benefits doesn’t necessarily mean another will. Most of the studies in athletes have however used readily available yogurt type drinks, which you can find in any supermarket.
So to sum up, your immunity is a complicated system and can be affected by a multitude or factors and as such, there is no one fix wonder. Taking a varied and balanced approach, be it weekly mileage, sufficient rest or meeting your nutritional needs will put you in good stead to stay healthy and lurgy free, whilst remembering a combination of pill popping won’t necessarily help and could be doing more harm than good.