There is a lot of evidence that demonstrates how strenuous exercise, if not managed well through rest, recovery and nutrition can depress the immune system, hindering performance outcomes. Thus, the average baseline for immunity does not suffice and more attention is required in maintaining a healthy system.
In order to optimise immune health and recovery in active individuals, it is important to obtain sufficient sleep each night, ideally around 8 hours. Few people know that Growth Hormone, responsible for physical repair is at its highest around 12-2am. Aiming to get to bed early enough will ensure that you make the most of this. To minimise sleep disruption aim to turn off laptops and phones at least 30 minutes before your preferred sleep time, as the blue light interferes with melatonin production – a key hormone required for quality sleep.
Good nutritional practices are necessary for performance and immune health. While healthy eating guidelines around consuming an increased volume of foods high in anti-oxidants are important, it also pays to focus your attention on all food groups. One of the key aspects of sports nutrition is tailoring requirements to training needs; so as load and intensity increases then nutritional intake will also need to marry this for optimal outcome.
With regards to nutrition it is vital to consume a sufficient number of carbohydrates throughout the day, particularly in high intensity or volume training blocks. This not only ensures appropriate fuelling for the body but also helps prevent the suppression of the immune system, which can be a result of inadequate fuelling.
As a recommendation aim for a third of a plate at every meal of wholegrain nutrient dense carbohydrates such as sweet potato, pasta, rice etc. on training days and a quarter plate on non-training days.
While you can obtain most of the nutrition you need through your diet, there are two supplements that are worth considering, especially during the winter months and in the lead up to major races.
One of the main challenges, especially for UK based athletes due to the limited/lack of sunshine, is to ensure enough Vitamin D, therefore regular monitoring is advised. Vitamin D is a very important nutrient when it comes to immune function and mood. Luckily it is very easy to supplement through the winter months. For individuals who are highly active a serum Vitamin D level of above 75 is recommended, anything under this should be supplemented – if levels are below 50 then aim for 4000 IU a day; if levels are 50-75 then aim for 1000 IU a day.
Numerous studies have demonstrated that a 12 week course of high strength probiotics can prevent the incidence and reduce the severity of upper respiratory tract infections in athletes in the lead up to and after a major competition (Gleeson & Thomas 2008, Cox et al 2010; Gleeson et al 2011; West et al 2011, 2014). One of the most critical times to boost your immune health is in the two weeks immediately post an endurance event as this is when your immune system is significantly depressed.
Regularly monitoring the levels of iron, ferritin, B12, thyroid function, vitamin D and white cell count in the blood is important to understand how the immune system is functioning, especially during high volume and/or intensity training blocks. With this knowledge, strategies can be implemented to ensure the best possible health for each athlete.
In addition to food, hydration plays a critical role in immune health. Hydration should not be ignored as it encourages the production of saliva which contains high levels of IgA; the body’s first line of defence. While good hydration is usually easy in the summer months, it is a challenge in the winter when many athletes find it more difficult to drink. Herbal teas, no added sugar squashes and flavoured waters can all encourage the consumption of fluid to maintain hydration levels.