What are the most important nutrients for keeping your immune system healthy? 

Infections can be a nuisance for athletes; you’ve just banked a good solid block of training and then the, all too familiar, sniffles or sore throat appears.

Sometimes they don’t develop into anything more, but can lead to symptoms that causes you to take a few days off from training.

We rely on an effective immune system to fight off these infections, and nutrition play a vital role in helping it work effectively.

Firstly, it’s important that your immune system is supplied with enough energy to fight off viruses and bacteria. That means eating enough calories!

Ideally you should aim to be in energy balance, which you can check by making sure your weight remains stable over days or weeks.

These calories should come from a wide range of foods, and remember to ‘eat your rainbow’, and get as many different colours from different fruits and vegetables into your diet as possible.

• Are you eating enough for training and racing?
• What’s the difference between fruit and vegetables, and which are best for athletes?

Vitamin C plays an important role in the immune system by improving tolerance to infections, and you should look to include foods such as oranges (and their juice), bell peppers, kiwifruit and strawberries.

Next, make sure you are eating enough protein, as a triathlete needs to eat about 1.5 times their bodyweight in protein (per day). Adequate protein helps muscles recover from training, but also supports the production of antibodies and immune cells.

• Protein: how much do you need?

What about supplements? Vitamin D is known to play a part in a healthy immune system. During the winter months where we see next-to-no sun, I’d recommend supplementing with 2000 IU per day.

You could also take a daily multi-vitamin to make sure you’re getting the RDA of vitamins. If you do feel a cold coming, supplementing with zinc lozenges (75 mg//day), has been shown to reduce the length of a cold.

• What are the most important nutrients endurance athletes need in their diet?
• Diet nutrient split: what’s the right balance for triathletes?
• Vitamin E: What is it and why is it important to athletes?
• The vitamin B complex: Why are the B vitamins important to athletes, and should you supplement?
• Why can you experience loss of appetite during training?

Stephen Smith Performance nutritionist

About

Stephen Smith (PhD, SENr) is performance nutritionist for Red Bull Athlete Performance Centre in Salzburg and tutor at the Institute of Performance Nutrition. He believes in a food first, evidence-informed approach to maximising the health and performance of athletes. He's passionate about providing relevant, easy-to-understand educational support to turn the science into applicable nutrition practice that improves health and performance. He's also committed to developing quality sports science and nutrition research that informs practice and ultimately improves the performance of athletes.