Runners – Are you Killing your Immune System?

November 29, 2018

Are you catching every cold that comes your way, yet determined to keep running?   Continue reading to learn how to Beat the Immune Battle.

Exercise, particularly running longer distances or intense work outs, can be a stressor on your system. The recovery phase from intense exercise has shown lower levels of lymphocytes in the blood. Lymphocytes are found in your white blood cells and are suppressed during infections, particularly viral infections. This triggers a cascade in immune reactions resulting in increased levels of inflammatory cytokines in the blood resulting in simultaneous inflammation and a temporary suppression of the cellular immune system. The most pronounced findings being 2-4 h after the exercise [i].   These reactions involve the neurological system, hormonal influences and metabolic factors. This in combination with fluctuations in weather temperatures plus cold and flu season are a recipe for muscle damage and illness!

So what’s a runner to do?

  1. Rest
    • The one thing runners won’t do is STOP! You need to give your body time to recover, especially when exercise can aggravate an illness. Muscle recovery is also enhanced when appropriate rest times are scheduled in.
  2. Probiotics
    • Probiotics are live micro-organisms that when administered orally for several weeks can increase the numbers of beneficial bacteria in the gut. These have been associated with a range of potential benefits to gut health, as well as modulation of immune function. A Cochrane review shows ~ a 50% decrease in Upper Respiratory Symptoms and ~ two day shortening of illnesses[ii]. Probiotics are generally well received with minimal side effects.   Lactobacillis Plantarum can be beneficial for modulating inflammation while Bifidobacterium strains can help support a health immune system[iii]. Ask your Naturopathic Doctor which strain is best for you.
  3. Zinc
    • A deficiency in zinc in not unheard of in athletes. Zinc is an enzyme cofactor for immune cells, therefore a deficiency can result in impaired immunity and more frequent colds. A Cochrane review shows a benefit when zinc is taken less than 24 hours after the onset of Upper Respiratory Symptoms[iv]. High doses and long-term use of zinc is not recommended without medical supervision as this can impact healthy copper levels. Side effects of Zinc supplementation can include bad taste and nausea.
  4. Vitamin D3
    • A deficiency can affect many systems in our body, including gene regulation. A decrease has been associated with Upper Respiratory Symptoms. Athletes are at risk of insufficiency, particularly in the winter months when training may be taken indoors. Skin exposure from sunlight can account for 90% of our absorption of Vitamin D[v]. Vitamin D is fat soluble, so those on low fat diets or with difficult digestion may not be absorbing as much as they think. Your Naturopathic Doctor can run a simple blood test to determine your Vitamin D levels. For those that are deficient or sick, a body weight algorithm can be used to determine safe dosing as toxicity is possible.
  5. Glutamine
    • It is an important amino acid. It is a building block of protein that has offers runners a Health Hat Trick – helping with muscle recovery, immunity and intestinal health. Athletes with heavy training loads are prone to infectious illnesses, suggesting that their training may suppress immune function. A study published in 2015, measured athletes Natural Killer cell activity and immune responses. They found that glutamine was lowered with longer exercise sessions and supplementation may be able to restore immune function and reduce the immunosuppressive effects of heavy-load training[vi].

I believe Food is Medicine. Here are 3 of my top food picks to support a Runner’s Immune System:

  1. Red Cabbage
    • has sulphur containing compounds that can support a healthy immune system. Do you find you are getting sick after long runs? Add 1 cup shredded red cabbage into salads and stir fry’s to fend off colds.
  2. Kiwi
    • 100g of this fuzzy little fruit contains 92.7mg of Vitamin C (approx. 1.5 kiwis). Compare that to an orange at 53.2mg[vii]. Vitamin C is essential to the formation and repair of tissue – particularly cartilage, blood vessels, tendons and skin – all of which are essential to the survival of a runners body. Did you know you can eat the skin? Mix up an Avocado Kiwi Salsa for tendon support.
  3. Garlic
    • More than 100 biologically-useful chemicals are in this germ fighting ninja with the most common being allicin. These compounds can boost your immune system by increasing the rate at which your natural killer cells are made. Garlic has been shown to protect against the common cold and can help fight off harmful bacteria, viruses and even yeast infections. Garlic has also been shown to reduce homocysteine levels in the blood. High levels of homocysteine are associated with elevated inflammatory responses and are directly linked to high cholesterol levels and cardiovascular disease[viii]. If you can’t stand having garlic breath in the office, supplement form can offer higher concentrations with a greater therapeutic threshold. Garlic Scape can enhance the flavour of your recipes. If you haven’t tried this version of garlic you have to head out to your local farmers market and give it a go! Check out Julie Daniluk’s twist on a Ceasar Salad below.

If you find you can’t kick your cough or cold, link in bio to book and begin your journey to becoming stronger inside.

Immune-boosting Caesar Salad from Julie Daniluk.

  • 1 head Romaine hearts (1 heart = 232 g)
  • 1 head purple endive, leaves separated (1 leaf = 15 g)
  • 1/2 fresh pineapple, diced
  • 10 flax crackers (gluten-free if possible), broken into pieces
  • 1 tbsp capers
  • 1 tbsp Parmesan cheese, grated (optional)
Caesar dressing:

Makes enough dressing for two to three salads so store leftovers in the fridge and consume quickly.

  • 1/2 cup olive oil
  • 2-3 cloves garlic
  • 1 celery stalk, chopped fine
  • 1/4 cup water
  • 2 tbsp lemon juice
  • 1 tbsp wheat-free tamari
  • 3 anchovy fillets
  • 1 date (1 tsp of honey works if dates are unavailable)
  • 1/2 tsp nutritional yeast (optional)
  1. Wash and dry romaine hearts and endive leaves.
  2. Chop pineapple and layer on top of the greens. Top with a light dusting of capers, flax crackers and grated hard cheese if desired.
  3. Using a blender, whip all the dressing ingredients together.
  4. Top the salad with the dressing and enjoy.

Makes two full salad servings.

The information provided is for informative purposes and is not intended to substitute professional medical advice, diagnosis or treatment.


[i] Pedersen BK1, Rohde T, Ostrowski K. Acta Physiol Scand. 1998 Mar;162(3):325-32. Recovery of the immune system after exercise. PMID: 9578378 DOI: 10.1046/j.1365-201X.1998.0325e.x.





[vi] Song QH, Xu RM, Zhang QH, Shen GQ, Ma M, Zhao XP, Guo YH, Wang Y. Int J Clin Pharmacol Ther. 2015 May;53(5):372-6. doi: 10.5414/CP202227. Glutamine supplementation and immune function during heavy load training.


[viii] Daniluk, Julie. Meals That Heal Inflammation.

Dr. Jennifer Tanner, has a broad, evidence-based practice with a focus on sports and performance-based medicine. Being a marathon runner and having been a competitive equestrian, an active lifestyle is important. Dr. Tanner uses a variety of tools including Acupuncture and Clinical Nutrition, putting an emphasis on “food as medicine” and addressing the root causes of inflammation. In conjunction with the Integrative Health team, Dr. Tanner is thrilled to help people achieve an optimal state of health and pursue their performance based health goals!


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