By Dr. Luke Bucci, PhD

Photo Credit: @piperalbrecht

It’s that time of year again. After all the traveling, gathering, and celebrating of the holiday season means with Holiday Cheer comes post-Holiday Fear of illness – even for those of us who partook of none of the above. This worry is compounded by the very normal and expected-but-unwanted risk of exercise-induced URS (Upper Respiratory Symptoms) that endurance athletes face year-round. Strenuous training exposes the body to increased risk of illness, and the annual arrival of cold & flu (& now COVID-19) season means there’s plenty of illness to go around.

The past few years have seen intense research conducted and published on long-term endurance exercise and changes in your immune system associated with URS (Nieman 2019 201, 2019 341; Peake 2017; Walsh 2019). Surveying this research helps explain the causes and complications while providing avenues for athletes to avoid them – or at least mitigate the risk of exposure.

For practical purposes, if you have URS after strenuous, long-term exercise in the cold, you may have some kind of URTI (Upper Respiratory Tract Infection) – or at least be setting yourself up for one. Whether you are knocked out for days afterwards or just feeling suboptimal, the difference is semantic. URS happens throughout the year, but we are all focused on Upper Respiratory health in the winter, so let’s get on with what to do about it.

Scientists have yet again found the obvious: No or too much exercise means more URS and problems. This is shown in Figure 1 by a classic J-shaped curve of URS vs. exercise intensity.

Figure 1: Strenuous exercise increases URS (Upper Respiratory Symptoms) by 2-6 fold over no exercise (Adapted from Blocher et al, 2013). For endurance events, that works out to a 10-20% chance of being adversely affected by URS, year round.

Fortunately, there are ways to support your immune system even while your training lifestyle is constantly taxing it. Many of the nutrient items recommended by a review of scientific literature on the subject can be met with different elements in the First Endurance system – glutamine and BCAAs in Ultragen, Vitamin D and immune-supportive beta glucans in MultiV, and curcuminoids in HALO.

Whether by necessity or personal choice, not all of these items are viable for everyone, so the best recommendation is to pick and choose as many from column B as possible while also avoiding as much of column A as possible. Ultimately, like with meeting the requirements of a training plan, the choice on what you do and don’t do is up to you; however, doing the right things as well not doing the wrong things can add up to better immune function and a healthier you.

TABLE: Ways to Reduce Exercise-Induced URS – Do’s & Don’ts

Consuming alcohol (especially too much) Balanced diet with thoughtful portions
Close physical contact Caffeine (coffee, black & green teas, supplements) but not excessive
Crowds, enclosed spaces Carbs, Electrolytes, Hydration during long-term exercise
Clubs & gym facilities with poor ventilation Carbs with protein immediately after exercise (even better with electrolytes & amino acids (glutamine & BCAAs)
Sharing drinking or eating implements Oral zinc acetate lozenges for URTIs (follow directions carefully) – dissolve in mouth, do not swallow whole
Internalizing negative life events & emotions Plenty of fruits and vegetables from diet for polyphenols
High doses of Vitamin C (500mg) during exercise Polyphenols from berries, green tea, curcumunoids, and maybe others
High-dose Vitamin E supplements (alpha-tocopherols >100 mg daily) Prebiotics which are more universally effective than probiotics.
Nasal zinc products for URTIs or extra zinc supplements (outside of a multivitamin) Allow sufficient recovery between strenuous exercise sessions
Sneezing, spitting, hacking, coughing, blowing snot/phlegm on you or open surfaces Sleep! (1-10mg melatonin just before bedtime helps sleep quality)
NSAIDs (non-steroidal anti-inflammatory drugs) aspirin, ibuprofen, naproxen) – can use acetaminophen for pain relief but not with alcohol Techniques to actively manage stress
Touching your face (it’s self-inoculation!) Vitamin C (not before, during, or immediately after exercise) – up to 1,000mg daily while training or 3,000mg daily (3 x 1,000mg) while not training if experiencing URS
Training during URS or when ill Vitamin D supplements – up to 5,000 IU (125mcg) daily
  Wash hands regularly & effectively (this means with soap, detergents, or disinfectants)
  Wear masks in public places
  Yeast Beta glucans, not oat beta glucan (take daily at recommended amounts)



Blocher JC, Bodland SE, Cox DJ, McFarlin BK, Moriyama H, Shiojima Y. Nutrition intervantions to reduce immune suppression post-marathon. Ch 32 in Nutrition and Enhanced Sports Performance. Muscle Building, Endurance, and Strength. Bagchi D, Nair S, Sen CK, Eds., Academic Press, London, UK, 2013, pp. 325-31.

Nieman DC, Lila MA, Gillitt ND. Immunometabolism: a multi-omics approach to interpreting the influence of exercise and diet on the immune system. Annu Rev Food Sci Technol. 2019 Mar25;10:341-63.

Nieman DC, Wentz LM. The compelling link between physical activity and the body’s defense system. J Sports Health Sci. 2019 May;8(3):201-17.

Peake JM, Neubauer O, Walsh NP, Simpson RJ. Recovery of the immune system after exercise. J Appl Physiol (1985). 2017 May1;122(5):1077-87.

Walsh NP. Nutrition and athlete immune health: new perspectives on an old paradigm. Sports Med. 2019 Dec;49(Suppl 2):153-68.

October 02, 2023 — Luke Bucci

Leave a comment

Please note: comments must be approved before they are published.

Did you find this post interesting and valuable or was it a waste of your time? Do you have a topic you’d like us to cover or a question you’d like answered? If so, leave a comment below and we'll get back to you right away.

    1 out of ...