’Tis the season for the flu, winter colds, and other upper respiratory infections (URIs) that put a damper on our workouts and threaten our fitness. During periods of heavy training and racing, athletes are more susceptible to an increase in these infections. A 3- to 72-hour window exists following prolonged or heavy exertion where many components of the immune system exhibit change—an opportunity for viruses and bacteria to gain a foothold. In addition, factors such as travel, low energy availability, and high levels of stress and anxiety also put athletes at risk. Add a COVID-19 Omicron surge into the mix and it might feel like the most dangerous season of the year.
How to Boost Your Immune System
So, what can we do from a nutritional, training, and lifestyle standpoint to combat getting sick? Here are some action items to keep running strong.
There are several strategies that you can follow to improve your immunity as an athlete. These include a handful of key supplements. Of course, talk to your healthcare provider before altering your supplementation, but those that have strong support in literature are vitamin D3, probiotics, vitamin C, and zinc lozenges.
- Consider taking 1000 IU/day of vitamin D3, from fall to spring, to avoid insufficiency.
- Consider probiotics (>1010 live bacteria/day; Greek yogurt is a great food-based source) if you are illness-prone or while traveling.
- At the onset of a cold, take zinc acetate lozenges (75 mg/day) to reduce the duration of symptoms—must be taken < 24 hours after onset.
- Also consider 0.25–1 g/day of vitamin C to decrease URI incidence, as well as reducing URI duration, if initiated after the onset of symptoms.
In addition to supplementation, there are also several general nutrition habits that support a healthy and strong immune system:
- Eat a well-balanced diet with a focus on fruit and vegetable consumption (5–7 servings/day) to provide adequate nutrient density.
- Consume >50 percent of daily energy intake as carbohydrates.
- Consume an adequate amount of protein (1.2–1.6 g per kg/day).
Managing overall stress (that includes physical) also plays a large part in immune health. Some training principles to abide by, that will ultimately keep you healthy, both from injuries and from upper respiratory infections, include:
- Follow a proper periodized training program that allows for a recovery week after every two- to four-week build period.
- Keep volume and intensity increases limited to 5–10 percent per week (maximum), especially during the winter months.
- Schedule recovery days (and ensure that these days are truly easy—heart rate training is good for this) following high-intensity sessions or days.
- Do not train with below-the-neck symptoms.
Making sure you don’t get rundown in daily life and following some simple principles with regards to travel and sleep can also hugely impact your body’s immunity. It is a well-understood concept that psychological stress has a large influence on immunity and resistance to infection.
- Aim for at least seven hours of sleep each night. You cannot “catch-up” to multiple bouts of restricted sleep; consistency with sleep is king. If possible, daytime naps can be beneficial.
- Although easier said than done, keeping life/psychological stress to a minimum can also play a big role in staying healthy. This may mean reducing training stress during periods of high life-stress or travel, to manage your overall stress load.
- Avoid sick people, and mask up. It sounds simple, and it is. When exposed to those with URIs, do not underestimate the importance of thoroughly washing your hands in order to avoid self-inoculation by touching your eyes, nose, or mouth.
It is possible to remain healthy and train strong throughout these tough winter months. A focus on nutrition, sound training principles, and overall stress management can be a great start toward fortifying your immunity and overall well-being.
Beth Peterson RD, CSSD, LDN is a Registered Dietitian and Board Certified Specialist in Sports Dietetics.