If you think the only focus of sports nutrition is to improve performance, think again. Keeping athletes healthy and able to compete is priority numero uno (no one cares how well you perform if you’re stuck on the sidelines), and when training gets tough, adequate nutrition becomes even more important.
For normal, healthy individuals, regular exercise at moderate intensity reduces the risk of illness. Athletes, however, are often exposed to intense training and/or competition, which, as a result of something called exercise-induced immune-depression, can lead to illness.
While this is an unfortunate side-effect of prolonged and intense exercise, there are several nutritional strategies that can help an athlete maintain robust immunity and limit this susceptibility to illness (as well as other strategies that I’ll mention, but don’t have enough expertise to truly comment on).
When an athlete undergoes a prolonged bout of strenuous exercise, there is a depression in immune function that typically lasts up to 24 hours. It is hypothesized that this creates a window of opportunity for viruses and bacteria to gain a foothold, increasing the risk of infection. In fact, there are several studies that show an increase in the incidence of upper respiratory tract illness symptoms in the days after such events. It’s also been shown that periods of intensified training (lasting a week or more) can chronically depress immune function, compromising resistance to common minor illnesses.
It may seem that upper respiratory tract illnesses (i.e. the common cold) and their associated symptoms (e.g. sore throat) are insignificant, but they often interrupt training, causing athletes to under-perform and miss competition. In a survey of hundreds of athletes from Great Britain, infection (and usually of the upper respiratory tract) was responsible for a surprising 33% of reasons for missing training.
The bottom line is that it all comes down to stress. The magic formula to a sick and under-performing athlete is a combination of physiological stress (i.e. intense training), psychological stress, environmental stress (i.e. pollutants), poor sleep, and an inadequate diet.
It’s up to your coach, trainer, sports psychologist, and you to tweak the other factors, but if you want be a top-performing, healthy athlete, hear us out on what you need to be doing nutrition-wise.
1. Eat enough calories. Match your intake to your activity level, so that your caloric intake equals expenditure. Have a harder workout day? You need to eat more. Monitoring weight can be an easy way to determine if you’re intake is adequate. If the number on the scales moves down in-season, you aren’t meeting the demands of training! Time to fill up that plate….
2. Eat enough protein. Protein is more than just for building strong bodies. Yes, inadequate protein intake will lead to muscle wasting, but it can also lead to a decreased number of immune cells which = increased risk of infection. While this number can be highly individualized, a good rule of thumb for athletes is to consume 2 grams of protein per kilogram of body weight (divide your bodyweight in lbs by 2.2 to get weight in kg).
3. Eat adequate micronutrients, particularly iron, zinc, Vitamin A, D, E, B6, and B12. Confused about how to get all those in? Eat whole foods as much as possible and don’t stick to the same foods all the time. Whole grains, meat, fish, legumes, vegetables, fruit PLUS variety. Those should be your staples. Take a multivitamin if you’re having a rough week (when food quality and quantity is limited), but try not to rely on one.
4. On second thought, we’re highlighting Vitamin D again. Vitamin D plays an important role in up-regulating immunity, yet vitamin D is commonly LOW in athletes. To optimize immune function, a vitamin D supplement may be warranted, so chat with a qualified nutritionist or doctor.
5. Hydrate appropriately, especially during exercise. Hydrating during exercise is KEY to avoiding dehydration and maintaining saliva flow rate. You may be surprised to learn that saliva contains several anti-microbial proteins, and while secretion usually decreases during exercise, appropriate fluid intake can prevent this. Dehydration also leads to an increase in stress hormones, which depress the immune system further. And finally, if you needed more convincing, overheating can increase gut permeability, which may allow entry of gut bacterial endotoxins into circulation. Staying hydrated helps keep your core temp down!
6. Eat adequate carbs before and during prolonged exercise (>1.5 hrs). The lower your carbohydrate ingestion, the more substantial degree of immune suppression will occur. Note: this does not mean eat ONLY carbs (hint hint at the importance of working with a nutritionist to individualize this). Generally, an intake of 30-60g per hour during intense, prolonged exercise is advised, as well as adhering to a high-carbohydrate diet when undergoing intense training.
7. Take or eat probiotics. Much of your immune system is governed by your gut bacteria. A few studies even show that daily doses of live bacteria (probiotics) can reduce the incidence of upper respiratory tract illness symptoms in highly physically active people. Incorporate foods like yogurt, kefir, buttermilk, sour cream, kombucha or other probiotic drink, miso, and any pickled or fermented vegetables (like sauer kraut) daily.
8. Don’t ignore post-exercise fueling. Because immune function is compromised after heavy training/competition, refueling with carbohydrate, protein, and fluids helps to restore function. If you don’t have a post-exercise feeding plan, it’s time to develop one.
9. NO crash diets or rapid weight loss. For immunity’s sake or not, this is never the answer. Athletes undergoing weight loss are more likely to be prone to illness. For the right way to lose weight (gradually and sustainably…and with minimal loss of muscle mass), work with us or your favorite qualified nutritionist.
Yes, that's a lot to get right. Working with a nutritionist will help you assimilate these strategies to your lifestyle and individualize them for your sport and unique needs. Follow these, make them a part of your routine, and you will minimize your risk of getting sidelined by illness. Contact us