Winter means hard training and illness for many young swimmers. Any illness is a setback, pulling the swimmer out of the pool for days, a week, or even longer.

Some factors hurt the immune system’s ability to function well, such as lack of sleep, poor nutrition, getting exposed to new germs, mental stress, and even weight loss. When the immune system isn’t working well, the swimmer may be more susceptible to illness.

One area swimmers can focus on is nutrition. Fruits, vegetables and whole grains are essential to an immune-boosting, healthy diet. Whole foods offer a complex array of vitamins, minerals, antioxidants, phytochemicals, and more, helping to ward off illness year-round.

Add some of these immune-boosting foods in your daily eating routine:

Yogurt: Yogurts that contain probiotics, noted on the label by the phrase “Live and Active Cultures,” may increase the presence of good bacteria in the intestinal tract and bolster the immune system. Some yogurts also contain vitamin D (listed on the Nutrition Facts Panel as a percentage; 20% or more is considered a good source of vitamin D), a nutrient that when deficient is associated with an increased risk of cold and flu.

Dark-colored Berries: Berries that are dark or bright in color, such as blackberries and blueberries, contain a flavonoid called anthocyanin. Anthocyanin may strengthen the immune system and fight disease.

Almonds:  Many nuts contain vitamin E, which is an antioxidant. Antioxidants slow down the process of cell damage and may boost the immune system.

Oats or Barley: Oats and barley contain a special fiber called beta-glucan, which is an antioxidant and an antimicrobial (a substance that fights harmful micro-organisms).

Sweet potatoes: Sweet potatoes are rich in vitamin A, also an antioxidant, which helps to build connective tissue like skin. Skin is the first line of defense for fighting bacterial and other infections.

Grapefruit: Grapefruit contains vitamin C, an antioxidant, and is also loaded with flavonoids (plant pigments), which help to activate the immune system.

Beef: Beef is a good source of zinc for the athlete. Zinc helps white blood cells develop.  Swimmers with even a mild deficiency of zinc have been shown to be more susceptible to infection.

Jill Castle, MS, RDN is a registered dietitian, childhood nutritionist, and youth sports nutrition expert. She is the author of Eat Like a Champion: Performance Nutrition for Your Young Athlete. Learn more about Jill at www.JillCastle.com.