How to Build a Strong Immune System

Training hard can lower your resistance. STACK Expert Heather Mangieri tells you how to strengthen your immune system with smart food choices.

Weak immune system

Training hard puts a burden on your body's ability to heal and ward off illness. So let's look at how to build a strong immune system.

During intense and prolonged workouts, your body's stress response rises. As you sprint, make cuts or lift, your muscles actually tear. When your body repairs itself, your muscles grow. However, during this mending period, your body releases signals as if it's wounded, causing inflammation, among other changes. At the same time, the cells involved in immune health are temporarily suppressed.

If you're not getting proper nutrition, your body stays in patchwork mode, weakening your immune system and making you more likely to get sick. Good nutrition also speeds up recovery time, keeping your body in balance and helping you get back to the gym for more quality training.

Here are some nutritional tips to keep your immune system strong between workouts.

Consume carbohydrates before, during, and after exercise 

This has been shown to lower stress hormones and improve immune system function. Aim for 60g of carbohydrates per hour of intense training. For example, consume a 16-ounce bottle of a sports drink before and during your workout and one cup of chocolate milk when you're done.

Eat quercetin-rich foods and supplements

Quercetin is an organic compound found in a number of fruits and vegetables. Studies have shown that quercetin supplements (1,000 mg/day) have anti-inflammatory and anti-oxidative effects on the body. It's nearly impossible to eat enough natural food sources of quercetin to reach 1,000 mg (e.g., you'd have to consume nearly a pound of capers or four pounds of cilantro leaves per day). However, it doesn't hurt to keep quercetin-rich foods in your everyday diet, since these foods are helpful in many other ways as well.

Foods rich in quercetin

  • Onions (includes spring onions & scallions)
  • Apples (especially the skins)
  • Peppers (the hotter, the better)
  • Berries (cranberries, blueberries, cherries)
  • Green vegetables (kale, spinach, asparagus, green peas)

Eat lots of brightly colored fruits and vegetables

Antioxidants called carotenoids give vegetables their bright colors—and your body an immune-system boost.

Photo Credit: Getty Images // Thinkstock