It’s Fall—back-to-school time! And for me, and many parents, that means back-to-me time…time for taking care of all the piles of stuff over the summer I never got done and getting back on track with my exercise and eating healthy routines.

But there’s one hitch to my best intentions: with cooler weather and the kids back in school comes the tendency to get sick more. That’s because we’re spending more time indoors with re-circulated—instead of fresh—air, which more easily spreads any viruses present. Indoor air is also less humid and this, in turn, dries out the nasal passages, making them more vulnerable to infection.

But what I’ve found is that—despite whatever viruses are lurking indoors (and with three kids that tends to be a lot!)—when I’m really making an effort to stay healthy: exercising regularly, eating plenty of nutrient-rich fruits and vegetables, and getting at least eight hours of sleep a night, I get sick much less.

Research seems to back up my theory; here are the lifestyle tweaks that experts have found help keep our immune systems strong—and us healthier:

  1. DON’T over sanitize everything in your world. Our immune systems stay strong, say experts, by being constantly challenged; over sanitizing can actually have the opposite effect of reducing immunity by getting rid of the germs that our immune systems need to get strong. The bottom line: plain old soap and water works best. My one exception: the kitchen counters and sink where food-borne infections like salmonella and e-coli can lurk from raw eggs and meat. (I use part bleach, part water in a spray bottle and/or sanitizing wipes to disinfect these surfaces.)

  2. DO eat some sauerkraut or Korean kimchi. These fermented foods contain substances called prebiotics that promote the growth of good bacteria in your gut (probiotics—found in yogurt—can also do this), and this—in turn—helps your immune system fight off germs and viruses.

  3. DON’T eat a lot of sugar. This is hard, as cooler weather seems to trigger the comfort food munchies in even the healthiest of us. One study, done at Loma Linda University in California and published in the American Journal of Clinical Nutrition, found that when volunteers ate 100 grams of sugar (about 20 teaspoons, about the amount in a liter of soda), infection-fighting white blood cells in their blood gobbled up many fewer bacteria than in those volunteers who didn’t eat the sugar.

  4. DO have a good laugh, as often as you can. Some studies show that people who lack humor in their lives tend to have less protective immune systems. The reason? Laughing helps reduce stress, which research has shown suppresses immune function.

  5. DO stay positive. Positive, pleasant events—and having an optimistic, upbeat attitude—seem to offer a small boost to the immune system that can last for up to two days afterward. (For other ways to tame stress, click here: http://www.centrum.com/expert-corner/health-articles/stress-relievers-top-10-picks-to-tame-stress.)

  6. DO get enough vitamin D. Sunlight boosts vitamin D—which is critical to supporting the immune system. You can also get vitamin D from foods like milk, eggs, salmon, or tuna—as well as from a multivitamin like Centrum® Women or Centrum® Men.

  7. DO exercise. Regular exercise improves the function of your heart, lungs, and every aspect of your body—including your immune cells. The result? Your immune system is better equipped to fight bacteria that could make you sick.

  8. DO eat chicken soup. One study in the journal Chest♦♦ found that eating chicken soup can help lessen the inflammatory response behind colds and flu. But not only that, eating plenty of fruits (like blueberries) and vegetables (like broccoli) go a long way to help support your immune function.

  9. DO get some sleep. Sleep is restorative; according to the National Sleep Foundation, when you get enough sleep, breathing slows, muscles are relaxed and blood supply to the muscles increases, tissue growth and repair occurs, energy is restored, and hormones that aid in growth and development are released. But not getting enough sleep (less than five hours a night) can increase stress hormones and depress the immune system.

How Many Hours of Sleep Do You Need? Some people seem to do fine on 6 hours, while others need 9 hours of shut-eye a night. Click here: http://www.centrum.com/expert-corner/health-articles/how-many-hours-of-sleep-are-enough to figure out what you need—and why.

J. Albert Sanchez, L. Reeser, H.S. Lau, et al., “Role of Sugars in Human Neutrophilic Phagocytosis,” The American Journal of Clinical Nutrition, 26 (11), 1973, 1180-1184; http://ajcn.nutrition.org/content/26/11/1180.abstract.

♦♦B.O. Rennard, R.F. Ertl, G.L. Gossman, et al., “Chicken Soup Inhibits Neutrophil Chemotaxis In Vitro,” Chest 118 (4), 2000, 1150-7; http://www.ncbi.nlm.nih.gov/pubmed/11035691.