It’s that time of year again. You might be hearing a hacking cough outside your office or a sniffle and sneeze coming from your own living room. Sometimes it feels like catching the latest bug is inevitable. But a new study shows that moderate exercise can help ward off whatever is going around. Even if you’re not currently in a fitness regimen, starting a routine now can help you avoid winter’s worst bugs according to this recent research.

David C. Nieman, former president of the International Society of Exercise and Immunology, conducted a study on the effects of exercise on the immune system. He found that cells from the lungs, spleen, and bone marrow experienced a surge in circula­tion in subjects who completed moderate exercise. That means that when you’re moving, your immune cells are moving too. The study also showed that this circulation had a cumulative effect, keeping active people more healthy year-round. Neiman’s research tells us that moderate aerobic exercise such as brisk walking, cycling, or jogging done in 30 minute sessions 5 days a week can help fight off viruses and bacteria by boosting the body’s immune system. So how can you get this free immunity?

The key is finding a fitness routine that works for you. If you’re new to fitness, a good starting point would be to take a half hour walk every week day. You might find time to head outside during your lunch hour, or if the weather is bad you can set your phone alarm and climb the stairs until you hear the “beep of freedom.” Since group time can make exercise more fun, you might ask friends in the office or on the block to join you for a “Challenge 150.” See who can collect the most weeks of 150 minutes worth of aerobic activity. The Centers for Disease Control website also offers several other techniques for integrating your 150 minutes, including swimming laps, playing basketball, and playing doubles tennis.

Along with exercise, Neiman also recom­mends taking care of ourselves in the following ways: getting plenty of sleep, monitoring stress levels, practicing good nutrition, and being aware of germ sources including the air in confined spaces and on our own hands.