7 smart ways to avoid the common cold

The cold virus is small but mighty—it can knock you down in an instant—and leave you stuck in bed for days. Fight back the smart way with these proven tips.

• Do this even if your hands don't look or feel dirty. Scrubbing five times a day with soap and water slashed the number of upper respiratory infections among US Navy recruits by 45 percent in one two-year study.
• A brisk, 10-second scrub rinses away 99 percent of viruses. This cuts your odds of infection substantially, but not completely; a single viral particle can start a cold!
• For best results, wet your hands, lather vigorously for a full 20 seconds, rinse and dry with a clean paper towel. Use the towel to turn off the tap, too. Any soap will do—washing works by scrubbing viruses off your skin, not by killing them (and antibacterial soaps don't kill viruses anyway).

• When you can't reach a sink, sanitizer gels and sprays kill bacteria and some viruses, but don't put all your eggs in this basket.
• Studies show that brands containing 60 percent ethanol alcohol are powerless against rhinoviruses (which cause colds). Some researchers report that a 70 percent ethanol sanitizer can be effective.

• Regular exercise invigorates your immune system's natural killer cells and virus-killing antibodies.
• University of South Carolina researchers found that adults who exercised moderately to vigorously at least four times a week had 25 percent fewer colds over one year than those who moved less. A brisk 40-minute walk five days a week should do it.
• In another study, this much exercise cut in half the number of days volunteers had cold symptoms. But don't overdo it: working out for an hour and a half or more could reduce immunity.

• Moist nasal passages are less receptive to cold viruses than dry ones. In one 20-week study of US military recruits, those who used a saline nasal spray every day had 30 percent fewer colds and 42 percent fewer days with runny noses or congestion.
• Key times to spritz: in winter, when heated indoor air is dry and during airplane flights.

• In a year-long Spanish study of 1,149 university professors and staff, sniffles were twice as likely among people who felt the most stressed, or reported experiencing the most stressful events compared to those with the least. And once you catch a cold, stress can make symptoms worse.

• This ancient remedy may help by boosting the activity of your immune system's virus-killing T cells.
• When 146 women and men took either a garlic capsule or a placebo pill daily during cold season, the garlic group caught 24 colds, while the placebo group got 65. Researchers at England's Garlic Centre say that garlic takers who did get sick recovered in just 1.5 days, while the placebo group had the sniffles for an average of five days.
• Other research, however, is less positive about garlic. If you love garlic, use it liberally. Remember to "chop, then stop:" let chopped or crushed garlic sit for 10 minutes before using to maximize levels of its most active component.

• In an Austrian study, people who did this twice a week for six months had half as many colds as those who didn't use the sauna.
• The link may be air temperature. At over 27°C (80°F), sauna air is too hot for cold viruses to survive.