2. They sleep.
Most Americans, and people worldwide too, don't sleep enough. 8 to 10 hours of sleep is what is needed for you to remain healthy.
Getting enough sleep is absolutely required for maintaining a strong immune system that can ward off nasty bugs. Studies have shown that people who get less than 7 hours of sleep a night are 30% more likely to catch a cold when exposed.
3. They think it away.
The brain is the strongest defense against nearly everything. If you simply think and believe you wont' get sick, you'll naturally be less likely to become ill. Nice!