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Myth: Willpower is Limited
Fact: We tend to think of willpower as something that can be depleted. But a growing body of research suggest that isn't so and that we may, in fact, have control over our self control. In a Stanford University study, participants were prompted to regard willpower as either limited or limitless, and then asked to complete a cognitively challenging task. The result: Those who believed willpower was unlimited performed better on a subsequent test of self-control than people who thought the opposite. The next time you worry about your wobbly willpower, just think: It's all in your mind.
make or break bad habits

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Myth: It Takes 21 Days to Make (or Break) a Habit
Fact: Although widely touted, that oft-quoted number has no real science to back it up. "The length of time it takes to establish new habits depends on the person and the complexity of the behavior," says University of Southern California psychology professor Wendy Wood, PhD. So while one study found that participants needed, on average, 66 days to establish new routines (like eating fruit with lunch or drinking more water), the range spanned 18 to 254 days. Bottom line: Don't give up—even if you feel like it's taking you a really long time to find your groove.
make a change

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Myth: Changing Now Won't Make a Difference If You're Too Far Gone
Fact: It's never too late to adopt healthier ways. In a recent study, smokers who quit between the ages of 35 and 44 added about nine years to their lives; even those who waited until their early 60s increased their longevity by roughly four years. The same goes for exercise: A study in the Journal of the American College of Cardiology found that running for even five to ten minutes a day (and at leisurely speeds) can boost life expectancy by an average of three years, regardless of age, BMI or preexisting medical conditions.