Exercise less! Ignore expiration dates! These new-and-improved guidelines might just surprise you.
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Getty ImagesEveryone from government agencies to your mother is constantly telling you about the "right" steps to take for your health. So you'll be glad to hear that there are some so-called laws you can actually blow off—and doing so can be not only easier but also more effective than toeing the good-for-you party line. Not to mention, these little rebellions are totally backed by the latest science. We think you're going to like being a rule-breaker.

The rule: Do at least 30 minutes of moderate exercise five days a week.
The new thinking: Up the intensity and you can cut your workout time in half (or more!).

You'll love this recent research discovery: The cardiovascular benefits experts used to believe you could get only via half an hour of a medium-intensity activity (like jogging or a brisk walk) can also be scored by doing much shorter, less frequent spells of high-intensity interval training, or HIIT, which alternates quick bursts of crazy-vigorous exercise with brief recovery periods.

Those super short intervals trigger metabolic changes not seen with more moderate activity, explains Yuri Feito, PhD, assistant professor of exercise science at Kennesaw State University in Georgia. These changes seem to make the heart more efficient at pumping oxygen-rich blood to muscles, leading to bigger health gains than you'd get from less intense training—in a fraction of the time of a traditional workout.

The best part? There's no right way to do HIIT. The moves can be equipment-based (runs on a treadmill) or gear-free (jumping jacks). And it's adaptable to all fitness levels. If you're a newbie, try alternating 15 to 30 seconds of moves with 15 to 30 seconds of rest; a pro might go hard for one minute, then stop for 30 seconds or less.

The American Heart Association supports the power of intense exercise, recommending 150 minutes of moderate activity—or 75 minutes of vigorous activity—a week. But many researchers and trainers say doing 10 minutes (that includes the intervals plus rest time) three times a week is as effective—as long as you're pushing yourself. Says Craig Ballantyne, author of Turbulence Training: "Interval training is supposed to be taxing— but it's easier to stay with, so people enjoy it."

The rule: You always need a solid seven to eight hours of sleep.
The new thinking: Go ahead, stay up late—you can make up for it.

Doctors used to warn that if you lose out on sleep, you can't catch up. New science to the rescue: "If you've skimped on sleep a couple of nights in a row, research shows that you can absolutely catch up by getting more shut-eye over the next day or two," says Christopher Winter, MD, medical director of Charlottesville Neurology and Sleep Medicine in Virginia. To do so, turn in early and wake up at your normal time rather than sleeping late the following day. "Sleeping in throws off your regular cycle and sets you up for more restless nights," says sleep specialist and clinical psychologist Michael Breus, PhD.

The caveat: If your debt exceeds a week (sorry, new moms) or you've pulled all-nighters, a binge or two won't be enough to offset the effects of sleeplessness, such as weight gain or a weakened immune system. Once life becomes more manageable, Dr. Winter advises, go to bed when you're tired and try to keep regular wake-up times for as long as you were deprived in order to undo the damage.

Next Page: The rule: toss expired meds [ pagebreak ]
The rule: Toss expired meds.
The new thinking: Save 'em; they might be A-OK.

"Many over-the-counter pills are effective past their expiration date," says Holly Phillips, MD, a New York City internist. And a 2012 study in the Archives of Internal Medicine showed that some prescription drugs could be good for up to 40 years past the expiration date.

So why the conservative sell-by dates? They tell you how long a drug's manufacturer can guarantee the product's stability, per FDA rules. The drug may stay potent beyond that time. And for some household staples, such as over-the-counter heartburn meds and painkillers, a lowered potency won't hurt you, says pharmacologist Joe Graedon, co-founder of the People's Pharmacy.

To be totally safe, throw these staples out a year after the expiration date. And strictly heed the dates on "any medicine meant to treat a life-threatening situation, such as insulin and epinephrine," Graedon says, or drugs that go inside the nose and mouth, such as nasal spray or an inhaler—they can grow bacteria over time. And if you don't want to get pregnant, don't chance old birth control pills.

The rule: Never use the ER as your doctor.
The new thinking: Why wait to see your MD?

If you have an after-hours illness—hacking cough with fever, crippling UTI pain—it is perfectly OK to go to an emergency room. When you suddenly feel miserable, it's wise to get checked out ASAP; "better safe than sorry" is one rule that still applies.

4 Rules You Should Stick To
Hate to break it to you, but some health guidelines are set in stone.

Don't leave the house without sunscreen.
If you plan to be outdoors, safeguard your skin with a broad- spectrum SPF 30 (or higher) sunscreen.

Finish the whole course of antibiotics.
Not taking every last pill increases the risk that the infection may rebound even stronger.

Don't smoke—period.
Even an occasional cigarette can set you up for the health issues regular smokers have, from saggy skin to cancer.

Brush and floss daily.
Ideally, you'd pick up the toothbrush twice a day and the floss at least once.