How Daydreaming Helps Your Mind Focus

Letting your mind wander may actually help your concentration, suggests new research from Cornell University.  

Here’s why scientists think that: In a study, participants matched photos of celebrities more quickly and accurately than they did for pictures of anonymous people they didn’t recognize. 

The Deadly Cancer That Grows for Two Decades

This news could leave you gasping: Lung cancer—which kills more people than any other cancer—can develop slowly for 20 years before it becomes aggressive enough to detect, finds new research from University College London.

Scientists studied 25 regions of seven lung tumors surgically removed from patients. They found that certain genetic mutations occur early in a tumor’s development, probably as a result of carcinogen exposure, especially in smokers and ex-smokers. Later—likely years later—a DNA-editing protein called APOBEC mutates DNA within the tumor, and that’s when the cancer really starts to progress, says study author Elza De Bruin, Ph.D.

How to Work Your Abs with a Basketball

When it comes to working your abs, a basketball probably isn't the first tool that comes to mind. But BJ Gaddour, C.S.C.S., CEO of Men's Health StreamFIT, came up with a fun—but tough—way to add it to your core routine.

The move: Dribbling a basketball while holding the top of a pushup position.

It's hard for two reasons, he says. First, you have to hold the position with only one arm.

5 Reasons She Hates Oral Sex

Can't break her BJ embargo? While some women just aren't interested in fellatio, your partner may be fine with it—but you could be killing her desire to go down below. Here are five things you do that turn her off to oral sex.

1. You get handsy. “When a guy pushes his partner’s head down during [oral sex], that’s the biggest complaint I hear from women,” says Ava Cadell, a doctor of human sexuality and author of NeuroLoveology. Despite what you see in porn, a lot of women aren’t cool with you working her head like it’s a football and you’re running a play-action fake. Instead, “Give her compliments on how good she is at giving oral and how beautiful she looks while she is doing it,” Cadell advises.

What Marijuana Might Do to Your Brain

The stoner character may be more than stereotype: Smoking pot may actually make you lazy. Occasional marijuana use can affect your motivation, according to a recent study from Harvard Medical School.

Out of 40 college students, the half who smoked pot once or twice a week for a few months showed more changes in the brain areas regulating emotion, mental illness, and motivation than the drug-free undergrads. “Your motivation levels determine whether or not you get out of bed in the morning,” says study coauthor Anne Blood, Ph.D. "And we're seeing some pretty convincing changes in these regions.”

The Easiest Way to Keep Off Weight

Good news for your waistline: A shot of sunshine in the morning may lower your body mass index (BMI), according to a new study from Northwestern University's Feinberg School of Medicine.

Regardless of an individual's physical activity level, diet, sleep, or age, people who had most of their daily exposure to natural light between 8 a.m. and noon had significantly lower BMIs than those who got most of their exposure later in the day.

The reason: Natural light provides a boost to your circadian rhythms—or your body's internal clock—which is known to regulate your metabolism, hunger, and energy levels, says co-lead author, Giovanni Santostasi, Ph.D. In fact, previous studies have found that constant exposure to bright light later in the afternoon or at night can throw off your circadian clock and increase your risk of obesity.

The Worst Work Hours for Your Health

Bad news if you burn the midnight oil: People who regularly work night shifts are twice as likely to have diabetes, finds new research from the University of Pittsburgh.

And the risk remains even after they've retired and returned to a normal sleeping schedule.

How come? Previous research shows that messing with your biological clock and limiting sleep can lead to decreased resting metabolic rates and increased blood glucose concentrations, which set the stage for diabetes and other diseases, says study author Timothy Monk, Ph.D.

Are You Overhydrated?

You've heard it since you were a kid, from your parents to your gym teacher: Drink two liters (or eight glasses) of water every day. Lately, though, researchers have been questioning the tried-and-true water rule, and in fact, believe even health-minded individuals could be drinking too much H2O.

“There’s no scientific method behind those numbers,” says exercise physiologist Stacy Sims, Ph.D., a hydration researcher at Stanford University. “And the recommendation doesn’t take into account gender, environment, altitude, fitness level—factors that could affect fluid intake needs.”

In fact, there’s a lot of marketing behind popular hydration recommendations, Sims says—with potentially dangerous consequences. “Drinking too much fluid can lead to hyponatremia, which is when sodium in blood becomes too diluted,” Sims says.