Yes, you're a busy guy: Places to go, people to see, pecs to pump. So when there aren't enough hours in the day to fit it all in, you borrow 60-odd minutes from your night. Make that a habit and you may eventually fool yourself into thinking that six hours' sleep is all you need to cruise through life.

BRRRING! You can't hit snooze on this alarm. Depriving yourself of sleep is self-inflicted corporal punishment. How serious can missing a few ZZZs be? So dangerous that simply staggering around like a Night of the Living Dead extra may be the least of your problems. Sleep restriction wears down your body and beats up your brain, leaving you slow, soft, and sick--even dead--years before your time.

But don't panic (that'll only keep you up tonight). Instead, study the following six eye-opening reasons why you need to spend more time with the Sandman, then apply these tips we've provided to make the sleep you're getting even more restful.

Sleepless Side Effect: HEART DISEASE
Mounting evidence suggests that sleeping too little may increase your risk of coronary heart disease. Average less than five hours of sleep a day, a study in the Archives of Internal Medicine warns, and your chance of suffering a heart attack--or dying from one--nearly doubles compared with guys who put in longer shifts between the sheets.

Sleep It Off: Diffuse that ticker time bomb the way James Bond would--by going undercover. Every extra minute you spend sleeping helps suppress your sympathetic nervous system, the part of the body that creates "fight or flight" hormones during stressful situations. "Hormonal disturbances can raise blood pressure, increase heart rate, and disrupt glucose metabolism--all major contributing factors to cardiovascular disease," explains Harvard Medical School's Sanjay Patel, M.D. "Sleep gives the heart time to relax in a low-stress state." Which explains why prolonging your bed time may just extend your lifeline.

"The people who live the longest--and are the healthiest--tend to sleep between seven and eight hours nightly," adds psychologist James Maas, Ph.D., a sleep expert at Cornell University. To determine the ideal amount of time you need to doze each night, Maas recommends hitting the hay 15 minutes earlier than normal for an entire week. If you still feel sluggish midday, keep adding 15 minutes to your nightly sleep routine every week until you finally feel rested and energized. Convinced you're getting enough sleep? Don't bet on it. University of Pennsylvania researchers found that even the most chronically sleep-deprived men report feeling "only slightly sleepy."

Sleepless Side Effect: WEIGHT GAIN
Those love handles you're sporting aren't solely from that Krispy Kreme habit. Exhaustion is a main ingredient in the recipe for jelly belly. "Sleep deprivation disrupts your metabolism, seriously sabotaging efforts to maintain an ideal weight," says Jana Klauer, M.D., an obesity researcher at NYC's St. Luke's-Roosevelt Hospital. Here's how it works: Fat cells produce a hormone called leptin, which tells the body how much potential energy it has stored. Since leptin production peaks at night, when you're asleep, sleep deprivation can throw levels of the hormone out of whack. The end result? Your body has no idea how much energy it has banked, so you end up storing fat instead of burning it.

Sleep It Off: The best way to trim the fat is to grab your 40 winks. So consider a full night's rest an integral part of any weight-loss regimen. Getting sufficient sleep will prevent lags in energy and help reduce carb cravings, notes Klauer. It'll also help build belly-busting muscle. "Sleep deprivation causes a drop in the production of human growth hormone," says Klauer. (This ensures the fat your body stores will make a beeline for your waistline.) "After a good workout, you get a lot more deep, slow-wave sleep, and it's this cell-repairing stage of sleep where up to 70% of daily growth-hormone secretion takes place in young men." Meaning, even if you're getting in your time at the gym, you still need to hit the sack to complete the biological process that makes muscles pop.

Sleepless Side Effect: POOR SEX DRIVE
Too little sleep may leave you soft in the head (that's right--your favorite head). "Sleep deprivation can increase your risk of erectile dysfunction," says Jon L. Pryor, a professor of urologic surgery at the University of Minnesota. That's because testosterone levels plummet when you don't get enough sleep, making it much tougher to get and sustain an erection. But you may be too tired to care, since low T also triggers a drop in men's desire for sex.

Sleep It Off: There's nothing like a rigorous romp in the sack to put you into a deep doze. Approximately 90 minutes after blissfully passing out, most men arrive in REM (rapid eye movement) sleep. That's the dream state in which erections naturally occur--up to five times a night, when you sleep long and well enough. And why should you care about sleep-induced arousals? Use it or lose it, friend. Think of each erection as a sexual chinup: Every time your penis rises, it becomes stronger and less vulnerable to impotence. So strong that you'll sport wood whether you're dreaming of Elisha Cuthbert or Dame Judi Dench.

Mom was right: If you burn that candle at both ends, you're bound to get sick. Lack of sheep-counting time is practically an invitation for infection. Case in point: In a recent report in the Journal of the American Medical Association, researchers found that when 11 sleep-deprived but otherwise healthy men were given a flu vaccine, they built up just half the level of antibodies--proteins produced by the immune system to battle foreign substances--as fully rested guys given the same shot.

Sleep It Off: Make your sleep more restful. A study published in Psychosomatic Medicine profiled 25 office workers who spent eight weeks in meditation training before receiving a flu shot. The meditators experienced a 53% rise in antibodies compared with their stressed-out colleagues. But you don't need to visit Camp Yoga to improve the healing power of your sleep. Instead of getting all Zen, fortify your existing bedtime ritual: When you go to bed, immediately lie down and clear your head of all thoughts. (Keep a tablet by your bed. If you can't stop thinking about something, write it down.) When your mind is finally relaxed, close your eyes and breathe deeply until you fall asleep. You'll awaken more rested--and resistant to illness--in the morning.

If you're shortchanging sleep in an attempt to get in exercise first thing in the morning, you may want to rethink your strategy. Add some jogging or a pounding in the weight room to your spine and you're much more likely to roll out of bed and herniate a disk than you are to break a personal record, Cornell's Maas says. Rising too soon also steals critical hours from time your body spends in stage-two sleep--the performance-enhancing phase of slumber that helps your brain perfect golf swings, tennis strokes, and three-point bombs from downtown.

Sleep It Off: Gradually adjust to vertical. Give your spine the morning to recalibrate before training. Just standing up and walking around for a couple of hours gets your body in good running, biking, or powerlifting form by noon. If you have to work out in the a.m., at least walk or jog a few minutes to help improve your flexibility and reduce your risk of injury. Better yet, go to bed earlier the night before so you can be awake a couple of hours before exercising. And say goodbye to those a.m. situps. Doing full-flexion exercises like situps in the early morning applies three times more stress to those discs than you'd experience a few hours after waking up. A better time to sweat: between 5 and 7 p.m. Sure, the gyms are more crowded then, but the post-work workout is when you're most alert and least accident-prone. Plus, you'll sleep better at night.

Sleepless Side Effect: MENTAL SLOWNESS
See that dimly lit bulb over your head? You know, the one where the great ideas are supposed to be coming from? Fatigue may be sapping its wattage. Sleep fosters the "offline" processing of data learned throughout the day into conscious knowledge. "Studies done on visual perception, motor skills, and creative tasks all show that if you don't sleep enough, learning just doesn't happen," says Sara Mednick, Ph.D., a neuroscientist at the Salk Institute. Think she's exaggerating? The National Sleep Foundation reports that sleep deprivation impairs mental performance almost as much as being drunk--only without the funny stories.

Sleep It Off: Sleep longer, wake up smarter. Some of the world's brightest flashes of artistic and scientific insight came to their authors following sleep. And for good reason: Sleep is essential for creativity. German research shows that math students are up to three times more likely to figure out a hidden problem-solving formula after getting eight hours of sleep than while sleep-deprived. And for those without a creative bone in their body, sleep is just as important. Research from the University of Chicago shows that sleep improves your ability to learn vocabulary and language skills, while a University of Pennsylvania study shows that getting at least a few hours of sleep after learning a crucial skill--or staying up to cram your head with information--can help your memory "gel" so you remember things more easily. (Bet you wish you'd known that in college.) Can't catch all your ZZZs overnight? "A 60-minute midday nap can also help improve learning," says Mednick.