ORLANDO, Fla. - Warning to weekend warriors: Swim-bike-run triathlons pose at least twice the risk of sudden death as marathons do, the first study of these competitions has found.

The risk is mostly from heart problems during the swimming part. And while that risk is low — about 15 out of a million participants — it's not inconsequential, the study's author says.

Triathlons are soaring in popularity, especially as charity fundraisers. They are drawing many people who are not used to such demanding exercise. Each year, about 1,000 of these events are held and several hundred thousand Americans try one.

"It's something someone just signs up to do," often without a medical checkup to rule out heart problems, said Dr. Kevin Harris, a cardiologist at the Minneapolis Heart Institute at Abbott Northwestern Hospital. "They might prepare for a triathlon by swimming laps in their pool. That's a lot different than swimming in a lake or a river."

He led the study and presented results Saturday at an American College of Cardiology conference in Florida. The Minneapolis institute's foundation sponsored the work and tracks athlete-related sudden deaths in a national registry.

Marathon-related deaths made headlines in November 2007 when 28-year-old Ryan Shay died while competing in New York in the men's marathon Olympic trials. Statistics show that for every million participants in these 26.2-mile running races, there will be four to eight deaths.

The rate for triathletes is far higher — 15 out of a million, the new study shows. Almost all occurred during the swim portion, usually the first event.

"Anyone that jumps into freezing cold water knows the stress on the heart," said Dr. Lori Mosca, preventive cardiology chief at New York-Presbyterian Hospital and an American Heart Association spokeswoman. She had no role in the study but has competed in more than 100 triathlons, including the granddaddy — Hawaii's Ironman competition.

Cold water constricts blood vessels, making the heart work harder and aggravating any pre-existing problems. It also can trigger an irregular heartbeat. On top of this temperature shock is the stress of competition.

"It's quite frightening — there are hundreds of people thrashing around. You have to keep going or you're going to drown," Mosca said.

Swimmers can't easily signal for help or slow down to rest during swimming as they can in the biking or running parts of a triathlon, said Harris, who also has competed in these events. Rescuers may have trouble spotting someone in danger in a crowd of competitors in the lakes, rivers and oceans where these events typically are held, he added.

For the study, researchers used records on 922,810 triathletes competing in 2,846 USA Triathlon-sanctioned events between January 2006 and September 2008.

Of the 14 deaths identified, 13 occurred during swimming; the other was a bike crash. Autopsies on six of the victims showed that four had underlying heart problems. Two others had normal-looking hearts, but they may have suffered a fatal heart rhythm problem, Harris said.

A search of the Minneapolis registry and the Internet found four other triathlon-related deaths from 2006 through 2008 beyond those that occurred in the officially sanctioned events.

"While not a large risk, this is not an inconsequential number," Harris said.

Fundraising triathlons have enticed many runners to try to expand into areas like swimming, which they may not have learned to do very efficiently, to benefit particular charities, Mosca said.

"They're really recruiting people to do these events," she said. "It can be a recipe for disaster."

Doctors offer these tips to anyone considering a triathlon:

_Get a checkup to make sure you don't have hidden heart problems.
_Train adequately long before the event, including open-water swims — not just in pools.
_Acclimate yourself to the water temperature shortly before a race, and wear a wetsuit if it's too cold.
_Make sure the race has medical staff and defibrillators on site.

But all the power wasted while computers are sitting idle overnight adds up, and one study has finally tried to measure it. The tally: An estimated $2.8 billion wasted on excess energy costs each year in the U.S. alone.

On a CO2 basis, that's 20 million tons of carbon dioxide, about the amount produced by 4 million cars on the road.

The full report is available for download here (scroll down to "PC Energy Report US 2009").

But big numbers like that become almost meaningless in an era of trillion-dollar bailouts, so to put the wasted energy in perspective, the study provides the data in terms you can better understand: If you run a company with 1,000 PCs left on overnight, you can save about $28,000 a year if they are turned off after hours. That's not chump change.

Of course, it's also a fact that your PC will function better if you restart it regularly, and nightly shutdowns can help you avoid having to suddenly reboot in the middle of the day when you'd otherwise be productive. So even though this little laptop, by my math, eats up only about a quarter's worth of power overnight, maybe it's a smart idea -- and ultimately a time-saver, too -- to shut it down after hours after all.

All the Jacko fans are in Jacko heaven. Starting this spring, anyone who wants a piece of Michael Jackson can get one: his personal belongings are scheduled for auction in April, and then in July he'll start his 50-show run in London. You can buy his glove and wear it to the concert.

But, of course, along with all the excitement about Jackson's return are rumors. There's always a rumor with Michael. Chatter is swirling that the dude at his recent press conference announcing the upcoming concerts was NOT actually Jackson. His voice was too deep, his chin too fake (something "too fake" on Jacko?), his walk was not Michael's usual gait.

If you ask me, I think he's probably with Elvis on a Tahitian island being served drinks by Jim Morrison. And they're all reading about Amy Winehouse's space-alien love child in the latest issue of National Enquirer. For their amusement and yours, I offer up these other musicians who've been the subject of scams, hoaxes, and mysteries through the years. You can file them next to your Oliver Stone DVD collection. Or next to your Joaquin Phoenix rap albums.

If there's one thing that gets in the way of you being your healthiest, it's stress. For anyone who's found themselves standing in front of the freezer inhaling spoonfuls of Coffee Heath Bar Crunch ice cream (not my real name!) to avoid finishing a project, or waking up three times in the wee hours of the night in anticipation of a difficult conversation, here's some not-so-shocking news: Research shows that anxiety can make you sleep fewer hours, get sick more often, remember less, become more prone to long-term disease and—as if you needed reminding—eat more. No wonder up to 90 percent of doctor visits are for stress-related complaints, a fact that I suspect too many of you know firsthand (though you experience it as GI distress, back pain, a headache or other physical symptom).

In a recent Self.com poll, 85 percent of women said that worries interfere with their ability to catch zzz's, while 71 percent say they're more irritable due to stress. And given the recent headlines about the state of our economy, it's not surprising that 52 percent of women say they are under considerably more stress than they were six months ago. (What is your stress level?)

Grim, yes, but there IS hope. Just as our bodies are wired to react to stress, we're all also programmed to know how to wind down, whether it's by watching a funny movie, sitting in the sauna, sipping some chamomile tea (while dunking a cookie, of course!) or drinking a glass (or two) of wine with dinner. These activities switch on the brain's pleasure centers, blocking the production of the stress hormone cortisol and churning out happiness-inducing chemicals like serotonin instead.

When I feel a tightening in my back or neck coming on, I cope by doing things I love, like going for a long, slow run in the park with my dog. Try a few of these instant soothers, and watch your own stress go from ARGH! to Ahhh.

Turn up the tunes. Listening to music that has a steady (not frenetic) beat may cause brain waves to keep time and relax you, research from a music symposium at Stanford University in California reports. Load your iPod with a playlist of the songs that make you happiest.

Phone a friend. Pouring your heart out to pals can help you cope with bad feelings and brainstorm new ways to solve problems. And don't forget to return the favor: Lending an ear and offering support can make you feel needed and reduce anxiety. (Or drop them an e-card to say thanks!)

Break a sweat. Exercising for 30 minutes makes your body release chemicals that dull the physiological effects of stress response for up to a full day. But the effect only works when the activity is something you really want to do, so make sure you're psyched about channeling your energy in that cardiovascular direction.

Use a better bulb. Outfit your office lamp with an incandescent bulb, particularly if your cubicle is brightened by fluorescent lights. Incandescent and fluorescent lights work together to more closely mimic outside light. And it's sunshine (or the perception of it) that regulates the body's biorhythms. Not getting enough of it can affect hormone levels, suppressing the immune system and increasing the probability of mood swings, depression and sluggishness.

Pamper yourself. Whether you get a pedicure or splurge on a blowout, giving yourself special treatment reduces your blood pressure and gets your mind off what’s bothering you. Science supports this coping mechanism as well: A warm bath can activate neurons that increase serotonin, and a study from Bowling Green State University in Ohio found that a 15-minute massage can significantly cut anxiety levels. Not up for a splurge? Get the same effect from an at-home pedicure, manicure or blowout.

Dine by candlelight. The effect won't just make you look gorgeous. The dim setting actually signals your brain to release melatonin, the good-for-you sleep hormone which ensures a better night's rest. And catching enough zzz's helps keep your stress levels under control and your immune system humming. Can't sleep? See what your stress dreams are trying to tell you.

Snuggle with your sweetie. A simple 20-second kiss or hug increases endorphin levels, while having sex releases more calming hormones than any other form of sex play, researchers at the University of the West of Scotland at Paisley note.

Keep a journal. Jotting down your stressful thoughts can help you look at them more logically, potentially easing anxiety, mentally and physically. A study in the Journal of Health Psychology finds that a mere month of expressive writing can help reduce hypertension. Keep a pretty notebook handy at all times.

Anticipate something awesome. Or something tiny that makes you smile. The point is to look forward to something each day, whether it’s enjoying your morning java or counting down to an exotic vacation. Practicing this will keep your mind from focusing on what could go wrong that day.

Exhibit your exhilarating moments. Tape up pictures of three amazing days you’ve experienced, such as dancing at your wedding or crossing the finish line of a half-marathon. Honing in on the images for at least 10 seconds can lower muscle tension and stabilize your heartbeat.

Give someone props. Go on, pay a compliment to someone deserving. Research has shown that the more warm personal connections you make, the better your body is at jettisoning the effects of stress.

Stress-eater? Snack away the tension with these stress-busting foods.

The Las Vegas welcome sign is dimmed during a one hour call to action for climate change during World Wildlife Fund's Earth Hour 2009 Saturday, March 28, 2009 in Las Vegas. (AP Photo/Isaac Brekken)

SYDNEY (Reuters) - Lights went out at tourism landmarks and homes across the globe on Saturday for Earth Hour 2009, a global event designed to highlight the threat from climate change.

From the Sydney Opera House and Harbour Bridge to the Eiffel Tower in Paris and London's Houses of Parliament, lights were dimmed as part of a campaign to encourage people to cut energy use and curb greenhouse gas emissions from fossil fuels.

Organizers said the action showed millions of people wanted governments to work out a strong new U.N. deal to fight global warming by the end of 2009, even though the global economic crisis has raised worries about the costs.

"We have been dreaming of a new climate deal for a long time," Kim Carstensen, head of a global climate initiative at the conservation group WWF, said in a candle-lit bar in the German city of Bonn, which hosts U.N. climate talks between March 29 and April 8.

"Now we're no longer so alone with our dream. We're sharing it with all these people switching off their lights," he said as delegates and activists sipped bluish cocktails.

The U.N. Climate Panel says greenhouse gas emissions are warming the planet and will lead to more floods, droughts, heatwaves, rising sea levels and animal and plant extinctions.

World emissions have risen by about 70 percent since the 1970s. China has recently overtaken the United States as the top emitter, ahead of the European Union, Russia and India.

BILLION PEOPLE TAKE PART

The U.N. Climate Panel says rich nations will have to cut their emissions to a level between 25 and 40 percent below 1990 levels by 2020 to avoid the worst effects of warming. Developing nations will also have to slow the rise of their emissions by 2020, it says.

Australia first held Earth Hour in 2007 and it went global in 2008, attracting 50 million people, organizers say. WWF, which started the event, is hoping one billion people from nearly 90 countries will take part.

"The primary reason we do it is because we want people to think, even if it is for an hour, what they can do to lower their carbon footprint, and ideally take that beyond the hour," Earth Hour executive director Andy Ridley told reporters at Sydney's Bondi Beach.

In Asia, lights at landmarks in China, Singapore, Thailand and the Philippines were dimmed as people celebrated with candle-lit picnics and concerts.

Buildings in Singapore's business district went dark along with major landmarks such as the Singapore Flyer, a giant observation wheel.

Other global landmarks that switched off their lights included the Petronas Towers in Kuala Lumpur, the Reserve Bank in Mumbai, the dome of St Peter's Basilica in Rome, Egypt's Great Pyramids and the Acropolis in Athens.

(Reporting by Reuters bureau; Writing by Jon Boyle)