Watch Your Girth

May 13, 2008

Waist

By TARA PARKER-POPE

IT’S time to step off the scale and get out the tape measure.

The size of your waist can tell you far more about the state of your health than the number on a bathroom scale. Studies have linked larger waist sizes to higher risk for heart attack, cancer, diabetes, dementia and even incontinence.

Last month, Harvard Medical School researchers reported on a study of 44,000 nurses that showed even normal-weight women face twice the risk of premature death from heart disease or cancer if they are thick around the middle. Other studies have shown similar risks for men.

The notion of waist size as a barometer of health has been around for years, but the vast majority of doctors still put patients on a scale and calculate their body mass index, which measures weight relative to height.

But many studies of both men and women now suggest that it is not how much you weigh but where you carry your weight that matters most to your health.

In March, an analysis in The Journal of Clinical Epidemiology showed that body mass index is the “poorest” indicator of cardiovascular health, and that waist size is a much better way to determine, for both sexes, who is at a higher risk for hypertension, diabetes and elevated cholesterol.

Studies suggest that health risks begin to increase when a woman’s waist reaches 31.5 inches and her risk jumps substantially once her waist expands to 35 inches or more. For men, risk starts to climb at 37 inches, but it becomes a bigger worry once their waists reach or exceed 40 inches.

However, those numbers are based on averages and are not always useful for very tall or short people, children or certain ethnic groups. Among the Japanese, for instance, health risks start to increase for men with a waist size above 33.5 inches, but for Japanese women, risk does not increase until their waists expand to 35.5 inches.

Last month, The International Journal of Obesity suggested that, particularly for young people, the waist-to-height ratio might be a better indicator of overall health risks. Put simply, your waist should be less than half your height.

But a thick waist does not always correspond with poor health. One extreme example is the Japanese sumo wrestler who despite his massive size still might have the cardiovascular health of a slimmer athlete. Sumo wrestlers typically store fat just beneath their skin, where it doesn’t cause harm, rather than deeper in their abdomen.

Still, for most people, waist size is important. “We’ve known for a long time that people who tend to deposit fat inside their abdomen are the ones who have the highest risk for diabetes and heart attacks,” said Dr. Arya M. Sharma, chairman of obesity research and management at the University of Alberta. “For most people who are not sumo wrestlers, it’s actually quite a good indicator.”

Having a large waist means you are more likely to have fat around your heart, liver and even ordinary muscles, and it signals that you should be screened for other health problems, like insulin resistance and high cholesterol — particularly high triglycerides.

Losing even a little weight can have a big effect. In a small study, 20 severely obese patients who were put on a very low-calorie diet lost an average of 20 percent of their body weight. That translated into only a 19 percent drop in body mass index, but waist size fell 23 percent. Inside the body, the effect was even greater. Using imaging technology, researchers found that the layer of fat around the heart shrank by an average of 32 percent, according to a report this month in the medical journal Obesity.

Stress hormones have also been linked to abdominal fat. In one study, researchers used blood and saliva tests to measure the stress response of 67 women, ages 18 to 25, who were subjected to speech and math tasks. Women who experienced the most stress during the tasks were more likely to have a thicker waist than the women who were not stressed, according to the March report in The International Journal of Obesity.

Doctors say that while diet and exercise can help shrink your waist, most people find it tough to succeed.

If you have a large waist, your first goal should be to stop gaining weight, Dr. Sharma said. Exercise and improving the quality of the food you eat will lower your risk for heart and other problems, even if you never lose pounds or inches.

“You might want to focus on being as healthy as you can and not obsess about your weight,” Dr. Sharma said. “Obesity management is not about treating numbers on a scale. It’s about improving people’s health.”

http://www.nytimes.com/2008/05/13/health/13waist.html

Bolt Is Freaky Fast, But Nowhere Near Human Limits

By Alexis Madrigal

As astonishing as Usain Bolt's record-breaking 100-meter sprint was, his time of 9.69 seconds is nowhere near what biostatisticians predict is the natural limit for the human body.

But because he broke the mathematical model that had fit 100-meter record data for almost a century, Bolt's incredible performance could reset how fast researchers believe humans ultimately can run.

"This trend seems to defy simple curve fitting," wrote Tatsuo Tabata, director of the Institute for Data Evaluation and Analysis in Japan.

Statisticians have used a lower limit for 100-meter times of about 9.45 seconds, according to Tabata and other researchers. The exponential curve seen above -- which is drawn from an equation calculated to fit the world record data -- had been quite successful at predicting the steady progress of faster and faster 100-meter times. But Bolt's recent string of world records was clearly not an expected event: The model didn't predict a 9.69 until almost 2030.

Though no statistician we spoke with had recalculated their numbers, the new world record is likely to rejigger the equations they use to calculate the maximum human speed.

"With this new data, [the predicted fastest 100-meter time] would probably go down a little bit," said Reza Noubary, a mathematician at Bloomsburg University of Pennsylvania and author of a textbook on statistics and sports. He had previously calculated an "ultimate record" of 9.44 seconds for the 100 meter.

Mathematicians like Noubary don't use the body's physiology to assess human physical limits. They were merely working with data that suggested that human speed increases were decelerating and would eventually stop completely. Indeed, in some events, like the long jump, the pace of record-setting has slowed nearly to a stop. That record has only been broken twice since 1968.

But it could just be that mathematicians have been modeling the pace of progress wrong all along.

Several years ago, Jonas Mureika, a physicist at Loyola Marymount University in Los Angeles, developed a model using techniques drawn from seismology that predicted a Bolt-like time by 2009. But, he didn't believe his own numbers and decided not to publish the work.

"The record then was about 9.79 and [the model] predicted these crazy times, that by 2009 it'd be down in the high 9.6s," Mureika said. "I thought that's crazy, it's not going to progress that fast. Every day that I think about that, I kick myself. That's my penitence for doubting the numbers."

Despite the success of Mureika's model, Peter Weyand, a physiologist at Southern Methodist University in Dallas who focuses on the biomechanics of running, said that mathematical models could never predict how fast humans might eventually run.

"Predicting it is fine for the sake of kicks, but it's not a scientifically valid approach," Weyand said. "You have to assume that everything that has happened in the past will continue in the future."

He suggested that it's impossible for mathematicians to predict the magnitude of the freakiness of athletic talent at the extreme margins of humanity. Bolt, it turns out, is a perfect example.

Weyand, who has conducted research on the body types of the top 45 100-meter sprinters in the last 15 years, said that almost all elite runners conform to the body norms for their race length, except for the most-recent Olympic champion.

"Bolt is an outlier. He's enormous," Weyand said. "Typically when you get someone that big, they can't start."

That's because muscle speed in animals is generally tied to their size. For example, rodents, being much smaller than elephants, can move their muscles much faster. The same holds true for human beings. Sprinters are short and have more fast-twitch muscle fibers, allowing them to accelerate quickly, but compromising their ability to run longer distances. Four hundred-meter runners, almost always taller, have the reverse composition of muscle fibers.

Bolt, though, combines the mechanical advantages of taller men's bodies with the fast-twitch fibers of smaller men.

"We don't really know what the best form is and maybe Bolt is redefining that and showing us we missed something," said biomechanicist John Hutchinson of the Royal Veterinary College at the University of London, who studies how animals move.

Hutchinson also agreed with Weyand that the human speed limit will remain impossible to predict with any confidence.

For him, it's the International Olympic Committee and other regulatory authorities that will determine how fast athletes will be able to run by limiting the amount of advanced biotechnologies sprinters can use.

"The limits will be largely set by the rules of the IOC," Hutchinson said. "It's kind of an arms race with the regulators of the sport and the people trying to push the technology to the limits. At some point here there must be a détente where technology can't push us any further and the rules will restrict it."

With techniques for gene therapy likely to become available at some point in the not-too-distant future, Weyand said that its use by athletes was "inevitable."

"You could see really freakish things and we probably will," he warned.

http://blog.wired.com/wiredscience/2008/08/bolt-is-freaky.html?npu=1&mbid=yhp

Beijing trumps Athens … and then some

By Martin Rogers, Yahoo! Sports Aug 24, 11:29 am Et

BEIJING - AUGUST 24: Firework…
Getty Images - Aug 24, 11:11 am EDT

Children play in the dancing w…
AP - Aug 22, 11:20 am EDT

BEIJING – It is the biggest buzz word in Olympic circles, and the promise of it can dramatically sway the bidding process for future Games.

Legacy.

These days, any hopeful city with Olympic aspirations must not only show its ability to provide venues and infrastructure of the highest standard, but also prove there will be a lasting positive effect on the local community.

The 2004 Olympics in Athens showed how to get it embarrassingly and disgracefully wrong. Over the past 16 days, Beijing has shown the world how to get it magnificently right.

Four years since the Athens Games, a Greek tragedy is taking place. Incredibly, 21 out of the 22 Olympic venues now lie abandoned and in various states of ruin.

Gypsy camps have sprung up in the shadow of stadiums where the world’s finest athletes once battled for gold. Graffiti is scrawled over the outer walls of many sites, and it has been reported in Greece that upward of $1 billion has been spent simply to maintain these ugly wrecks.

That is Athens’ legacy.

Sixteen days of glory, but at what price? The Olympics are now almost a dirty word in Athens, most regularly used by politicians who use the issue of decay as a powerful campaigning point.

There was an element of tokenism in awarding the Olympics to Athens in the first place, a symbolic gesture intended as a nod to Ancient Olympia.

The Games will never return there. They will not be allowed to, if for no other reason than that the level of public outrage at the grotesque waste of money on oversized venues with no future is extreme.

Beijing is not going to let that happen. For a start, the Chinese capital has several huge advantages over Athens.

“The reason why some countries have been challenged with economic downturns after hosting an Olympics is that hosting cities are often very small,” said Chen Jian, executive president of the Beijing Economy Research Association. “Their investments in infrastructure construction were excessive. Fluctuations arose in the economic growth when no new hotspot for investment occurred after the Olympics.”

Beijing is a city that deeply loves its sports, even more so now given the host nation’s extraordinary success over the past fortnight.

The Bird’s Nest will be used for major international events, concerts and domestic soccer matches.

The Water Cube aquatic center was built to a sensible size, and will mainly be used for international diving competitions and exhibitions. Diving’s popularity in China should ensure that it is often filled to near capacity.

The luminescent light show on the glowing exterior of the stadium will be turned off soon after the Games, but will be put back on whenever there is a major event taking place in Beijing.

Other sites such as Workers’ Stadium and Workers’ Gymnasium were already in place. The Olympic Park Tennis Center has been tabbed to host an ATP event next year.

Whereas the list of Athens’ failures goes on, so too does the depth of Beijing’s successes.

The Games have sparked economic growth, and experts predict a continued surge in tourism as many fans who traveled to the Olympics are expected to return for a second look.

Here, there is a legacy of pride, and a spectacular standard of responsible spending for future hosts to uphold.

Whether you agree with China’s foreign policies or political ideals, no one can deny this has been a truly superb Olympic Games.

Congratulations, Beijing.

Gael Monfils of France returns a shot to Pablo Cuevas of Uruguay at the U.S. Open tennis tournament in New York, Monday, Aug. 25, 2008

Gael Monfils of France returns a shot to Pablo Cuevas of Uruguay at the U.S. Open tennis tournament in New York, Monday, Aug. 25, 2008

Michael Phelps became the greatest Olympian of all time(part 2 ) as the first athlete to win 10 career gold medals as he continued his charge to Olym

US swimmers Michael Phelps (R), Ryan Lochte (C), Ricky Berens (L) celebrate after their team swam to victory during the men's 4 x 200m freestyle relay swimming final at the National Aquatics Center during the 2008 Beijing Olympic Games in Beijing on August 13, 2008. A US team led by superstar Michael Phelps broke the men's 4x200m freestyle relay world record with a time of 6min 58.56sec. The victory gave Phelps his fifth gold medal of the Beijing Games and the 11th Olympic gold of his career.
























































































































U.S. men's 4x200-meter freestyle relay team first swimmer Michael Phelps gets a congratulatory kiss from a spectator following an awarding ceremony in the National Aquatics Center at the Beijing 2008 Olympics in Beijing, Wednesday, Aug. 13, 2008. The U.S. team won the event with a world record








Photo via Getty Images