By GINA KOLATA
Published: April 10, 2008



Correction Appended

I have a confession to make. I get so competitive about heart rates when I am at the gym that my husband will not tell me his.
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“How was your workout?” I’ll ask when we get off of Spinning bikes or elliptical cross-trainers. He’ll reply that it was good, he worked at “80 percent.” But 80 percent of what? I want to know what he thinks his maximum is. But he won’t say.

Of course, I know it’s ridiculous to think that a higher maximum heart rate means that I’m a better athlete than my husband. He may have a slower heart rate, but he can beat me in cycling any day. And, after all, the goal in exercise is to get more blood to your muscles. The heart does that by beating faster and by pumping more blood with each beat. If your heart is more powerful, it does not have to beat as fast. “There is no association between maximum heart rate and exercise performance,” said Hirofumi Tanaka, the director of the Cardiovascular Aging Research Laboratory and an exercise physiologist at the University of Texas in Austin.

In fact, Dr. Tanaka said, when people start exercising regularly their maximum heart rate often goes down.

And I know that the whole heart-rate monitoring issue is contentious. Many athletes strap on those slender black bands around the chests. Then they try to keep their rate at some percentage of their maximum, 70 percent, say, or 80 percent, depending on their goals for the workout.

For some activities, like using an elliptical cross-trainer or riding most Spinning bikes at the gym, it can be difficult to gauge your effort without a heart-rate monitor. You can’t figure out speed or distance the way you can if you are swimming in a pool or running or cycling outside. Maybe it’s all that sweating, but it always feels as if you’re working hard even when your heart rate tells you that you could do a lot more.

But experts disagree on whether heart-rate monitoring makes sense.

Exercise physiologists tend to favor it. “You need to keep track of exercise intensity” in order to meet performance goals or to improve, Dr. Tanaka said. He does not rely on standard formulas for finding maximum heart rate, though, because they vary so much from person to person. Instead, he advises that people find their maximum “in a field setting.” He suggests going to a track and gradually increasing your speed until your heart rate stops climbing.

Some coaches, like the one who trains Dr. Richard Friedman, 51, a masters swimmer in New York, set their own heart-rate goals for athletes. And, that, said Dr. Friedman, a psychiatrist at Cornell, is a problem. Even though he is one of the fastest on his team, his coach insists that he should hit a heart rate of 150 when he does, say, repeats of 50 meters freestyle in 60 seconds.

“I can never get my heart rate up to his target no matter how hard or fast I swim,” Dr. Friedman said.

Others, like Kevin Hanson, coach to Brian Sell, who just made the United States Olympic men’s marathon team, advise against monitoring your heart rate.

The classic formula for determining your maximum rate, 220 minus your age, is notoriously inaccurate, he said. And glancing at your heart-rate monitor all the time can hinder your training, he cautioned.

“It ends up playing mind games with you,” Mr. Hanson said. “Let’s say you are out for a 10-mile run and you don’t feel tired. Then you look at your heart rate,” and it is so high you decide you must have overdone it. Suddenly, he said, you feel tired and slow down.

Everyone’s maximum heart rate declines, slowly and steadily, with the passing years. So if your heart rate is higher than expected, doesn’t that mean you are exercising like a younger person?

It depends. On the one hand are athletes like Lance Armstrong, known for having an unusually high maximum heart rate. And that, said Edward F. Coyle, an exercise physiologist who has studied Mr. Armstrong, was to his advantage because his heart also was extremely efficient. A high maximum heart rate, helps, “all other things being equal,” Dr. Coyle said. The problem, he noted, is that there are so many other factors in performance that rarely are all other things equal.

So if Dr. Friedman could get his heart rate to 150, wouldn’t he be faster?

Not necessarily. And the story of Rebecca Soni, a swimmer at the University of Southern California, helps explain why. Ms. Soni, who has the second fastest time for an American woman in the 200-meter breast stroke, had an irregular heart beat. At times when she exercised her heart would beat up to an astonishing 400 times a minute.

Instead of making her swim faster, though, her fast-beating heart made her go limp. In 2006, in order to continue competing, she underwent a procedure to destroy heart tissue that was causing her heart to beat so fast.

This suggests two things. First, a faster heart isn’t necessarily better. And, second, hearts can beat much faster than they ever actually beat when most of us exercise. Something slows our hearts down, probably for the good of our performance or survival.

A heart beating at its maximum possible rate may be inefficient, Dr. Tanaka explained. As the heart beats more quickly, there comes a point when there is too little time between beats for it to fill with blood. “For exercise capacity, heart rate is not the issue,” said William Haskell, an exercise physiologist at Stanford University. “The heart has got to be an efficient pump.”

It turns out that the heart rate is controlled by three factors. First is the heart’s own intrinsic rate, how fast it would beat if you cut all its nerves and removed it from the body. The heart’s own internal pacemaker would make it beat roughly 40 to 60 beats per minute more slowly than its maximum rate. And, Dr. Tanaka said, the heart’s intrinsic rate declines with age parallel to the maximum heart rate’s decline with age. No one knows why.

The other factors controlling heart rate are the sympathetic nerves, which speed it up, and those that slow it down, the parasympathetic nerves.

When you start to exercise, said Patrick O’Connor, an exercise physiologist at the University of Georgia, the first thing that happens is that the parasympathetic nerves become less active. That makes your heart beat faster. As the intensity of your effort increases, the sympathetic nerves come into play, speeding the heart still more.

But there are complications. Anxiety, for example.

“We had people on treadmills who were getting ready to start,” Dr. O’Connor said. “Their heart rates were 160 or 170.” They weren’t exercising, just nervous, he explained. And when they started to run on the treadmill, their heart rates went down.

There’s a lesson here, of course, for runners who use heart-rate monitors during a race. Be careful about interpreting those numbers.

Then there are the differences among sports. Swimmers, for example, have lower heart rates when they swim than runners when they run. The reason, Dr. O’Connor explained, is that during running, your heart has to push blood against gravity to bring it to your head. During swimming, your heart does not have to exert that extra force.

Maybe Dr. Friedman should tell his coach.

As for my husband, he knows that my fixation on whose heart rate is higher is ridiculous. Still, I wish I knew what he thinks his maximum is and how he knows it.

MIKE PERRY, a 31-year-old rower, trained by himself in Ann Arbor, Mich., for six years while his wife attended medical school. Now he is a member of the United States rowing team and hopes to be selected in a couple of months to compete in the Summer Olympic Games.

These days, he works with a coach and a team, and for the first time he is also going to a gym twice a week and lifting free weights for his upper and lower body, and doing a lot of core exercises, he said. His coach insists upon it. Mr. Perry, though, said he cannot tell whether weight lifting is helping his performance.

His 29-year-old teammate, Mark Flickinger, thinks weight lifting has helped him. He said it is difficult to distinguish between the effects of training by rowing on the water and weight lifting at the gym.

Full Story: Here

It can happen for no reason, it seems, taking you completely by surprise. And it can be excruciating. Suddenly, a muscle contracts violently, as if it had been prodded with a jolt of electricity. And it remains balled in a tight knot as painful second after painful second drags on.

A seized calf muscle or a hamstring can be frightening. Swimmers fear they will drown. Cyclists nearly fall off their bikes. Runners drop to the ground, grimacing, gritting their teeth.


Full Story: Here

66 percent of US adults overweight. 75% by 2015

http://www.chinaview.cn


LOS ANGELES, July 20 (Xinhua) -- With the obesity level in the United States continuing to climb, 75 percent of American adults will be overweight and 41 percent of them will be obese by the year 2015, a new study predicts.

In the study, researchers at the Johns Hopkins Bloomberg School of Public Health found that the prevalence of obesity and overweight in the U.S. has increased at a median rate of 0.3 to 0.8 percentage points per year during the past 30 years across a wide variety of socioeconomic groups.

As a whole, the U.S obesity prevalence escalated from 13 percent in the 1960s to 32 percent in 2004, according to the study.



The research team noted that there was a disproportionate increase in obesity levels amongst minorities and low socioeconomic groups, including non-Hispanic black women and children, Mexican-American women and children, white women and black men of low socioeconomic status, Pacific Islanders, and Native Americans.

"The obesity rate in the United States has increased at an alarming rate over the past three decades," said Youfa Wang, assistant professor in the Department of International Health at the Johns Hopkins Bloomberg School of Public Health.

"We set out to estimate the average annual increase in prevalence as well as the variation between population groups to predict the future situation regarding obesity and overweight among U.S. adults and children," he said.

Wang also cautioned "Obesity is a public health crisis. If the rate of obesity and overweight continues at this pace, by 2015,75 percent of adults and nearly 24 percent of U.S. children and adolescents will be overweight or obese."

They also found that in 2003 and 2004, two-thirds (66 percent) of the U.S. adults were overweight or obese. Women between the ages of 20 to 34, have the fastest rate of increase to be overweight or obese. Eighty percent of black women aged 40 years or over are overweight with 50 percent being classified as obese. Although Asians have the lowest obesity prevalence when compared to other ethnic groups; U.S.-born Asians are four times more likely to be obese than Asian nationals.

The study was published in the latest issue of the journal Epidemiologic Reviews.

Full story here


By Terri Coles



TORONTO (Reuters) - Consumers who are keen to know if the food they're buying has been grown without synthetic pesticides and fertilizers have more information at their fingertips than they may realize, although it may not be official.

Food certified by the United States Department of Agriculture (USDA) as grown without synthetic pesticides or fertilizers carries the "USDA Organic" label. Some producers, however, choose to indicate that organic growing practices are being used but the requirements for organic certification haven't yet been met. Others have no intention of gaining USDA Organic certification, but still want to label their products in a way that highlights the natural farming methods used to grow them.

"There are a variety of terms that are popular as an alternative to organic, but they cannot mean organic," said Kathy Means of the Produce Marketing Association. Products cannot be labeled as organic unless they are certified through the USDA. To receive certification, crops must be grown without synthetic fertilizers and pesticides for three years.

The Poisoning Of America for Profit!
By Skip Chase
CrossFit Mt Vernon




Yummy, aren't they? or are they? What do these products have in common? The box on the left is a 'treat' for our toddlers...the other products are found in almost every refrigerator in this country.

Ok....here I go....Hi, my name is Skip and I am a sugarholic!

I've written that statement on other posts on this blog. I am going to keep saying it. AMERICA IS ADDICTED TO SUGAR!!!!

I am going to keep saying it and continue to attempt to convince you to convince yourself that you are addicted to sugar, and you must change!!

Why are we addicted to sugar? How did we become addicted to sugar?

Article Source: here!

One of the great unanswered questions in physiology is why muscles get tired. The experience is universal, common to creatures that have muscles, but the answer has been elusive until now.

Scientists at Columbia say they have not only come up with an answer, but have also devised, for mice, an experimental drug that can revive the animals and let them keep running long after they would normally flop down in exhaustion.

Read the entire article here!