Ever wonder why the person next to you seems more fit despite the fact that you both do the same workout? A new study indicates that not all exercise works for every body type. If you're not faster, more fit, more lean, or...you may need to change the type of exercise you do.

Phys Ed

Exploring Why Some People Get Fitter Than Others

By Gretchen Reynolds

April 29, 2015 5:31 am

 

Anyone in a running group or gym class has likely noticed that some of the participants annoyingly become much fitter than others. But exactly why some people’s bodies respond well to working out and others do not puzzles scientists.

Studies indicate, unsurprisingly, that genetics must be involved, since a particularly high or low response to exercise tends to run in families. But less has been known about which genes might be involved, and how those genes actually increase or blunt the body’s response.

Now a new study in rats adds to a growing body of data about how and why bodies respond so differently to exercise. In the study, rats with a particular set of genes responded robustly to exercise, becoming much more fit after a few weeks of running, while rats born with other genes gained little cardiovascular benefit from the same exercise program, apparently because their heart muscles didn’t react as expected.

The results raise questions about whether people who remain stubbornly unfit, no matter how diligently they work out, might want to rethink their exercise routines.

Anyone who closely examines the results of exercise-related experiments will notice that some participants get more physical bang from exercise than others. The range of response can be startlingly broad.

In a telling study published in March, for instance, 95 older, overweight men and women began five months of endurance or weight training. By the end of that time, the volunteers were, on average, 8 percent stronger or more aerobically fit (depending on which program they had followed). But 13 percent of those in the endurance group had lost aerobic capacity, and 30 percent of those in the strength-training group were weaker.

For the new rodent study, which was published this month in The Journal of the American College of Cardiology, scientists from the University of Michigan in Ann Arbor and the Norwegian University of Science and Technology in Trondheim created two strains of rats that would or would not respond well to working out.

To do so, they first had rats run for several weeks and noted how much distance the animals added before tiring during that time, meaning how well they were adapting to the workouts.

The males that added the most mileage were bred with the females who responded likewise, and the animals that added the fewest miles to their runs were also mated to one another.

After seven generations, the scientists had rats that should have been high or low responders to exercise.

And the first part of the new experiment proved that supposition to be true. The two types of rats were set on teensy treadmills with workouts that were identical in speed and intensity. The animals completed the same training program for two months.

By the end, the rats bred to respond well to running had increased the distance that they could run before tiring by about 40 percent.

The other rats were much more resistant to training, generally losing about 2 percent of their endurance during the training.

Next the scientists examined the animals’ hearts, since differences in cardiovascular responses to exercise could be expected to originate there. Normally, the left ventricle of the heart in animals and people becomes larger and able to contract more forcefully after a period of endurance training.

So it was among the high-responding rats. Cells from their left ventricles showed structural changes associated with growth and strength. They were developing athletes’ hearts.

Not so the other rats. Cells from their left ventricles looked like those from animals that hadn’t run. There were almost no physiological adaptations.

This cellular intractability likely explains why the animals lost fitness while training, says Ulrik Wisloff, a professor at the Norwegian University of Science and Technology who led the new study. 

If hearts don’t adapt to the demands of exercise, then workouts will sap bodies, not strengthen them.

But perhaps the most fascinating aspect of the new study involved the scientists’ determination of the gene activity driving these adaptations. When they carefully assessed gene expression in the animals’ heart cells, they found more than 360 genes that were operating differently in the two groups of animals. Many of these genes are known to affect cell growth.

In effect, these genes direct processes that should increase the size and strength of the heart. And they were not working as effectively in the animals bred to be resistant to exercise.

Humans have these same genes in our heart cells, Dr. Wisloff said, although it is impossible at this point to know if our genes respond in precisely the same way during exercise as the genes of the rats did, Dr. Wisloff said.

He also pointed out that the interplay of genes and exercise is extremely complex, and scientists are only in the earliest stages of understanding the effects of heredity, environment, nutrition and even psychology in affecting different people’s responses to exercise.

But the potential lesson of the new study would seem to be, he said, that we should closely monitor our body’s response to exercise. If after months of training, someone is not able to run any farther than he or she could before, maybe it is time to change the intensity or frequency of the workouts or try something else, like weight training. The genes that control the body’s responses to that activity are likely to be very different than those involved in responses to aerobic exercise, Dr. Wisloff said.

As human beings, our good physical health is intrinsically tied to our emotional well-being. If we could be most often happy, we'd simply feel better. Now a new study demonstrates that such happiness can spread - through the smell of sweat.

From Medical News Today -

Happiness can be spread through the smell of sweat, study finds

Last updated: Saturday 18 April 2015 at 12am PST

 

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Pharrell Williams should probably watch out - the "Happy" hitmaker might get an influx of fans trying to sniff him if the results of this latest study are anything to go by. Researchers found we can detect happiness in other people's sweat. What is more - this happiness may be contagious.

 

The researchers say their findings indicate the state of happiness can be transferred to others through the smell of sweat.

 

Published in the journal Psychological Science, the study found we produce chemical compounds, or"chemosignals," in our sweat when we experience happiness, which others can detect when they smell us.

These chemosignals trigger a "contagion of the emotional state," according to senior study author Gün Semin, of Utrecht University in the Netherlands. "This suggests that somebody who is happy will infuse others in their vicinity with happiness. In a way, happiness sweat is somewhat like smiling - it is infectious."
 
According to the researchers, past studies have indicated that chemical compounds in sweat can give off negative emotions that are detectable by others. They note, however, that few studies have looked at whether this is the case for positive emotions.

To reach their findings, Semin and colleagues enrolled 12 men to their study, all of whom were nonsmokers, free of any psychological disorders, and did not take any medications.

The men were asked to take part in an experiment that involved watching a video clip intended to produce one of three emotions: fear, happiness or a neutral emotion. In addition, the men were asked to view a number of Chinese symbols and rate how pleasant or unpleasant they felt each one was. This task was designed to measure their "implicit emotion," according to the team.

Prior to watching the video clip, the men rinsed and dried their armpits and attached absorbent pads to them, which they wore during each task. These pads were removed and stored in vials once the tasks were completed.

Throughout the duration of the study, the men were asked to refrain from consuming alcohol, smelly food and from engaging in exercise and sexual activity.

From an initial analysis, the team determined that the video clips succeeded in influencing the emotional states of the men - men who viewed the "fear" video clip experienced negative emotions, for example.

Findings shown both positive and negative emotions can be transferred through odors

Next, the researchers recruited 36 women to the study, all of whom were free of psychological disorders, respiratory diseases and any other illnesses.

In a double-blind experiment, the women were asked to smell a sweat sample of each type of emotion the men experienced - fear, happiness or neutral - while the researchers measured their facial expressions to determine the emotions they felt as they smelled each sample.

The researchers explain that they specifically asked women to take part in this task because they have a better sense of smell than men and a greater sensitivity to emotional signals.

The team found that when the women were exposed to the "fear sweat," they demonstrated increased activity in the medial frontalis muscle of the face - an activity associated with fear expressions.

In addition, the researchers found that women who smelled the "happy sweat" showed facial muscle activity associated with a Duchenne smile - activity linked to happy expressions. What is more, in perceptual-processing tasks, the team found women exposed to happy sweat showed a perceptual-processing style commonly associated with happiness.
 
When the women completed the Chinese symbol task after smelling the sweat samples, however, the team found the samples had no effect on their implicit emotional states.

Commenting on the findings, the researchers say:

"We observed that exposure to body odor collected from senders of chemosignals in a happy state induced a facial expression and perceptual-processing style indicative of happiness in the receivers of those signals. Our findings suggest that not only negative affect but also a positive state (happiness) can be transferred by means of odors."

Semin says the odor industry may benefit from their findings, noting that the fact happiness can be transferred to others chemically may have "potential commercial applications."

In August 2014, Medical News Today reported on a study by researchers from University College London in the UK, in which they created an equation to calculate people's happiness based on their rewards and expectations.

Written by Honor Whiteman

While many think too often of heart disease as a middle-aged male condition, studies indicate young women are just as much at risk. If you're over-weight, smoke, have diabetes, prone to stress, don't get enough sleep, and seldom exercise, heart disease doesn't really care which sex you are.

Personal Health

Young Women’s Hearts at Risk

By Jane E. Brody

April 13, 2015 5:45 am

 

Attention, American women, especially young women: Have you got the heart to save yours?

Although long thought of as a man’s disease, heart disease afflicts as many women, though women tend to develop and die from it about 10 years later. And while coronary mortality rates have declined over all, there are signs that the disease, its precursors and its potentially fatal consequences are increasing among young women.

A 2007 study in The Journal of the American College of Cardiology referred to the rise in cardiovascular risk factors among young women as “the leading edge of a brewing storm.”

While so many women worry about cancer, only slightly more than half realize that heart disease is their No. 1 killer, according to the Centers for Disease Control and Prevention. More women in the United States die from cardiovascular causes — heart disease and stroke — than from all forms of cancer combined.

Numerous campaigns by the American Heart Association and other organizations have raised awareness among women of their mostly self-inflicted risks and of symptoms that are typically far more subtle in women than in men.

“Even if they believe they’re having a heart attack, 36 percent don’t call 911,” said Dr. Holly S. Andersen, director of education and outreach at the Perelman Heart Institute at Weill Cornell Medical College, citing the latest heart association national survey. “Women are more likely to wait when they have symptoms and, when they get to the hospital, say that they have indigestion, not chest pain — a big mistake.”

Rather than crushing chest pain, women in the throes of a heart attack more often experience discomfort in the neck, jaw, shoulder, upper back or abdomen, dizziness, nausea, right arm pain, shortness of breath, and sweating or unusual fatigue. Almost two-thirds of women who die suddenly of a heart attack had no prior symptoms.

Doctors too often fail to take a woman’s risk seriously and treat it aggressively, or to provide adequate recommendations for prevention, Dr. Andersen and other experts say. “This is especially true for young women,” she said. Yet, she added, “among women between the ages of 29 and 45, it looks like the incidence of heart disease is rising.”

There are ample reasons. Stress, for example, is a known, though not often cited, risk factor, “and the youngest women in this country are more stressed than ever,” she said. “They’re always ‘on’ and self-comparing.”

Smoking — marijuana as well as cigarettes — is a coronary risk. And while smoking has declined among older women, “young women are the ones still smoking,” Dr. Andersen said. Women on birth control pills who smoke are especially at risk.

Two other major risk factors, obesity and diabetes, are more rampant than ever, especially among Hispanic women born in the United States, half of whom develop diabetes by age 70.

“We’re good at treating heart disease, but we’re failing at prevention,” Dr. Andersen said. As Dr. Nanette K. Wenger, a professor emeritus at the Emory University School of Medicine, noted in 2010, the steady annual decline in heart disease deaths among women since 2000 resulted more from better care than from prevention.

“A particular unmet need is prevention at younger age, the subset of women less likely to undertake preventive behaviors,” she wrote. Yet decades ago, heart disease was found to originate in the teenage years or early 20s and gradually worsen unless preventive measures were undertaken.

When women with high levels of artery-damaging LDL cholesterol are prescribed statins, the treatment often provides “false reassurance” that the drugs “can compensate for poor dietary choices and a sedentary life,” Dr. Rita F. Redberg, a cardiologist at the University of California, San Francisco, and editor of JAMA Internal Medicine, wrote last year. In one study she cited, “statin users significantly increased their fat intake and calorie consumption, along with their B.M.I. (body mass index), in the last decade. Focusing on cholesterol levels can be distracting from the more beneficial focus on healthy lifestyle to reduce heart disease risk.”

A diet rich in fruits and vegetables, which contain natural antioxidants that statins don’t provide, is more important, Dr. Andersen said. “So is getting regular aerobic exercise, spending time with friends and getting a good night’s sleep — six to eight hours,” she said. “Chronic lack of sleep doubles the risk of heart disease.”

Coronary risk is also greater among women who carry extra weight around the abdomen — the so-called apple shape. Abdominal fat is metabolically active and can result in high blood pressure and diabetes, even if a woman is otherwise slender.

“One’s waistline is more important than B.M.I.,” Dr. Andersen said. “Skinny people with big waists are less likely to live long.”

Depression and lack of social support, more common among older women, are also often underappreciated risk factors. “Social isolation is detrimental,” she said. “Women who regularly spend time with close friends live longer and have less heart disease.”

A positive outlook on life — laughing a lot, having a sense of humor, being optimistic and seeing the glass as half full — is also protective, Dr. Andersen said, adding that “15 minutes of laughter is equivalent in preventive value to 30 minutes of aerobic exercise.”

Although “marital stress increases a woman’s risk of coronary heart disease,” having a compatible partner or a pet is beneficial, she said.

Several factors that women may experience early in life, especially two pregnancy-related conditions — pre-eclampsia and gestational diabetes — have been linked to a greater coronary risk years later. 

Additional risk factors now emerging for women include migraines with aura and inflammatory diseases like lupus and rheumatoid arthritis.

Two other conditions more prevalent among women cause symptoms that are often overlooked by them and their doctors as likely due to heart attack. Women are more prone to develop blockages in the small vessels that feed the heart, which can cause pressure or tightness in the chest rather than crushing pain, according to the National Heart, Lung and Blood Institute.

They are also far more susceptible to “broken heart syndrome” brought on by events like the sudden loss of a loved one, the loss of a job or money, divorce, a bad accident, a natural disaster, or even a surprise party. The resulting intense stress reaction of chest pain and shortness of breath, although usually temporary, can mimic a heart attack, though it rarely causes one.

Household cleaners can be a cause of health issues, particularly among children. A new study reported in MNT looks at exposure to bleach being behind an increase of infections in kids.

 From Medical News Today -

Could passive exposure to bleach increase infection rates in kids?

Last updated: Friday 3 April 2015 at 12am PST

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MNT featured Academic journal

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A team of European researchers has suggested that passive exposure to bleach in the home could increase the frequency of respiratory and other infections among school-age children. 

 

 

Bleach is widely used in homes, schools and other  public buildings across the world as a cleaning product.

 

 

The study, published in Occupational & Environmental Medicine, examined the effects of exposure to bleach in the home among children from schools in Finland, Spain and the Netherlands.

Previous studies have suggested the use of cleaning agents in the home may increase the risk of respiratory infections and wheezing during the first year of life, and airway inflammation at school age.

Bleach is a cleaning agent that is used widely across the world. According to the researchers, a cross-sectional study has previously reported that children at school age living in a house where bleach is used had an increased risk of recurrent bronchitis, although also received some protection against asthma and allergies.

For the new study, the researchers examined the impact of bleach use in the homes of 9,102 children aged 6-12 attending 19 schools in Utrecht, The Netherlands, 18 schools in Barcelona, Spain, and 17 schools located in Eastern and Central Finland.

The parents of participating children completed questionnaires detailing whether they used bleach to clean their homes once a week and the amount of times their children had developed the following infections over the course of the past 12 months:

• Bronchitis
• Flu
• Otitis
• Pneumonia
• Sinusitis
• Tonsillitis.

Parents had the choice of reporting infection frequency as "never," "once," "twice" or "more than three times."

Bleach use varied in the countries participating in the study. While 72% of respondents from Spain reported using bleach, only 7% of those from Finland did. Additionally, all of the Spanish schools involved with the study were cleaned with bleach whereas none of the Finnish schools were.

Effects reported in the study are a public health concern, authors state

After adjusting for other potentially influential factors such as passive smoking, household mold and the use of bleach to clean school premises, the researchers found that the number and frequency of infections were highest among children whose parents regularly used bleach in their homes.

The researchers noted statistically significant differences for flu, tonsillitis and any infection. Among children whose parents used bleach in the home, the risk of one episode of flu in the past 12 months was 20%. For recurrent tonsillitis, the risk was 35% higher, and for any infection it was 18% higher. The findings were the same in all three countries.

"Our results suggest that passive exposure to cleaning bleach at home is associated with an increased frequency of respiratory and related infections in school-age children," write the researchers.
 
A number of limitations to the study are identified by the authors. "Unfortunately, we did not have information on the use of other cleaning products and we cannot exclude the possibility that the observed results are due to the use of other irritants or to their combinations," they state.

Equally, only basic information was gathered for bleach use in the home, making it difficult for the authors to differentiate exposure levels between participating families.

As the study is observational, the authors cannot make any definitive conclusions about causation though they believe their findings support those from other studies suggesting a link between cleaning products and respiratory infections.

They suggest that further studies in this area should be conducted, including more detailed descriptions of bleach use and objective measurements of exposure and health outcomes in order to confirm their findings.

"Nevertheless, the high frequency of use of disinfecting cleaning products - caused by erroneous belief, reinforced by advertising, that our homes should be free of microbes - makes the modest effects reported in our study of public health concern," the authors conclude.

Previously, Medical News Today reported on a study in which researchers discovered over 30 new genes that predispose individuals to both asthma and allergies such as hay fever.

Written by James McIntosh