Could This Newly Found Hormone Boost The Effect Of Exercise?

Could This Newly Found Hormone Boost The Effect Of Exercise?

By Katherine Harmon
(Click here for the original article)

Hormones aren’t just for sex—they help control everything from the times when we feel hungry to the timing of our heart beats. Dozens have been described, but there is now a new one on the scene. It might help explain some of the health benefits of exercise and point the way to preventing obesity and diabetes. The find was described online Wednesday in Nature (Scientific American is part of Nature Publishing Group).

Exercise has myriad benefits for the body and brain, but many of the triggers for these improvements have so far been somewhat of a mystery.

“There has been a feeling in the field that exercise ‘talks to’ various tissues in the body,” Bruce Spiegelman, a cell biologist at Dana-Farber Cancer Institute and co-author of the new study, said in a prepared statement. “But the question has been, how?”

Speigelman and his colleagues found that exercise—in both mice and humans—starts a cascade of signaling changes, including the production of a never-before-described hormone. They dubbed the new hormone irisin, as a nod to the Greek messenger goddess Iris for its ability to send information to surrounding body tissue.

And the messages irisin carries are not trivial—they seem to effect positive changes in the body. An increase in irisin helps turn white fat into the more beneficial and metabolically active brown fat, which burns more calories. It also seems to make the body more sensitive to glucose, an important capability for keeping diabetes at bay.

In the study, the researchers discovered that exercise increases the body’s production of a metabolism-regulating protein, which in turn stimulates expression of a protein that can produce the new hormone, found to reside in the outer membranes of muscle cells.

The effects of exercise on the hormone’s production seem to be long-lived. Even after 12 hours of rest, mice that had been on a three-week jogging regimen had 65 percent more irisin in their blood than unexercised mice. And people who had gotten 10 weeks of endurance exercise training had double the amount of irisin in their blood than those who had not.

But could this hormone, the scientists wondered, mimic some of the effects of exercise—without subjects having to hit the treadmill? To find out, they injected a batch of obese, pre-diabetic mice that had been fed a high-fat diet with just about as much of an irisin boost as they would get from a workout. After 10 days of injections, the irisin-boosted mice had shed a little weight and become more sensitive to glucose—all without exercise. And a later dissection showed that the hormone spike didn’t seem to have any negative biological effects.

“It is likely that irisin is responsible for at least some of the beneficial effects of exercise on the browning of adipose tissues and increase in energy expenditure,” Speigelman and his colleagues noted in their paper. This find might help explain some of the “afterburn” of extra calories after vigorous activity.

Even if the hormone proves safe for humans to take as a supplement, it won’t replace all the benefits of going to the gym. But it might help people fight obesity and remain more sensitive to glucose, thus fighting off diabetes.

“It’s exciting to find a natural substance connected to exercise that has such clear therapeutic potential,” Pontus Bostrom, a postdoctoral researcher at Dana Farber and co-author on the new paper, said in a prepared statement. The researchers are now also investigating possible effects of the exercise-based hormone on other diseases, including neurodegenerative conditions, and have licensed the finding to Ember Therapeutics (a company co-founded by Spiegelman) for drug development.

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Source: www.huffingtonpost.com

The Science Of Sex: 5 Must-Know Facts About Your Brain And Desire

The Science Of Sex: 5 Must-Know Facts About Your Brain And Desire
In recent years there has been a lot of talk about pheremones -- chemicals that have the ability to trigger a social (and potentially sexual) response from members of the same species. Some companies have even begun bottling these chemicals, urging consumers to use them as cologne and "enhance your sex life." According to Sukel, these bottled pheromones are little more than marketing. "As of now there's no good scientific study that shows that these sprays actually work," she said. "But there are plenty of people who use them and claim they're the best thing ever. The placebo effect really works."
Source: www.huffingtonpost.com

Eva Norlyk Smith, Ph.D.: 5 Tips To Avoid Yoga Injuries

Eva Norlyk Smith, Ph.D.: 5 Tips To Avoid Yoga Injuries

Can yoga wreck your body? A recent article in the New York Times argues that it can, quoting the increase of yoga-related injuries in recent years as the number of yoga practitioners has soared.

Indeed, the number of yoga injuries treated in emergency rooms or doctors' offices rose to 5,500 in 2007, according to the Consumer Products Safety Commission. The same year, the number of yoga practitioners reached an estimated 15.8 million. That pegs the number of injuries at 0.035 percent, or about 3.5 out of every 10,000 practitioners.

Can weight training wreck your body? Between 1990 to 2007, an estimated 970,000 weight training-related injuries were treated in U.S. hospital emergency rooms, according to the American Journal of Sports Medicine. That's an average of 57,000 injuries per year among an estimated 37 to 45 million practitioners, or roughly 0.12 to 0.15 percent, about 1.2 to 1.5 out of every 1,000 practitioners.

Can golfing wreck your body? In 2007, an estimated 103,000 of the nation's estimated 26.2 million golf players visited the emergency room for golfing-related injuries, according to data from the Consumer Products Safety Commission. That's 0.39 percent, or 3.9 out of every 1,000 golf players incurring an injury.

Any type of physical activity aiming to increase fitness carries with it a certain degree of risk. Pegged next to the injury rate of common physical activities like weight training and golf, however, yoga comes across as far safer than even a relatively innocuous activity like golf (ignoring for the moment that yoga is not just about fitness).

Exercise improves health by challenging the body, triggering changes that make the body stronger: increased muscle mass, stronger bones, greater flexibility, coordination and range of motion -- depending on what is targeted. That is the core of what makes exercise work, but that is also what makes any type of exercise program carry some degree of risk.

As the above statistics indicate, however, making claims about the injury risks of yoga without backing them up by the relative percentage risk is at best poor reporting, at worst could discourage someone from trying yoga who might otherwise benefit from the practice.

Yoga has more than 50 well-documented health benefits according to Dr. Tim McCall, author of Yoga as Medicine. Numerous studies on yoga as therapy demonstrate that yoga offers not just effective stress management, but also is a useful complement in the treatment of diabetes, cancer, MS, heart disease, back pain and many more conditions. Physicians, for example Dr. Loren Fishman, have effectively used yoga in the treatment of numerous debilitating musculoskeletal issues, including rotator cuff tears, back pain, sciatica and much more.

That being said, any type of physical activity that challenges the body should be practiced with awareness and caution. To help you develop the safest possible yoga practice, follow these five tips:

1. Adopt a beginner's mind. You wouldn't go into an advanced ballet or kickboxing class without working your way up through the basics first. Yoga may look comparatively more simple, but it's not. Start with a series of yoga classes targeting beginners, which introduces you to the basics in a systematic way. Not all studios offer intro courses for beginners, so look around. Make sure you build a solid foundation of knowledge of alignment before you try your hand at more challenging classes like a rigorous Vinyasa flow class or a hot yoga class.

2. Learn to listen to your body. In any yoga class, your body, not the teacher, is the real guide to what is best for you. Listening to your body and honoring its signals is key to a safe practice. If something doesn't feel right, ease out of the pose. If something feels like a strain, you're pushing too hard. If your body feels like it needs a break, relax back in child's pose.

3. Do your own pose, not your neighbor's. For most of us, the mind tends to overrule the body. So if the person next to you gets her face all the way down to her shins in Paschimottasana (seated forward bend), by golly, you're gonna get there too, no matter how much your hamstrings howl. However, yoga at its essence is about getting in tune with your body. The only right way to practice a pose is to practice it in the way that honors where your body is at, and not trying to force yourself into your neighbor's pose.

4. Look for your intelligent edge. Look for the sweet spot in every pose. That is where you are challenging the body and yourself, but still staying completely within your comfort zone. Your intelligent edge is that place in the posture where you are feeling a soothing stretch and your muscles are working, but there is no pain, strain or fatigue.

5. Pick the right teacher and approach. When it comes to practicing and teaching yoga, it's not a one size fits all. Yoga teachers vary in approach, style, experience and training. If you're young and fit, you will be able to handle a wide range of yoga styles and classes. On the other hand, if you're a 50+ year old male with super tight hamstrings just starting out, it may be better to start with individual yoga sessions with an experienced teacher. The same thing applies if you have any injuries or physical limitations you're working with. Let your teacher know before the class, and don't be shy to ask if the class will still be suitable for you. If the teacher isn't able to offer specific feedback related to your condition, that's a good indication the teacher might not a good fit for you.

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Source: www.huffingtonpost.com