G-Trainer: Low-gravity training machine reduces joint and muscle discomfort

A University of Colorado at Boulder study of a space-age, low-gravity training machine used by several 2008 Olympic runners showed it reduced impacts on muscles and joints by nearly half when subjects ran at the equivalent of 50 percent of their body weight.

The new study has implications for both competitive runners rehabilitating from injuries and for ordinary people returning from knee and hip surgeries, according to Associate Professor Rodger Kram of CU-Boulder’s integrative physiology department.

Known as the “G-Trainer,” the machine consists of a treadmill surrounded by an inflatable plastic chamber that encases the lower body of the runner, said Kram. Air pumped into the chamber increases the pressure and effectively reduces the weight of runners, who are sealed in the machine at the waist in a donut-shaped device with a special zipper and “literally lifted up by their padded neoprene shorts,” he said.

Published in the August issue of the Journal of Applied Biomechanics, the study is the first to quantify the effects of running in the G-Trainer, built by Alter-G Inc. of Menlo Park, Calif., using technology developed at NASA’s Ames Research Center in California. The paper was authored by Kram and former CU-Boulder doctoral student Alena Grabowski, now a postdoctoral researcher at the Massachusetts Institute of Technology.

Although G-Trainers have been used in some sports clinics and college and professional sports training rooms since 2006, the new study is the first scientific analysis of the device as a training tool for running, said Grabowski.

“The idea was to measure which levels of weight support and speeds give us the best combination of aerobic workout while reducing the impact on joints,” said Kram. “We showed that a person can run faster in the G-Trainer at a lower weight and still get substantial aerobic benefits while maintaining good neuromuscular coordination.”

The results indicated a subject running at the equivalent of half their weight in the G-Trainer at about 10 feet per second, for example — the equivalent of a seven-minute mile — decreased the “peak” force resulting from heel impact by 44 percent, said Grabowski. That is important, she said, because each foot impact at high speed can jar the body with a force equal to twice a runner’s weight.

Several former CU track athletes participating in the 2008 Olympics in Beijing have used the machine, said Kram. Alumna Kara Goucher, who will be running the 5,000- and 10,000-meter races in Beijing, has used the one in Kram’s CU-Boulder lab and one in Eugene, Ore., for rehabilitation, and former CU All-American and Olympic marathoner Dathan Ritzenhein also uses a G-Trainer in his home in Oregon. Other current CU track athletes who have been injured have tried the machine in Kram’s lab and found it helpful to maintain their fitness as they recovered, Kram said.

For the study, the researchers retrofitted the G-Trainer with a force-measuring treadmill invented by Kram’s team that charts vertical and horizontal stress load on each foot during locomotion, measuring the variation of biomechanical forces on the legs during running. Ten subjects each ran at three different speeds at various reduced weights, with each run lasting seven minutes. The researchers also measured oxygen consumption during each test, Kram said.

Grabowski likened the effect of the G-Trainer on a runner to pressurized air pushing on the cork of a bottle. “If you can decrease the intensity of these peak forces during running, then you probably will decrease the risk of injury to the runner.”

The G-Trainer is a spinoff of technology originally developed by Rob Whalen, who conceived the idea while working at NASA Ames as a National Research Council fellow to help astronauts maintain fitness during prolonged space flight. While the NASA technology was designed to effectively increase the weight of the astronauts to stem muscle atrophy and bone loss in low-gravity conditions, the G-Trainer reverses the process, said Grabowski.

In the past, sports trainers and researchers have used climbing harnesses over treadmills or flotation devices in deep-water swimming pools to help support the weight of subjects, said Kram. Harnesses are cumbersome, while pool exercises don’t provide sufficient aerobic stimulation and biomechanical loading on the legs, he said.

Marathon world-record holder Paula Radcliffe of Great Britain is currently using a G-Trainer in her high-altitude training base in Font-Remeu, France. Radcliffe is trying to stay in top running shape while recovering from a stress fracture in her femur in time for the 2008 Olympic women’s marathon on Aug. 17, according to the London Telegraph.

Kram and Grabowski have begun a follow-up study of walking using the G-Trainer. By studying subjects walking at various weights and speeds in the machine, the researchers should be able to quantify its effectiveness as a rehabilitation device for people recovering from surgeries, stress fractures and other lower body injuries, Kram said.

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Article adapted by MD Sports from original press release.
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Contact: Rodger Kram
University of Colorado at Boulder

Super protein creates fat burning Metabolic ‘shield” against weight gain…

And it increases endurance to run a mile and decreases inflammation

The Salk Institute scientist who earlier discovered that enhancing the function of a single protein produced a mouse with an innate resistance to weight gain and the ability to run a mile without stopping has found new evidence that this protein and a related protein play central roles in the body’s complex journey to obesity and offer a new and specific metabolic approach to the treatment of obesity related disease such as Syndrome X (insulin resistance, hyperlipidemia and atherosclerosis).

Dr. Ronald M. Evans, a Howard Hughes Medical Investigator at The Salk Institute’s Gene Expression Laboratory, presented two new studies (date) at Experimental Biology 2005 in the scientific sessions of the American Society for Biochemistry and Molecular Biology. The studies focus on genes for two of the nuclear hormone receptors that control broad aspects of body physiology, including serving as molecular sensors for numerous fat soluble hormones, Vitamins A and D, and dietary lipids.

The first study focuses on the gene for PPARd, a master regulator that controls the ability of cells to burn fat. When the “delta switch” is turned on in adipose tissue, local metabolism is activated resulting in increased calorie burning. Increasing PPARd activity in muscle produces the “marathon mouse,” characterized by super-ability for long distance running. Marathon mice contain altered muscle composition, which doubles its physical endurance, enabling it to run an hour longer than a normal mouse. Marathon mice contain increased levels of slow twitch (type I) muscle fiber, which confers innate resistance to weight gain, even in the absence of exercise.

Additional work to be reported at Experimental Biology looks at another characteristic of PPARd: its role as a major regulator of inflammation. Coronary artery lesions or atherosclerosis are thought to be sites of inflammation. Dr. Evans found that activation of PPARd suppresses the inflammatory response in the artery, dramatically slowing down lesion progression. Combining the results of this new study with the original “marathon mouse” findings suggests that PPARd drugs could be effective in controlling atherosclerosis by limiting inflammation and at the same time promoting improved physical performance.

Dr. Evans says he is very excited about the therapeutic possibilities related to activation of the PPARd gene. He believes athletes, especially marathon runners, naturally change their muscle fibers in the same way as seen in the genetically engineered mice, increasing levels of fat-burning muscle fibers and thus building a type of metabolic ‘shield” that keeps them from gaining weight even when they are not exercising.

But athletes do it through long periods of intensive training, an approach unavailable to patients whose weight or medical problems prevent them from exercise. Dr. Evans believes activating the PPARd pathway with drugs (one such experimental drug already is in development to treat people with lipid metabolism) or genetic engineering would help enhance muscle strength, combat obesity, and protect against diabetes in these patients.

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Article adapted by MD Sports Weblog from original press release.
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Contact: Sarah Goodwin
Federation of American Societies for Experimental Biology

10 Steps To Combat Low Back Pain

To celebrate Allied Health Professions Week, the National Athletic Trainers’ Association has prepared a 10-step guide that people of all ages can use to reduce body stress, prevent back pain and thereby improve quality of life – especially with holiday plans and travel just around the corner. Along with the season comes the lifting of heavy suitcases and holiday gifts that can put additional pressure on the back. NATA represents certified athletic trainers who are among the more than 80 professions being honored during Allied Health Professions Week (Nov. 4-10, 2007).

“The human body is an incredible machine that adapts to the stresses we give it every day,” said certified athletic trainer Darrell Barnes, LAT, ATC, CSCS, performance center coordinator, St. Vincent Sports Performance Center in Indianapolis, Ind. “Stresses such as poor posture, unusual movement or activities or even a sedentary lifestyle can lead to poor mechanics and pain. Disability from back pain is second only to the common cold as a cause of lost work time.”

According to the Arthritis Foundation, back pain affects 80 percent of the adult population at some point in their lives. In fact, back pain, limited mobility and stiffness end up costing American consumers $24 billion in treatment costs annually.

Following are recommendations to prevent and reduce back pain now and year-round:

1. Identify negative stresses that may be exacerbated by the holidays – Everybody has physical limitations that can lead to body imbalances, so it’s important to identify problematic areas and correct these imbalances. Look at your sitting/standing posture. Do you complain that your muscles “feel tight” or weak? Do you use poor mechanics when lifting heavy items? Are you putting unusual stress on the back with certain activities and lifting during the holiday season? Learning correct lifting techniques and strengthening your back can help to alleviate pain. Use a luggage cart or lighten your load when lifting heavy packages or luggage.

2. Make yourself mobile – Poor posture and muscle stiffness decrease the body’s ability to move freely, which can lead to injury or pain. There are many ways to increase mobility including daily stretches or activities that increase flexibility and get the body moving in different directions. Try yoga, tai chi, swimming or pilates to keep you limber.

3. Increase strength – It’s important to get strong to improve overall balance and flexibility to reduce stress on the back. Exercises should involve the whole body, especially the core muscles of the stomach, back, hips and pelvis. At the same time, strengthening of the legs and shoulders can help you more easily squat, lift and carry even heavy items without overworking or injuring your back.

4. Add aerobic exercise – Physical activities like walking, swimming and running for at least 20 minutes three times a week increases muscular endurance and cardiovascular fitness. Aerobic activities also improve blood flow to the spine and help decrease daily stress.

5. Pay attention to posture – Try not to sit or drive for long periods of time. Get up every 15 to 30 minutes and move around or stretch to increase your mobility. When seated always remember to keep your hips and knees at right angles to one another and find a chair with adequate lumbar (lower back) support.

6. Stand up straight – When engaged in activities while standing, be sure to stand with your head up, shoulders straight, chest forward and stomach tight. Avoid standing in the same position for too long, though, and use your legs – rather than your back – when pushing or pulling heavy doors and other items.

7. Use proper lifting mechanics – When lifting objects from a position below your waist, stand with a wide stance and a slight bend at your hips and knees. Tighten your stomach as you lift and keep your back as flat as possible – do not arch or bend. When carrying heavy objects, keep them as close to your body as you can. Avoid carrying objects on only one side of your body.

8. Get a good night’s sleep – Select a firm mattress and box spring that does not sag. Try to sleep in a position that allows you to maintain the natural curve in your back.

9. Warm-up before physical activity – Engage in a low impact activity prior to playing sports or exercising. Increasing muscle temperature and mobility will decrease the chance of injury.

10. Improve your healthy lifestyle – Obesity and smoking have been found to increase the incidence of back pain. Taking steps to improve your health will decrease the chance of back pain and improve your overall quality of life.

Barnes also urges people to always listen to their bodies: “If you are participating in any fitness routines or general activity and feel any twinges of back pain, you should stop immediately and consult your physician. Identifying the cause of the pain and treating it safely and appropriately will help you gain back mobility and range of motion and feel your physical best.”

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Article adapted by MD Only Weblog from original press release.
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Contact: Robin Waxenberg 
National Athletic Trainers’ Association

About the National Athletic Trainers’ Association (NATA)

Athletic trainers are unique health care providers who specialize in the prevention, assessment, treatment and rehabilitation of injuries and illnesses. The National Athletic Trainers’ Association represents and supports 30,000 members of the athletic training profession through education and research. Only 42 percent of high schools have access to athletic trainers. NATA advocates for equal access to athletic trainers for athletes and patients of all ages, and supports H.R. 1846.

Endorphins and opioids released during running protect against Heart Attacks

Endorphins and other morphine-like substances known as opioids, which are released during exercise, don’t just make you feel good — they may also protect you from heart attacks, according to University of Iowa researchers.

It has long been known that the so-called “runner’s high” is caused by natural opioids that are released during exercise. However, a UI study, which is published in the online edition of the American Journal of Physiology’s Heart and Circulatory Physiology, suggests that these opioids may also be responsible for some of exercise’s cardiovascular benefits.

Working with rats, UI researchers showed that blocking the receptors that bind morphine, endorphins and other opioids eliminates the cardiovascular benefits of exercise. Moreover, the UI team showed that exercise was associated with increased expression of several genes involved in opioid pathways that appear to be critical in protecting the heart.

“This is the first evidence linking the natural opioids produced during exercise to the cardio-protective effects of exercise,” said Eric Dickson, M.D., UI associate professor and head of emergency medicine in the Roy J. and Lucille A. Carver College of Medicine and the study’s lead investigator. “We have known for a long time that exercise is great for the heart. This study helps us better understand why.”

Studies have shown that regular vigorous exercise reduces the risk of having a heart attack and improves survival rates following heart attack, even in people with cardiovascular disease. In addition, exercise also decreases the risk of atherosclerosis, stroke, osteoporosis and even depression. However, despite these proven health benefits, much less is understood about how exercise produces these benefits.

The UI study investigated the idea that the opioids produced by exercise might have a direct role in cardio-protection. The researchers compared rats that exercised with rats that did not. As expected, exercised rats sustained significantly less heart damage from a heart attack than non-exercised rats. The researchers then showed that blocking opioid receptors completely eliminated these cardio-protective effects in exercising rats, suggesting that opioids are responsible for some of the cardiac benefits of exercise.

The UI team also showed that exercise was associated with transient increases in expression of several opioid system genes in heart muscle, and changes in expression of other genes that are involved in inflammation and cell death. The researchers plan to investigate whether these altered gene expression patterns reveal specific cardio-protective pathways.

A better understanding of how exercise protects the heart may eventually allow scientists to harness these protective effects for patients with decreased mobility.

“Hopefully this study will move us closer to developing therapies that mimic the benefits of exercise,” Dickson said. “It also serves as a reminder of how important it is to get out and exercise every day.”

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Article adapted by MD Only Weblog from original press release.
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Contact: Jennifer Brown
University of Iowa

In addition to Dickson, the UI research team included Christopher Hogrefe, Paula Ludwig, Laynez Ackermann, Lynn Stoll, Ph.D., and Gerene Denning, Ph.D.

STORY SOURCE: University of Iowa Health Science Relations, 5135, Westlawn, Iowa City, Iowa 52242-1178

ORIGINAL ARTICLE: Abstract is available Click here

Pycnogenol® Improves Blood Flow, Relieves Muscle Cramp And Pain In Athletes

A study published in Angiology shows that supplementation with the pine bark extract Pycnogenol® (pic-noj-en-all) improves blood flow to the muscles which speeds recovery after physical exercise. The study of 113 participants demonstrated that Pycnogenol significantly reduces muscular pain and cramps in athletes and healthy, normal individuals.

“With the millions of athletes worldwide, this truly is a profound breakthrough and extremely significant for all individuals interested in muscle cramp and pain relief with a natural approach. These findings indicate that Pycnogenol can play an important role in sports by improving blood flow to the muscles and hastening post-exercise recovery, said Dr. Peter Rohdewald, a lead researcher of the study.

Researchers at L’Aquila University in Italy and at the University of Würzburg in Germany studied the effects of Pycnogenol® on venous disorders and cramping in two separate studies.

The first study consisted of 66 participants who had experienced normal cramping at some point, had venous insufficiency, or were athletes who suffer from exercise-induced cramping. The first two weeks of the study was an observation period and participants did not supplement with Pycnogenol®. Symptoms related to venous disorders, and the number of cramping episodes each participant experienced over the two observation weeks was recorded.

Next, all the participants were given 200 mg of Pycnogenol once a day for four weeks. After the treatment phase, participants’ symptoms and cramping episodes were recorded for one week without any Pycnogenol supplementation.

The researchers found a significant decrease in the number of cramps the participants experienced while supplementing with Pycnogenol.® Participants who had experienced normal cramping had a 25 percent reduction in the number of cramps experienced while taking Pycnogenol.

Participants with venous insufficiency experienced a 40 percent reduction in the number of cramps, and athletes with frequent cramping experienced a 13 percent reduction in the number of cramps while on Pycnogenol.®

The second study involved 47 participants with diabetic microangiopathy (a disorder of the smallest veins commonly associated with diabetes), or intermittent claudication (a blood vessel disease that causes the legs to easily cramp).This study also used a two-week pre-trial observation period followed by a week of supplementing with Pycnogenol (200 mg per day for one week), followed by a week of observation without Pycnogenol® supplementation.

Patients with diabetic microangiopathy had a 20.8 percent reduction in pain, while participants with claudication experienced a 21 percent decrease in the amount of pain experienced while supplementing with Pycnogenol.® Results indicated participants who took placebo experienced no decrease in pain.

Cramps are a common problem for people of all ages, ranging to the extreme fit and healthy to people who suffer from health problems. Previously, magnesium was hailed as the natural approach for relieving muscle cramps, however studies continue to show magnesium to be inefficient for reducing muscle cramps.

“Pycnogenol® improves the blood supply to muscle tissue creating a relief effect on muscle cramping and pain. Poor circulation in the muscle is known to cause cramps and Pycnogenol® improved the cramping in patients due to a stimulation of blood flow to their muscle tissue. Nitric oxide (NO) a blood gas, is well known to enhance blood flow and Pycnogenol® may be influencing the activity of NO,” said Rohdewald. “The insufficient production of NO is the common denominator responsible for impaired blood flow in vascular disease.”

Strenuous exercise is known to involve muscle damage which may be followed by symptoms of inflammation. In separate studies published this year and in 2004 and 2005, Pycnogenol® demonstrated its anti-inflammatory effects in clinical trials for asthma, dysmenorrhea and osteoarthritis.

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Article adapted by MD Only Weblog from original press release.
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Contact: Pycnogenol®

About Pycnogenol®
Pycnogenol® is a natural plant extract originating from the bark of the maritime pine that grows along the coast of southwest France and is found to contain a unique combination of procyanidins, bioflavonoids and organic acids, which offer extensive natural health benefits. The extract has been widely studied for the past 35 years and has more than 220 published studies and review articles ensuring safety and efficacy as an ingredient. Today, Pycnogenol® is available in more than 600 dietary supplements, multi-vitamins and health products worldwide.