Archive for the ‘amateur sports’ Category

Researchers at The University of Auckland have shown for the first time that the mere presence of carbohydrate solution in the mouth immediately boosts muscle strength, even before it is swallowed.

The results suggest that a previously unknown neural pathway is activated when receptors in the mouth detect carbohydrate, stimulating parts of the brain that control muscle activity and producing an increase in muscle strength.

Previous research had shown that the presence of carbohydrate in the mouth can improve physical performance during prolonged activity, but the mechanism involved was not known and it was unclear whether a person must be fatigued for the effect to be seen.

“There appears to be a pathway in the brain that tells our muscles when energy is on the way,” says lead researcher Dr Nicholas Gant from the Department of Sport and Exercise Science.

“We have shown that carbohydrate in the mouth produces an immediate increase in neural drive to both fresh and fatigued muscle and that the size of the effect is unrelated to the amount of glucose in the blood or the extent of fatigue.”

The current research has been published in the journal Brain Research and has also captured the attention of New Scientist magazine.

In the first of two experiments, 16 healthy young men who had been doing biceps exercises for 11 minutes were given a carbohydrate solution to drink or an identically flavored energy-free placebo. Their biceps strength was measured before and immediately afterward, as was the activity of the brain pathway known to supply the biceps.

Around one second after swallowing the drink, neural activity increased by 30 percent and muscle strength two percent, with the effect lasting for around three minutes. The response was not related to the amount of glucose in the bloodstream or how fatigued the participants were.

“It might not sound like much, but a two percent increase in muscle strength is enormous, especially at the elite level. It’s the difference between winning an Olympic medal or not,” says co-author Dr Cathy Stinear.

As might be expected, a second boost in muscle strength was observed after 10 minutes when carbohydrate reached the bloodstream and muscles through digestion, but no additional boost in neural activity was seen at that time.

“Two quite distinct mechanisms are involved,” says Dr Stinear. “The first is the signal from the mouth via the brain that energy is about to be available and the second is when the carbohydrate actually reaches the muscles and provides that energy,” says Dr Stinear.

“The carbohydrate and placebo solutions used in the experiment were of identical flavor and sweetness, confirming that receptors in the mouth can process other sensory information aside from the basic taste qualities of food. The results suggest that detecting energy may be a sixth taste sense in humans,” says Dr Gant.

In the second experiment, 17 participants who had not been doing exercise and were not fatigued simply held one of the solutions in their mouths without swallowing. Measurements of the muscle between the thumb and index finger were taken while the muscle was either relaxed or active.

A similar, though smaller effect was observed as in the first experiment, with a nine percent increase in neural activity produced by the carbohydrate solution compared with placebo. This showed that the response is seen in both large powerful muscles and in smaller muscles responsible for fine hand movements.

“Together the results show that carbohydrate in the mouth activates the neural pathway whether or not muscles are fatigued. We were surprised by this, because we had expected that the response would be part of the brain’s sophisticated system for monitoring energy levels during exercise,” says Dr Stinear.

“Seeing the same effect in fresh muscle suggests that it’s more of a simple reflex – part of our basic wiring – and it appears that very ancient parts of the brain such as the brainstem are involved. Reflexive movements in response to touch, vision and hearing are well known but this is the first time that a reflex linking taste and muscle activity has been described,” she says.

Further research is required to determine the precise mechanisms involved and to learn more about the size of the effect on fresh versus fatigued muscle.

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Article adapted by MD Sports from original press release.
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Contact: Pauline Curtis
The University of Auckland

Researchers at The University of Auckland have shown for the first time that the mere presence of carbohydrate solution in the mouth immediately boosts muscle strength, even before it is swallowed.

The results suggest that a previously unknown neural pathway is activated when receptors in the mouth detect carbohydrate, stimulating parts of the brain that control muscle activity and producing an increase in muscle strength.

Previous research had shown that the presence of carbohydrate in the mouth can improve physical performance during prolonged activity, but the mechanism involved was not known and it was unclear whether a person must be fatigued for the effect to be seen.

“There appears to be a pathway in the brain that tells our muscles when energy is on the way,” says lead researcher Dr Nicholas Gant from the Department of Sport and Exercise Science.

“We have shown that carbohydrate in the mouth produces an immediate increase in neural drive to both fresh and fatigued muscle and that the size of the effect is unrelated to the amount of glucose in the blood or the extent of fatigue.”

The current research has been published in the journal Brain Research and has also captured the attention of New Scientist magazine.

In the first of two experiments, 16 healthy young men who had been doing biceps exercises for 11 minutes were given a carbohydrate solution to drink or an identically flavored energy-free placebo. Their biceps strength was measured before and immediately afterward, as was the activity of the brain pathway known to supply the biceps.

Around one second after swallowing the drink, neural activity increased by 30 percent and muscle strength two percent, with the effect lasting for around three minutes. The response was not related to the amount of glucose in the bloodstream or how fatigued the participants were.

“It might not sound like much, but a two percent increase in muscle strength is enormous, especially at the elite level. It’s the difference between winning an Olympic medal or not,” says co-author Dr Cathy Stinear.

As might be expected, a second boost in muscle strength was observed after 10 minutes when carbohydrate reached the bloodstream and muscles through digestion, but no additional boost in neural activity was seen at that time.

“Two quite distinct mechanisms are involved,” says Dr Stinear. “The first is the signal from the mouth via the brain that energy is about to be available and the second is when the carbohydrate actually reaches the muscles and provides that energy,” says Dr Stinear.

“The carbohydrate and placebo solutions used in the experiment were of identical flavor and sweetness, confirming that receptors in the mouth can process other sensory information aside from the basic taste qualities of food. The results suggest that detecting energy may be a sixth taste sense in humans,” says Dr Gant.

In the second experiment, 17 participants who had not been doing exercise and were not fatigued simply held one of the solutions in their mouths without swallowing. Measurements of the muscle between the thumb and index finger were taken while the muscle was either relaxed or active.

A similar, though smaller effect was observed as in the first experiment, with a nine percent increase in neural activity produced by the carbohydrate solution compared with placebo. This showed that the response is seen in both large powerful muscles and in smaller muscles responsible for fine hand movements.

“Together the results show that carbohydrate in the mouth activates the neural pathway whether or not muscles are fatigued. We were surprised by this, because we had expected that the response would be part of the brain’s sophisticated system for monitoring energy levels during exercise,” says Dr Stinear.

“Seeing the same effect in fresh muscle suggests that it’s more of a simple reflex – part of our basic wiring – and it appears that very ancient parts of the brain such as the brainstem are involved. Reflexive movements in response to touch, vision and hearing are well known but this is the first time that a reflex linking taste and muscle activity has been described,” she says.

Further research is required to determine the precise mechanisms involved and to learn more about the size of the effect on fresh versus fatigued muscle.

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Article adapted by MD Sports from original press release.
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Contact: Pauline Curtis
The University of Auckland

University of Pittsburgh School of Medicine researchers have successfully used gene therapy to accelerate muscle regeneration in experimental animals with muscle damage, suggesting this technique may be a novel and effective approach for improving skeletal muscle healing, particularly for serious sports-related injuries. These findings are being presented at the American Society of Gene Therapy annual meeting in Baltimore, May 31 to June 4.

Skeletal muscle injuries are the most common injuries encountered in sports medicine. Although such injuries can heal spontaneously, scar tissue formation, or fibrosis, can significantly impede this process, resulting in incomplete functional recovery. Of particular concern are top athletes, who, when injured, need to recover fully as quickly as possible.
In this study, the Pitt researchers injected mice with a gene therapy vector containing myostatin propeptide–a protein that blocks the activity of the muscle-growth inhibitor myostatin–three weeks prior to experimentally damaging the mice’s skeletal muscles. Four weeks after skeletal muscle injury, the investigators observed an enhancement of muscle regeneration in the gene-therapy treated mice compared to the non-gene-therapy treated control mice. There also was significantly less fibrous scar tissue in the skeletal muscle of the gene-therapy treated mice compared to the control mice.
According to corresponding author Johnny Huard, Ph.D., the Henry J. Mankin Endowed Chair and Professor in Orthopaedic Surgery, University of Pittsburgh School of Medicine, and Director of the Stem Cell Research Center of Children’s Hospital of Pittsburgh, this approach offers a significant, long-lasting method for treating serious, sports-related muscle injuries.
“Based on our previous studies, we expect that gene-therapy treated cells will continue to overproduce myostatin propeptide for at least two years. Since the remodeling phase of skeletal muscle healing is a long-term process, we believe that prolonged expression of myostatin propeptide will continue to contribute to recovery of injured skeletal muscle by inducing an increase in muscle mass and minimizing fibrosis. This could significantly reduce the amount of time an athlete needs to recover and result in a more complete recovery,” he explained.
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Others involved in this study include, Jinhong Zhu, M.D., Yong Li, M.D., Ph.D., of the Growth and Development Laboratory, Children’s Hospital of Pittsburgh; and Chunping Qiao, M.D., and Xiao Xiao, M.D., Ph.D., of the Molecular Therapies Laboratory, department of orthopaedic surgery, University of Pittsburgh School of Medicine.
University of Pittsburgh School of Medicine researchers have successfully used gene therapy to accelerate muscle regeneration in experimental animals with muscle damage, suggesting this technique may be a novel and effective approach for improving skeletal muscle healing, particularly for serious sports-related injuries.
Skeletal muscle injuries are the most common injuries encountered in sports medicine. Although such injuries can heal spontaneously, scar tissue formation, or fibrosis, can significantly impede this process, resulting in incomplete functional recovery. Of particular concern are top athletes, who, when injured, need to recover fully as quickly as possible.
In this study, the Pitt researchers injected mice with a gene therapy vector containing myostatin propeptide–a protein that blocks the activity of the muscle-growth inhibitor myostatin–three weeks prior to experimentally damaging the mice’s skeletal muscles. Four weeks after skeletal muscle injury, the investigators observed an enhancement of muscle regeneration in the gene-therapy treated mice compared to the non-gene-therapy treated control mice. There also was significantly less fibrous scar tissue in the skeletal muscle of the gene-therapy treated mice compared to the control mice.
According to corresponding author Johnny Huard, Ph.D., the Henry J. Mankin Endowed Chair and Professor in Orthopaedic Surgery, University of Pittsburgh School of Medicine, and Director of the Stem Cell Research Center of Children’s Hospital of Pittsburgh, this approach offers a significant, long-lasting method for treating serious, sports-related muscle injuries.
“Based on our previous studies, we expect that gene-therapy treated cells will continue to overproduce myostatin propeptide for at least two years. Since the remodeling phase of skeletal muscle healing is a long-term process, we believe that prolonged expression of myostatin propeptide will continue to contribute to recovery of injured skeletal muscle by inducing an increase in muscle mass and minimizing fibrosis. This could significantly reduce the amount of time an athlete needs to recover and result in a more complete recovery,” he explained.
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Article adapted by MD Sports from original press release.
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Contact: Jim Swyers

Others involved in this study include, Jinhong Zhu, M.D., Yong Li, M.D., Ph.D., of the Growth and Development Laboratory, Children’s Hospital of Pittsburgh; and Chunping Qiao, M.D., and Xiao Xiao, M.D., Ph.D., of the Molecular Therapies Laboratory, department of orthopaedic surgery, University of Pittsburgh School of Medicine.

Cereal and non-fat milk is as good as a commercially-available sports drink in initiating post-exercise muscle recovery.

Background

This study compared the effects of ingesting cereal and nonfat milk (Cereal) and a carbohydrate-electrolyte sports drink (Drink) immediately following endurance exercise on muscle glycogen synthesis and the phosphorylation state of proteins controlling protein synthesis: Akt, mTOR, rpS6 and eIF4E.

Methods

Trained cyclists or triathletes (8 male: 28.0+/-1.6 yrs, 1.8+/-0.0 m, 75.4+/-3.2 kg, 61.0+/-1.6 ml O2 * kg-1 * min-1; 4 female: 25.3+/-1.7 yrs, 1.7+/-0.0 m, 66.9+/-4.6 kg, 46.4+/-1.2 mlO2 * kg-1 * min-1) completed two randomly-ordered trials serving as their own controls. After 2 hours of cycling at 60-65% VO2MAX, a biopsy from the vastus lateralis was obtained (Post0), then subjects consumed either Drink (78.5 g carbohydrate) or Cereal (77 g carbohydrate, 19.5 g protein and 2.7 g fat). Blood was drawn before and at the end of exercise, and at 15, 30 and 60 minutes after treatment. A second biopsy was taken 60 minutes after supplementation (Post60). Differences within and between treatments were tested using repeated measures ANOVA.

Results

At Post60, blood glucose was similar between treatments (Drink 6.1+/-0.3, Cereal 5.6+/-0.2 mmol/L, p<.05), but after Cereal, plasma insulin was significantly higher (Drink 123.1+/-11.8, Cereal 191.0+/-12.3 pmol/L, p<.05), and plasma lactate significantly lower (Drink 1.4+/-0.1, Cereal 1.00+/-0.1 mmol/L, p<.05). Except for higher phosphorylation of mTOR after Cereal, glycogen and muscle proteins were not statistically different between treatments. Significant Post0 to Post60 changes occurred in glycogen (Drink 52.4+/-7.0 to 58.6+/-6.9, Cereal 58.7+/-9.6 to 66.0+/-10.0 mumol/g, p<.05) and rpS6 (Drink 17.9+/-2.5 to 35.2+/-4.9, Cereal 18.6+/-2.2 to 35.4+/-4.4 %Std, p<.05) for each treatment, but only Cereal significantly affected glycogen synthase (Drink 66.6+/-6.9 to 64.9+/-6.9, Cereal 61.1+/-8.0 to 54.2+/-7.2%Std, p<.05), Akt (Drink 57.9+/-3.2 to 55.7+/-3.1, Cereal 53.2+/-4.1 to 60.5+/-3.7 %Std, p<.05) and mTOR (Drink 28.7+/-4.4 to 35.4+/-4.5, Cereal 23.0+/-3.1 to 42.2+/-2.5 %Std, p<.05). eIF4E was unchanged after both treatments.

Conclusion

These results suggest that Cereal is as good as a commercially-available sports drink in initiating post-exercise muscle recovery.

Author: Lynne Kammer, Zhenping Ding, Bei Wang, Daiske Hara, Yi-Hung Liao and John L. Ivy

Credits/Source: Journal of the International Society of Sports Nutrition 2009, 6:11

Research news from Journal of Mass Spectrometry

A new mass spectrometry test can help sports anti-drug doping officials to detect whether an athlete has used drugs that boost naturally occurring steroid levels. The test is more sensitive compared to previous alternatives, more capable of revealing specific suspicious chemical in the body, faster to perform, and could be run on standard drug-screening laboratory equipment. The new test is announced in a special issue of the Journal of Mass Spectrometry that concentrates on detecting drugs in sports.

One of the roles of the masculinising hormone testosterone is to increase muscle size and strength. Taking extra testosterone, or taking a chemical that the body can use to create extra testosterone, could therefore enhance an athlete’s performance. For this reason taking it is banned by the World Anti-Doping Agency (WADA).

The exact level of testosterone varies considerably between different people, so simply measuring total testosterone in an athlete’s urine can not show whether he or she has deliberately taken extra. There is, however, a second chemical in the body, epitestosterone, which is normally present in approximately equal proportions to testosterone. Comparing the ratio of testosterone to epitestosterone can then indicate whether testosterone or a precursor has been taken.

The problem is that it is not always easy to measure these two substances, particularly as they are only present in urine at very low concentrations.

A team of scientists the Sports Medicine Research and Testing Laboratory at the University of Utah have developed a test that makes use of liquid chromatography-tandem mass spectrometry. This method has incredibly high sensitivity (down to 1 ng/ml) and increases the power with which officials can search for both testosterone and epitestosterone within a sample.

“Our system means that we can determine the testosterone/epitestosterone ratio in a sample with greater confidence, and therefore be in a better position to spot doping violations without falsely accusing innocent athletes,” says lead investigator Dr Jonathan Danaceau.

“Not only is the test more sensitive, it is also faster to perform,” says colleague Scott Morrison.

“Having this sort of test available makes cheating harder and lets us take one more step towards enabling free and fair competition,” says Laboratory Director Dr Matthew Slawson.

This paper is part of a special issue for the Olympic Games from the Journal of Mass Spectrometry which focuses of drug use in sport. The issue is available free of charge online for one month at http://www.interscience.wiley.com/journal/jms. The other articles publishing in this issue are:

 

  • History of Mass Spectrometry at Olympic Games (DOI: 10.1002/jms.1445)
  • Nutritional supplements cross-contaminated and faked with doping substances (DOI: 10.1002/jms.1452)
  • Hair analysis of anabolic steroids in connection with doping control results from horse samples (DOI: 10.1002/jms.1446)
  • Mass spectrometric determination of Gonadotrophin releasing hormone (GnRH) in human urine for doping control purposes by means of LC-ESI-MS/MS (DOI: 10.1002/jms.1438)
  • Liquid chromatographic-mass spectrometric analysis of glucuronide-conjugated anabolic steroid metabolites: method validation and inter-laboratory comparison (DOI: 10.1002/jms.1434)
  • Mass Spectrometry of Selective Androgen Receptor Modulators (DOI: 10.1002/jms.1438)
  • Can glycans unveil the origin of glycoprotein hormones? – human chorionic gonadotropin as an example (DOI: 10.1002/jms.1448)
  • A High-Throughput Multicomponent Screening Method for Diuretics, Masking Agents, Central Nervous System Stimulants and Opiates in Human Urine by UPLC-MS/MS (DOI: 10.1002/jms.1436)
  • The application of carbon isotope ratio mass spectrometry to doping control (DOI: 10.1002/jms.1437)
  • Identification of zinc-alpha-2-glycoprotein binding to clone ae7a5 anti-human epo antibody by means of nano-hplc and high-resolution highmass accuracy esi-ms/ms (DOI: 10.1002/jms.1444)
  • Low LC-MS/MS Detection of Glycopeptides Released from pmol Levels of Recombinant Erythropoietin using Nanoflow HPLC-Chip Electrospray Ionization (DOI: 10.1002/jms.1439)
  • Introduction of HPLC/Orbitrap mass spectrometry as screening method for doping control (DOI: 10.1002/jms.1447)

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Article adapted by MD Sports from original press release.
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Contact: Jennifer Beal
Wiley-Blackwell

Investigators in The Research Institute at Nationwide Children’s Hospital have identified the role of a protein that could potentially lead to new clinical treatments to combat musculoskeletal diseases, including Duchenne muscular dystrophy (DMD).

Results of these studies appear in the March 11, 2008 issue of the Proceedings of the National Academy of Sciences.

These studies, led by Brian Kaspar, PhD, a principal investigator in the Center for Gene Therapy at The Research Institute and an assistant professor of Pediatrics at The Ohio State University, focus on a protein called follistatin (FS). Using a single injection, gene-delivery strategy involving FS, investigators treated the hind leg muscles of mice. Results showed increased muscle size and strength, quadruple that of mice treated with proteins other than FS. The muscle enhancements were shown to be well-tolerated for more than two years.

According to Dr. Kaspar, increased muscle mass and strength were also evident when this strategy was tested using a model of DMD. Apart from the injected hind leg muscles, strengthening effects were also shown in the triceps. In addition, fibrosis, abnormal formation of scar tissue and a hallmark of muscular dystrophy, was decreased in FS-treated animals.

“We believe this new FS strategy may be more powerful than other strategies due to its additional effects, including its ability to reduce inflammation,” said Dr. Kaspar.

The strategy showed no negative effects on the heart or reproductive ability of either males or females. The results were also replicated in older animals, suggesting that this strategy could be useful in developing clinical treatments for older DMD patients.

“This research provides evidence of multiple potential treatment applications for muscle diseases including, but not limited to, muscular dystrophy,” said Jerry Mendell, MD, director of the Center for Gene Therapy at The Research Institute, a co-author on the study, and professor of Pediatrics in Neurology and Pathology at The Ohio State University. “These results offer promise for treatment of potentially any muscle-wasting disease, including muscle weakness due to other illnesses, aging, and inflammatory diseases such as polymyositis. Our next step is to pursue clinical trials.”

The Research Institute at Nationwide Children’s Hospital has a patent pending on the FS technique due to the major role it may play for muscular dystrophy treatment and other muscle-wasting diseases.

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Article adapted by MD Sports from original press release.
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Contact: Pam Barber/Mary Ellen Fiorino
Nationwide Children’s Hospital

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

Neuroscience researchers at the Duke-NUS Graduate Medical School in Singapore have shown for the first time what happens to the visual perceptions of healthy but sleep-deprived volunteers who fight to stay awake, like people who try to drive through the night.

The scientists found that even after sleep deprivation, people had periods of near-normal brain function in which they could finish tasks quickly. However, this normalcy mixed with periods of slow response and severe drops in visual processing and attention, according to their paper, published in the Journal of Neuroscience on May 21.

“Interestingly, the team found that a sleep-deprived brain can normally process simple visuals, like flashing checkerboards. But the ‘higher visual areas’ – those that are responsible for making sense of what we see – didn’t function well,” said Dr. Michael Chee, lead author and professor at the Neurobehavioral Disorders Program at Duke-NUS. “Herein lies the peril of sleep deprivation.”

The research team, including colleagues at the University of Michigan and University of Pennsylvania, used magnetic resonance imaging to measure blood flow in the brain during speedy normal responses and slow “lapse” responses. The study was funded by grants from the DSO National Laboratories in Singapore, the National Institutes of Health, the National Institute on Drug Abuse, the NASA Commercialization Center, and the Air Force Office of Scientific Research.

Study subjects were asked to identify letters flashing briefly in front of them. They saw either a large H or S, and each was made up of smaller Hs or Ss. Sometimes the large letter matched the smaller letters; sometimes they didn’t. Scientists asked the volunteers to identify either the smaller or the larger letters by pushing one of two buttons.

During slow responses, sleep-deprived volunteers had dramatic decreases in their higher visual cortex activity. At the same time, as expected, their frontal and parietal ‘control regions’ were less able to make their usual corrections.

Scientists also could see brief failures in the control regions during the rare lapses that volunteers had after a normal night’s sleep. However, the failures in visual processing were specific only to lapses that occurred during sleep deprivation.

The scientists theorize that this sputtering along of cognition during sleep deprivation shows the competing effects of trying to stay awake while the brain is shutting things down for sleep. The brain ordinarily becomes less responsive to sensory stimuli during sleep, Chee said.

This study has implications for a whole range of people who have to struggle through night work, from truckers to on-call doctors. “The periods of apparently normal functioning could give a false sense of competency and security when in fact, the brain’s inconsistency could have dire consequences,” Chee said.

“The study task appeared simple, but as we showed in previous work, you can’t effectively memorize or process what you see if your brain isn’t capturing that information,” Chee said. “The next step in our work is to see what we might do to improve things, besides just offering coffee, now that we have a better idea where the weak links in the system are.”

 

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Article adapted by MD Sports from original press release.
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Contact: Mary Jane Gore
Duke University Medical Center

Other authors of the study include Jiat Chow Tan, Hui Zheng, and Sarayu Parimal of the Cognitive Neuroscience Lab at the Duke-NUS Graduate Medical School; Daniel Weissman of the University of Michigan Psychology Department; David Dinges of the University of Pennsylvania School of Medicine; and Vitali Zagorodnov of the Computer Engineering Department of the Nanyang Technological University in Singapore.

Researchers from the Division of Health Promotion & Sports Medicine at Oregon Health & Science University have found steroid use among teen girls is not limited to athletes and often goes hand in hand with other unhealthy choices, including smoking and taking diet pills. The study was published in the Archives of Pediatrics & Adolescent Medicine, a JAMA/Archives journal.Diane Elliot, M.D., professor of medicine (health promotion and sports medicine), OHSU School of Medicine, and colleagues analyzed findings from the Center for Disease Control’s Youth Risk Behavior Survey of 7,544 ninth- through 12th-grade girls from around the country. The questionnaire asked about sports participation, anabolic steroid and drug use, and other illegal or unhealthy behaviors. Approximately 5 percent of participants reported prior or ongoing anabolic steroid use.

In addition to greater substance use, young female steroid users were more likely to have had sexual intercourse before age 13; have been pregnant; drink and drive or have ridden with a drinking driver; carry a weapon; have been in a fight on school property; have feelings of sadness or hopelessness almost every day for at least two weeks; and have attempted suicide. Those reporting anabolic steroid use were less likely to participate in team athletics.

Overall, more than two-thirds of those surveyed reported trying to change their weight. Girls who used steroids were more likely try extreme weight-loss techniques, such as vomiting and laxative use.

Adolescent girls reporting anabolic steroid use had significantly more other health-harming behaviors, Elliot explained, “They were much more likely to use other unhealthy substances, including cigarettes, alcohol, marijuana and cocaine.”

“Across all grades, these seem to be troubled adolescents with co-occurring health-compromising activities in the domains of substance use, sexual behavior, violence and mental health,” Elliot said. “Anabolic steroid use is a marker for high-risk girls. High-risk young women have received less attention than young men, perhaps reflecting that their actions are less socially, albeit more personally, destructive. Further study is needed to develop effective interventions for these young women.”

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Article adapted by MD Sports Weblog from original press release.
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Contact: Tamara Hargens
Oregon Health & Science University

Baseball team owners, players and fans seem to agree on the importance of drug testing for steroids, according to current reports, but the entire scope of performance-enhancing substances available for all athletes is vastly broader and many of the drugs employed by athletes are not easily detectable, says a Penn State researcher.”The use, misuse and abuse of drugs have long shaken the foundations of amateur and professional sports–baseball, football, track and field, gymnastics and cycling, to name just a few,” says Dr. Charles Yesalis, Penn State professor of exercise and sport science and health policy and administration. “The problem is not new. But like the rest of technology, doping in sport has grown in scientific and ethical complexity. In addition to drugs, we have natural hormones, blood doping, diuretics, nutritional supplements, social and recreational drugs, stimulants and miscellaneous substances, some of which may not even be on any list of banned substances.”

While drug testing technology struggles to keep up, an array of new and emerging technologies has arrived or is on the horizon with potential for abuse by athletes including gene transfer therapy, stem cell transplantation, muscle fiber phenotype transformation, red blood cell substitutes and new drug delivery systems, says Yesalis

“It is not too hard to imagine the day when muscles can be selectively enlarged or contoured,” according to the book. “Just imagine the consequences of a kinesiologist isolating specific muscles and selectively injecting designer genes into those muscles to maximize their function.”

The new book brings together the latest and most comprehensive scientific information about performance-enhancing substances, as well as discussion of drug testing, legal and social issues, and future directions by sports governing organizations.

“Sport has a responsibility to maintain a level playing field for the trial of skill,” Yesalis says. “The use of chemical and pharmacologist agents is cheating – just like using a corked baseball bat. But unlike the bat, doping is shrouded in mystery. Athletes and their advisors are constantly seeking ‘gray areas” surrounding the rules, and if something is not explicitly banned, then why not try it. This slippery slope of rationalization is treacherous and appealing to a player or team seeking glory and money rewards.”

In one chapter, “Drug Testing and Sport and Exercise,” author R. Craig Kammerer suggests that improvement in current tests and developments in new methods will assist future policymaking by athletic federations. However, effective testing must become more widespread and include unannounced testing outside of competition. Sanctions against athletes must be more fairly and uniformly applied, with thorough investigation to avoid false positive results and ruin an athlete’s career.

The difficulty of detecting and preventing the abuse of performance enhancing substances by adult athletes may seem futile but remains necessary as part of the effort to discourage abuse by youths who emulate professional athletes and also seek a winning advantage, Yesalis notes.

A recent government study of adolescent drug use shows an alarming increase in anabolic steroid use among middle school youths from 1998-1999 with an estimated 2.7 percent of eighth graders saying they have used the drugs. A larger survey by Blue Cross and Blue Shield estimates that one million U.S. children between the ages of 12 and 17 may have taken performance-enhancing substances including creatine, according to the book.

“Children and teens can seriously harm their future health by misusing these substances,” Yesalis says. “For example, steroids alone can cause scarring acne, hair loss and testicular atrophy, and may increase the risk of stroke and heart disease. It is just as important to note that little is known about the health consequences of many of the other substances used to enhance performance. Yet some coaches and parents look the other way and even actively encourage the use of performance-enhancing substances in pursuit of scholarships and winning.

“There is too much fame and fortune to be gained by being a winner in sports,” he notes. “It’s interesting to see that baseball fans being polled support drug testing and a ban on steroids, but it will take fans of all major sports to take a stand by turning off their TV sets or not buying a ticket to sports events before adult athletes, coaches and team owners stop trying to cheat. And, that’s probably not going to happen.”

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Article adapted by MD Sports Weblog from original press release.
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Contact: Vicki Fong
Penn State