Archive for the ‘Weightlifting’ 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

WESTCHESTER, Ill. – Athletes who get an extra amount of sleep are more likely to improve their performance in a game, according to a research abstract presented at the 21st Annual Meeting of the Associated Professional Sleep Societies (APSS).

The study, authored by Cheri Mah of Stanford University, was conducted on six healthy students on the Stanford men’s basketball team, who maintained their typical sleep-wake patterns for a two-week baseline followed by an extended sleep period in which they obtained as much extra sleep as possible. To assess improvements in athletic performance, the students were judged based on their sprint time and shooting percentages.

Significant improvements in athletic performance were observed, including faster sprint time and increased free-throws. Athletes also reported increased energy and improved mood during practices and games, as well as a decreased level of fatigue.

“Although much research has established the detrimental effects of sleep deprivation on cognitive function, mood and performance, relatively little research has investigated the effects of extra sleep over multiple nights on these variables, and even less on the specific relationship between extra sleep and athletic performance. This study illuminated this latter relationship and showed that obtaining extra sleep was associated with improvements in indicators of athletic performance and mood among members of the men’s basketball team.”

The amount of sleep a person gets affects his or her physical health, emotional well-being, mental abilities, productivity and performance. Recent studies associate lack of sleep with serious health problems such as an increased risk of depression, obesity, cardiovascular disease and diabetes.
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Article adapted by MD Sports from original press release.
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Contact: Jim Arcuri
American Academy of Sleep Medicine 

Experts recommend that adults get between seven and eight hours of sleep each night to maintain good health and optimum performance.

Persons who think they might be suffering from a sleep disorder are encouraged to consult with their primary care physician, who will refer them to a sleep specialist.

The annual SLEEP meeting brings together an international body of 5,000 leading researchers and clinicians in the field of sleep medicine to present and discuss new findings and medical developments related to sleep and sleep disorders.

More than 1,000 research abstracts will be presented at the SLEEP meeting, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The four-day scientific meeting will bring to light new findings that enhance the understanding of the processes of sleep and aid the diagnosis and treatment of sleep disorders such as insomnia, narcolepsy and sleep apnea.

ATHENS, Ohio – Men over 60 may be able to increase their strength by as much as 80 percent by performing intense weight training exercises, according to physiologists involved in studies of the health benefits of weight lifting. The researchers also have found that older men gain strength at the same rate as men in their 20s.

In a study of 18 men ages 60 to 75, Ohio University physiologists found that subjects who participated in a 16-week, high-intensity resistence training program on average were 50 percent to 80 percent stronger by the end of the study. None of the participants had engaged in weight lifting prior to the study. Researchers also observed improvements in the seniors’ muscle tone, aerobic capacity and cholesterol profile.

These are some of the latest findings from a decades-long examination of the impact of exercise on the health of men and women of all ages. When researchers compared the strength gains of the elderly participants in this study to findings from other studies they’ve done of college-age men, they found that changes in strength and muscle size were similar in both age groups. The findings were published in a recent issue of the Journal of Gerontology.

“There have been a number of research projects that have come out over the years that suggest there is no age limitation to getting stronger from resistance training,” said Robert Staron, co-author of this study and an associate professor of anatomy in the university’s College of Osteopathic Medicine. “It’s become obvious that it’s important to maintain a certain amount of muscle mass as we age.”

This new study also suggests that elderly men can handle heavy workloads over a long period of time. Participants – who all were in good health and closely monitored during testing and training – performed leg presses, half squats and leg extensions twice a week to exercise the lower body. When the men began the study, they were able to leg press about 375 pounds on average. After the 16-week period, they could take on about 600 pounds. Studies elsewhere have involved low-intensity exercises over a shorter term.

In addition to the increase in strength, researchers found that weight lifting had a beneficial impact on the participants’ cardiovascular system. Tests on an exercise treadmill showed that their bodies used oxygen more efficiently after weight training.

“The individuals run until they are completely exhausted, and it took longer for them to reach that point after resistance training,” Staron said.

Blood samples taken before and after weight training also showed favorable changes in participants’ overall cholesterol profiles, he said, including increases in HDL cholesterol levels and decreases in LDL cholesterol levels.

Losing muscle tone and strength is not uncommon for many senior citizens, Staron said, but this research suggests that a lack of physical exercise can contribute to the problem.

“Certainly, inactivity does play a role in contributing to the decrease in muscle mass,” Staron said. “If we can maintain a certain level of strength through exercise, our quality of life should be better as we age.”

Before beginning a weight lifting regimen, it’s a good idea to consult a physician, Staron advised, adding that it’s also important to learn proper weight lifting techniques. Staron and his colleagues now have turned their attention to how certain weight training routines impact young people.

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Article adapted by MD Sports from original press release.
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Contact: Andrea Gibson
Ohio University

Collaborators on this project are Fredrick Hagerman, Robert Hikida and Thomas Murray of the College of Osteopathic Medicine, former graduate student Seamus Walsh, Roger Gilders of the College of Health and Human Services, Kumika Toma of the College of Arts and Sciences and Kerry Ragg of the Student Health Service.

It’s an inevitable truth: as we get older, our muscles deteriorate and we become weaker. Not only can this be an immensely frustrating change, but it can also have many other, more serious implications. We become clumsier and begin to have more falls, often resulting in broken bones or even more severe injuries. There is wide interest in this phenomenon, but to date, the majority of research has focussed on therapies for older patients with advanced symptoms. Now one study, led by Dr Alexandra Sänger from the University of Salzburg, is taking a new approach: scientists are examining the effects of different exercise regimes in menopausal women, with the aim of developing new strategies for delaying and reducing the initial onset of age related muscle deterioration. Results will be presented on Monday 7th July at the Society for Experimental Biology’s Annual Meeting in Marseille [Poster Session A5].

Dr Sänger’s research group has investigated two particular methods of physical training. Hypertrophy resistance training is a traditional approach designed to induce muscle growth whereas ‘SuperSlow®’ is a more recently devised system which involves much slower movement and fewer repetitions of exercises, and was originally introduced especially for beginners and for rehabilitation. “Our results indicate that both methods increase muscle mass at the expense of connective and fatty tissue, but contrary to expectations, the SuperSlow® method appears to have the greatest effect,” reveals Dr Sänger. “These findings will be used to design specific exercise programmes for everyday use to reduce the risk of injury and thus significantly contribute to a better quality of life in old age.”

The study focussed on groups of menopausal women aged 45-55 years, the age group in which muscle deterioration first starts to become apparent. Groups undertook supervised regimes over 12 weeks, based on each of the training methods. To see what effect the exercise had, thigh muscle biopsies were taken at the beginning and end of the regimes, and microscopically analysed to look for changes in the ratio of muscle to fatty and connective tissue, the blood supply to the muscle, and particularly for differences in the muscle cells themselves. “The results of our experiments have significantly improved our understanding of how muscles respond to different forms of exercise,” asserts Dr Sänger. “We believe that the changes that this new insight can bring to current training systems will have a considerable effect on the lives of both menopausal and older

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Article adapted by MD Sports from original press release.
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Notes to editors

  • Hypertrophy resistance training is a method of strength training that is designed to induce muscle growth, also known as hypertrophy.
  • SuperSlow® resistance training was developed by Ken Hutchins and is based on the same principle as hypertrophy resistance training, but involves slower movement and fewer repetitions of exercises, which is thought to improve the quality of muscle contraction and thereby strength.

Contact: Holly Astley
Society for Experimental Biology

Recipe to recover more quickly from exercise: Finish workout, eat pasta, and wash down with five or six cups of strong coffee.

Glycogen, the muscle’s primary fuel source during exercise, is replenished more rapidly when athletes ingest both carbohydrate and caffeine following exhaustive exercise, new research from the online edition of the Journal of Applied Physiology shows. Athletes who ingested caffeine with carbohydrate had 66% more glycogen in their muscles four hours after finishing intense, glycogen-depleting exercise, compared to when they consumed carbohydrate alone, according to the study, published by The American Physiological Society.

The study, “High rates of muscle glycogen resynthesis after exhaustive exercise when carbohydrate is co-ingested with caffeine,” is by David J. Pedersen, Sarah J. Lessard, Vernon G. Coffey, Emmanuel G. Churchley, Andrew M. Wootton, They Ng, Matthew J. Watt and John A. Hawley. Dr. Pedersen is with the Garvan Institute of Medical Research in Sydney, Australia, Dr. Watt is from St. Vincent’s Institute of Medical Research, Fitzroy, Victoria, Australia. All others are with the Royal Melbourne Institute of Technology University (RMIT) in Bundoora, Victoria, Australia.

A fuller audio interview with Dr. Hawley is available in Episode 11 of the APS podcast, Life Lines, at www.lifelines.tv. The show also includes an interview with Dr. Stanley Schultz, whose physiological discovery of how sugar is transported in the gut led to the development of oral rehydration therapy and sports drinks such as Gatorade and Hi-5.

Caffeine aids carbohydrate uptake  

It is already established that consuming carbohydrate and caffeine prior to and during exercise improves a variety of athletic performances. This is the first study to show that caffeine combined with carbohydrates following exercise can help refuel the muscle faster.

“If you have 66% more fuel for the next day’s training or competition, there is absolutely no question you will go farther or faster,” said Dr. Hawley, the study’s senior author. Caffeine is present in common foods and beverages, including coffee, tea, chocolate and cola drinks.

The study was conducted on seven well-trained endurance cyclists who participated in four sessions. The participants first rode a cycle ergometer until exhaustion, and then consumed a low-carbohydrate dinner before going home. This exercise bout was designed to reduce the athletes’ muscle glycogen stores prior to the experimental trial the next day.

The athletes did not eat again until they returned to the lab the next day for the second session when they again cycled until exhaustion. They then ingested a drink that contained carbohydrate alone or carbohydrate plus caffeine and rested in the laboratory for four hours. During this post-exercise rest time, the researchers took several muscle biopsies and multiple blood samples to measure the amount of glycogen being replenished in the muscle, along with the concentrations of glucose-regulating metabolites and hormones in the blood, including glucose and insulin.

The entire two-session process was repeated 7-10 days later. The only difference was that this time, the athletes drank the beverage that they had not consumed in the previous trial. (That is, if they drank the carbohydrate alone in the first trial, they drank the carbohydrate plus caffeine in the second trial, and vice versa.)

The drinks looked, smelled and tasted the same and both contained the same amount of carbohydrate. Neither the researchers nor the cyclists knew which regimen they were receiving, making it a double-blind, placebo-controlled experiment.

Glucose and insulin levels higher with caffeine ingestion
The researchers found the following:  
  • one hour after exercise, muscle glycogen levels had replenished to the same extent whether or not the athlete had the drink containing carbohydrate and caffeine or carbohydrate only
  • four hours after exercise, the drink containing caffeine resulted in 66% higher glycogen levels compared to the carbohydrate-only drink
  • throughout the four-hour recovery period, the caffeinated drink resulted in higher levels of blood glucose and plasma insulin
  • several signaling proteins believed to play a role in glucose transport into the muscle were elevated to a greater extent after the athletes ingested the carbohydrate-plus-caffeine drink, compared to the carbohydrate-only drink

 Dr. Hawley said it is not yet clear how caffeine aids in facilitating glucose uptake from the blood into the muscles. However, the higher circulating blood glucose and plasma insulin levels were likely to be a factor. In addition, caffeine may increase the activity of several signaling enzymes, including the calcium-dependent protein kinase and protein kinase B (also called Akt), which have roles in muscle glucose uptake during and after exercise.

Lower dose is next step  

In this study, the researchers used a high dose of caffeine to establish that it could help the muscles convert ingested carbohydrates to glycogen more rapidly. However, because caffeine can have potentially negative effects, such as disturbing sleep or causing jitteriness, the next step is to determine whether smaller doses could accomplish the same goal.

Hawley pointed out that the responses to caffeine ingestion vary widely between individuals. Indeed, while several of the athletes in the study said they had a difficult time sleeping the night after the trial in which they ingested caffeine (8 mg per kilogram of body weight, the equivalent of drinking 5-6 cups of strong coffee), several others fell asleep during the recovery period and reported no adverse effects.

Athletes who want to incorporate caffeine into their workouts should experiment during training sessions well in advance of an important competition to find out what works for them.

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Article adapted by MD Sports from original press release.
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Contact: Christine Guilfoy
American Physiological Society

Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS) has been an integral part of this scientific discovery process since it was established in 1887.

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