Coffee May Improve Athletic Endurance Performance

 

Posted on December 18, 2015 by Stone Hearth News

 

Newswise — Athens, Ga. – The caffeine in a morning cup of coffee could help improve athletic endurance, according to a new University of Georgia review study.

Authored by Simon Higgins, a third-year doctoral student in kinesiology in the College of Education, the study was published in this month’s issue of the International Journal of Sport Nutrition and Exercise Metabolism.

To research the issue, Higgins reviewed more than 600 scholarly articles and screened them for those that focused only on caffeinated-coffee conditions, measured the caffeine dose and measured an endurance performance. Of these, nine randomized control trials specifically used coffee to improve endurance.

“Previous research has focused on caffeine itself as an aid to improve endurance,” Higgins said. “Coffee is a popular source of caffeine, so this paper looked at the research surrounding its ergogenic benefits.”

Looking at the nine trials, Higgins found that between 3 and 7 milligrams per kilogram of body weight of caffeine from coffee increased endurance performance by an average of 24 percent. The amount of caffeine in a cup of coffee can vary from 75 mg to more than 150, depending on the variety and how it’s roasted and brewed.

“This is helpful for athletes because coffee is a naturally occurring compound,” Higgins said. “There’s the potential that getting your caffeine by drinking coffee has similar endurance benefits as taking caffeine pills.”

In the nine trials, participants either cycled or ran after drinking coffee. They then exercised vigorously and the results were measured. In a majority of cases, endurance was noticeably improved after the use of coffee.

When researching the effects of caffeine from coffee, Higgins found two important discoveries: that caffeine from coffee has ergogenic benefits—that it enhances physical performance—and that more research is needed on the use of caffeine from coffee versus pure caffeine use.

“While there is a lack of high-quality research on coffee as a source of caffeine, there is an abundance of research on pure caffeine,” he said. “It’s surprising how little we know about caffeine from coffee when its endurance effects could be just as beneficial as pure caffeine.”

Higgins said that coffee shouldn’t be dismissed as less beneficial for endurance. He found that coffee appears to be just as helpful as taking caffeine in the form of powder or tablets.

“There’s a perception that coffee won’t give you the same benefits as pure caffeine,” he said. “New research could mean that athletes could have a cup of coffee versus taking a pill.”

Higgins says that more research is needed before giving official recommendations to athletes, especially since the amount of caffeine in a cup of coffee can vary depending on how it’s prepared.
“There is a caveat to athletes using coffee: Be careful because you don’t know how much caffeine is in some coffee, especially when it’s prepared by someone else,” he said. “Athletes should run their caffeine use through their sports dietician as the NCAA lists it as a banned substance.”

Co-authors of the paper are Richard D. Lewis, UGA Foundation Professor in Family and Consumer Sciences, and Chad R. Straight, previously a graduate student at the University of Georgia.
An abstract of the study, “The Effects of Pre-Exercise Caffeinated-Coffee Ingestion on Endurance Performance: An Evidence-Based Review,” is available at http://www.ncbi.nlm.nih.gov/pubmed/26568580.

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Early-life exercise alters gut microbes, promotes healthy brain and metabolism

 

Posted on December 29, 2015 by Stone Hearth News

 

 

The human gut harbors a teeming menagerie of over 100 trillion microorganisms, and researchers at the University of Colorado Boulder have discovered that exercising early in life can alter that microbial community for the better, promoting healthier brain and metabolic activity over the course of a lifetime.

The research, which was recently published in the journal Immunology and Cell Biology, indicates that there may be a window of opportunity during early human development to optimize the chances of better lifelong health.

“Exercise affects many aspects of health, both metabolic and mental, and people are only now starting to look at the plasticity of these gut microbes,” said Monika Fleshner, a professor in CU-Boulder’s Department of Integrative Physiology and the senior author of the new study. “That is one of the novel aspects of this research.”

Microbes take up residence within human intestines shortly after birth and are vital to the development of the immune system and various neural functions. These microbes can add as many 5 million genes to a person’s overall genetic profile and thus have tremendous power to influence aspects of human physiology.

While this diverse microbial community remains somewhat malleable throughout adult life and can be influenced by environmental factors such as diet and sleep patterns, the researchers found that gut microorganisms are especially ‘plastic’ at a young age.

The study found that juvenile rats who voluntarily exercised every day developed a more beneficial microbial structure, including the expansion of probiotic bacterial species in their gut compared to both their sedentary counterparts and adult rats, even when the adult rats exercised as well.

The researchers have not, as of yet, pinpointed an exact age range when the gut microbe community is likeliest to change, but the preliminary findings indicate that earlier is better.

A robust, healthy community of gut microbes also appears to promote healthy brain function and provide anti-depressant effects, Fleshner said. Previous research has shown that the human brain responds to microbial signals from the gut, though the exact communication methods are still under investigation.

“Future research on this microbial ecosystem will hone in on how these microbes influence brain function in a long-lasting way,” said Agniezka Mika, a graduate researcher in CU-Boulder’s Department of Integrative Physiology and the lead author of the new study.

Going forward, the researchers also plan to explore novel means of encouraging positive gut microbe plasticity in adults, who tend to have stable microbial communities that are more resistant to change.

###

 

The National Institutes of Health (NIH) supported this research.
Source

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Eating at the wrong time impairs learning and memory

 

Posted on December 23, 2015 by Stone Hearth News

 

An occasional late-night raid on turkey leftovers might be harmless but new research with mice suggests that making a habit of it could alter brain physiology.

Eating at times normally reserved for sleep causes a deficiency in the type of learning and memory controlled by the hippocampal area of the brain, according to findings in the journal eLife.
Researchers from the Semel Institute in the David Geffen School of Medicine at University of California, Los Angeles (UCLA) became interested in the cognitive effects of eating at inappropriate hours because it is already known to have an impact on metabolic health, for example leading to a pre-diabetic state.

“We have provided the first evidence that taking regular meals at the wrong time of day has far-reaching effects for learning and memory,” says first author Dawn Loh from the UCLA Laboratory of Circadian and Sleep Medicine.

“Since many people find themselves working or playing during times when they’d normally be asleep, it is important to know that this could dull some of the functions of the brain.”
The researchers stress that their findings have not been confirmed in humans, but highlight the fact that shift workers have been shown to perform less well on cognitive tests.

The current study shows that some learned behaviours are more affected than others. The team tested the ability of mice to recognise a novel object. Mice regularly fed during their sleep-time were significantly less able to recall the object. Long-term memory was also dramatically reduced, demonstrated during a fear conditioning experiment.

Both long-term memory and the ability to recognise a novel object are governed by the hippocampus. The hippocampus plays an important role in our ability to associate senses and emotional experiences with memory and our ability to organise and store new memories.

During an experience, nerve impulses are activated along specific pathways and, if we repeat the experience, the same pathways increase in strength. However, this effect was reduced when food was made available to mice during a six-hour window in the middle of their normal sleep time instead of a six-hour daytime window when the mice were active.

Some genes involved in both the circadian clock and in learning and memory are regulated by a protein called CREB (cAMP response element-binding protein). When CREB is less active, it decreases memory, and may play a role in the onset of Alzheimer’s disease. In the mice fed at the wrong time, the total activity of CREB throughout the hippocampus was significantly reduced, with the strongest effects in the day.

However, the master pacemaker of the circadian system, the suprachiasmatic nucleus located in the hypothalamus, is unaffected. This leads to desynchrony between the clocks in the different brain regions (misalignment), which the authors suggest underlies the memory impairment.
“Modern schedules can lead us to eat around the clock so it is important to understand how the timing of food can impact cogitation” says Professor Christopher Colwell from the Department of Psychiatry and Biobehavioral Sciences at UCLA.

“For the first time, we have shown that simply adjusting the time when food is made available alters the molecular clock in the hippocampus and can alter the cognitive performance of mice.”

Eating at the wrong time also disrupted sleep patterns. The inappropriate feeding schedule resulted in the loss of the normal day/night difference in the amount of sleep although the total time spent asleep over 24 hours was not changed. Sleep became fragmented, with the mice catching up on sleep by grabbing more short naps throughout the day and night.

###

 

Reference

The paper ‘Misaligned feeding impairs memories’ can be freely accessed online at http://dx.doi.org/10.7554/eLife.09460. Contents, including text, figures, and data, are free to re¬use under a CC BY 4.0 license.
About eLife

eLife is a unique collaboration between the funders and practitioners of research to improve the way important research is selected, presented, and shared. eLife publishes outstanding works across the life sciences and biomedicine — from basic biological research to applied, translational, and clinical studies. eLife is supported by the Howard Hughes Medical Institute, the Max Planck Society, and the Wellcome Trust. Learn more at elifesciences.org

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How different fluids affect hydration: a new study

 

Posted on December 24, 2015 by Stone Hearth News

 

First published December 23, 2015, doi: 10.3945/​ajcn.115.114769
Am J Clin Nutr
ajcn114769

A randomized trial to assess the potential of different beverages to affect hydration status: development of a beverage hydration index 1

Ronald J Maughan2,*, Phillip Watson2, Philip AA Cordery2, Neil P Walsh3, Samuel J Oliver3, Alberto Dolci3, Nidia Rodriguez-Sanchez4, and Stuart DR Galloway4

Author Affiliations

2School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, United Kingdom;
3School of Sport, Health and Exercise Sciences, Bangor University, Bangor, United Kingdom; and
4School of Sport, University of Stirling, Stirling, United Kingdom

Author Notes

↵1 Supported by a grant from the European Hydration Institute.
↵*To whom correspondence should be addressed. E-mail: r.j.maughan@lboro.ac.uk.

Abstract

Background: The identification of beverages that promote longer-term fluid retention and maintenance of fluid balance is of real clinical and practical benefit in situations in which free access to fluids is limited or when frequent breaks for urination are not desirable. The postingestion diuretic response is likely to be influenced by several beverage characteristics, including the volume ingested, energy density, electrolyte content, and the presence of diuretic agents.

Objective: This study investigated the effects of 13 different commonly consumed drinks on urine output and fluid balance when ingested in a euhydrated state, with a view to establishing a beverage hydration index (BHI), i.e., the volume of urine produced after drinking expressed relative to a standard treatment (still water) for each beverage.

Design: Each subject (n = 72, euhydrated and fasted male subjects) ingested 1 L still water or 1 of 3 other commercially available beverages over a period of 30 min. Urine output was then collected for the subsequent 4 h. The BHI was corrected for the water content of drinks and was calculated as the amount of water retained at 2 h after ingestion relative to that observed after the ingestion of still water.

Results: Total urine masses (mean ± SD) over 4 h were smaller than the still-water control (1337 ± 330 g) after an oral rehydration solution (ORS) (1038 ± 333 g, P < 0.001), full-fat milk (1052 ± 267 g, P < 0.001), and skimmed milk (1049 ± 334 g, P < 0.001). Cumulative urine output at 4 h after ingestion of cola, diet cola, hot tea, iced tea, coffee, lager, orange juice, sparkling water, and a sports drink were not different from the response to water ingestion. The mean BHI at 2 h was 1.54 ± 0.74 for the ORS, 1.50 ± 0.58 for full-fat milk, and 1.58 ± 0.60 for skimmed milk.
Conclusions: BHI may be a useful measure to identify the short-term hydration potential of different beverages when ingested in a euhydrated state. This trial was registered at www.isrctn.com as ISRCTN13014105.

Source

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The impact of yoga on atrial fibrillation: A review of The Yoga My Heart Study.

 

Posted on December 25, 2015 by Stone Hearth News

 

  

J Arrhythm. 2015 Dec;31(6):337-8. doi: 10.1016/j.joa.2015.05.001. Epub 2015 Jun 6.
The impact of yoga on atrial fibrillation: A review of The Yoga My Heart Study.
Deutsch SB1, Krivitsky EL1.

Author information

1University of South Florida Morsani College of Medicine, 1 Tampa General Circle, Tampa, FL 33606, USA.

Abstract

Atrial fibrillation is a common arrhythmia affecting thousands of individuals worldwide.
It is a conduction disorder that causes the heart to beat irregularly and rapidly.

There are a few medical approaches to manage this costly health care burden: antiarrhythmics to maintain normal sinus rhythm, beta blockers to achieve rate control while allowing atrial fibrillation to persist, and electro-physiologic intervention for rate and rhythm control.

These treatments can be costly and are not without side effects.

Yoga, an intervention that is available to people worldwide, has shown some promise in combating this widespread heart disorder.

Source

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Brief periods of standing, walking tied to better blood sugar

 

Posted on December 14, 2015 by Stone Hearth News

 

(Reuters Health) – Older women at risk for type 2 diabetes may want to break up prolonged periods of sitting by standing or going for short walks, suggests a new study from the UK.

Researchers found standing up or walking every so often improved blood sugar, or glucose, levels among postmenopausal women at risk for diabetes, compared to those who sat for 7.5 hours.

“We were really interested in seeing whether breaking up that sitting time with standing or walking had a role in breaking up glucose levels throughout the day,” said lead author Joseph Henson, of the University of Leicester.

The study involved 22 overweight postmenopausal women at risk for diabetes, and three possible daily routines. The women were randomly assigned to follow two of the routines on separate days, at least a week apart. Either they would sit for 7.5 hours, or they would break up the time by standing up for five minutes every half hour, or they’d walk for five minutes every half hour.

The women ate a standardized breakfast and lunch, and the researchers then took blood samples throughout the day.

“After eating, there is a big spike in glucose levels,” said Henson. “In those with impaired glucose regulation, they’re not able to bring them back down to normal levels that quickly.”

More


 

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Back pain: Prevention and management in the workplace

 

Posted on November 28, 2015 by Stone Hearth News

 

Best Pract Res Clin Rheumatol. 2015 Jun;29(3):483-94. doi: 10.1016/j.berh.2015.04.028. Epub 2015 May 31.

Back pain: Prevention and management in the workplace.

Schaafsma FG1, Anema JR2, van der Beek AJ3.

Author information

1Department of Public and Occupational Health, EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands; Research Centre for Insurance Medicine, Collaboration Between AMC-UMCG-UWV-VUmc, Amsterdam, The Netherlands. Electronic address: f.schaafsma@vumc.nl.
2Department of Public and Occupational Health, EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands; Research Centre for Insurance Medicine, Collaboration Between AMC-UMCG-UWV-VUmc, Amsterdam, The Netherlands.
3Department of Public and Occupational Health, EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands; Research Centre for Insurance Medicine, Collaboration Between AMC-UMCG-UWV-VUmc, Amsterdam, The Netherlands; Body@Work, Research Center Physical Activity, Work and Health, TNO-VU University Medical Center, Amsterdam, The Netherlands.

Abstract

Despite all the efforts in studying work-related risk factors for low back pain (LBP), interventions targeting these risk factors to prevent LBP have no proven cost-effectiveness. Even with adequate implementation strategies for these interventions on group level, these did not result in the reduction of incident LBP. Physical exercise, however, does have a primary preventive effect on LBP.
For secondary prevention, it seems that there are more opportunities to cost-effectively intervene in reducing the risk of long-term sickness absence due to LBP.
Starting at the earliest moment possible with proper assessment of risk factors for long-term sickness absence related to the individual, the underlying mechanisms of the LBP, and also factors related to the workplace by a well-trained clinician, may increase the potential of effective return to work (RTW) management.
More research on how to overcome barriers in the uptake of these effective interventions in relation to policy-specific environments, and with regard to proper financing of RTW management is necessary.
Source

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Even if they exercise, heart disease patients who sit a lot have worse health

 

Posted on November 29, 2015 by Stone Hearth News

 

Ottawa, November 25, 2015 – Patients with heart disease who sit a lot have worse health even if they exercise, reveals research from the University of Ottawa Heart Institute, and published today in the European Journal of Cardiovascular Prevention.1
“Get up and move every 30 minutes to improve health.”
“Limiting the amount of time we spend sitting may be as important as the amount we exercise,” said lead author Dr Stephanie Prince, post-doctorate fellow in the Division of Prevention and Rehabilitation, University of Ottawa Heart Institute. “Sitting, watching TV, working at a computer and driving in a car are all sedentary behaviours and we need to take breaks from them.”
Previous research has shown that being sedentary increases the risk of cardiovascular disease but until now its effect on patients with established heart disease was unknown.
The current study investigated levels of sedentary behaviour and the effect on health in 278 patients with coronary artery disease. The patients had been through a cardiac rehabilitation programme which taught them how to improve their levels of exercise in the long term.
Patients wore an activity monitor during their waking hours for nine days. The monitors allowed the researchers to measure how long patients spent being sedentary, or doing light, moderate or vigorous levels of physical activity.
The researchers also assessed various markers of health including body mass index (BMI, in kg/m2) and cardiorespiratory fitness. Next they looked at whether the amount of time a person spent being sedentary (which was mainly sitting) was related to these markers of health.
The researchers found that patients with coronary artery disease spent an average of eight hours each day being sedentary. “This was surprising given that they had taken classes on how to exercise more,” said Dr Prince. “We assumed they would be less sedentary but they spent the majority of their day sitting.”
Men spent more time sitting than women – an average of one hour more each day. This was primarily because women tended to do more light intensity movement – things like light housework, walking to the end of the drive, or running errands.
Dr Prince said: “Women with coronary artery disease spend less time sitting for long periods but we need to do more research to understand why. There is some research from the past which suggests that at around the age of 60 men become more sedentary than women and may watch more TV.”
The researchers found that patients who sat more had a higher BMI. They also had lower cardiorespiratory fitness, which was assessed using VO2 peak. This is the maximum rate at which the heart, lungs and muscles use oxygen during an exercise test (also called aerobic capacity).
“These relationships remained even when we controlled for an individual’s age, gender or physical activity levels,” said Dr Prince. “In other words, people who sat for longer periods were heavier and less fit regardless of how much they exercised.”
Practical tips to get moving:

• Get up and move every 30 minutes
• Stand up during TV commercials or, even better, do light exercises while watching TV
• Set a timer and take regular breaks from your desk
• Take lunch breaks outside instead of in front of the computer
• Go to bed instead of sitting in front of the TV and get the benefits of sleeping
• Monitor your activity patterns to find out when you are most sedentary.

Dr Prince emphasized that sitting less was not a replacement for exercise. “It’s important to limit prolonged bouts of sitting and in addition to be physically active,” she said. “Sedentary time may be another area of focus for cardiac rehabilitation programmes along with exercise.”
Source

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tryouts for THE UPcOMINg SEASON OF The Ultimate Fighter® CURRENTLY open to three weight classes

 

 

 

tryouts for THE UPcOMINg SEASON OF

The Ultimate Fighter^® CURRENTLY open to three weight classes

 

WOMEN’s STRAWWEIGHT AND BANTAMWEIGHT

Men’s LIGHT HEAVYWEIGHT

 

Tryouts to be held in Las Vegas on Monday, December 14

 

Las Vegas, Nevada – UFC^® announces tryouts for the upcoming season of its long-running successful reality series, The Ultimate Fighter^®, at Red Rock Casino in Las Vegas, Nev. on Monday, December 14. This season’s tryouts are currently open to both 115- and 135-pound women, as well as 205-pound men, with winning professional records.

 

This season of The Ultimate Fighter will begin filming in January and is scheduled to premiere on FS1 in April 2016.

 

Candidates must be between the ages of 21 and 34 years of age, have the legal ability to live and work in the United States, and have professional Mixed Martial Arts (MMA) fight experience – holding a winning record with a minimum of three professional fights (with verifiable records). Applications, which should be completed and brought to the tryouts, can be found online at http://www.ufc.com/TUF23. Tryout details are provided below:

 

Where:

Red Rock Casino

11011 W. Charleston Blvd.

Las Vegas, Nevada 89135

 

When:

Monday, December 14, 2015

Registration begins at 8:00 a.m. PT

 

Fighters will be required to grapple & hit pads. Please bring appropriate gear.

 

*Applicants will be notified at the end of the day if they have been selected to move on in the casting process. If selected, applicants must be prepared to stay in Las Vegas until Saturday, December 19, 2015.

 

Questions can be directed to: TUFcasting@ufc.com

    

The Ultimate Fighter^®, which debuted in 2005, has launched the careers of some of the UFC’s most recognizable names and successful athletes. The series has produced champions such as Forrest Griffin, Rashad Evans, TJ Dillashaw, Carla Esparza and Matt Serra, as well as season winners Michael Bisping, Ryan Bader, Nate Diaz and John Dodson.

 

For more show information, bios, videos and photos, visit ultimatefighter.com and don’t forget to follow us on Twitter @UltimateFighter or on Facebook.com/TUF.

 

###

 

About UFC^®

UFC^® is the premier mixed martial arts (MMA) organization and largest Pay-Per-View event provider in the world. Headquartered in Las Vegas with offices in London, Toronto, Singapore and Sao Paulo, UFC produces more than 40 live events annually that consistently sell out some of the most prestigious arenas around the globe. UFC programming is broadcast in 158 countries and territories to over one billion TV households worldwide in 21 different languages. The UFC has a multi-year broadcast agreement with FOX in the U.S., which annually includes four live events broadcast on the FOX network, as well as The Ultimate Fighter^® reality television show and thousands of hours of programming on FOX Sports 1 and FOX Sports 2. In 2014, UFC launched UFC FIGHT PASS^®, a digital subscription service that is available throughout the world with exclusive live events, thousands of fights on-demand and original content. The UFC organization also licenses over 100 UFC GYM^® locations, and owns UFC.TV^® (offering live event broadcasts and video on-demand around the world), UFC FIT^® (an in-home fitness and nutrition program), UFC Magazine, and has a videogame franchise with EA SPORTS, UFC Fight Club^®, UFC Fan Expo^®, UFC branded apparel, DVDs and Blu-rays and Topps Trading Cards. For more information, visit UFC.com and follow UFC at Facebook.com/UFC, Twitter and Instagram: @UFC.

 

Carbohydrate Dependence During Prolonged, Intense Endurance Exercise

 

Posted on November 14, 2015 by Stone Hearth News

 

 

Sports Med. 2015 Nov 9. [Epub ahead of print]

Carbohydrate Dependence During Prolonged, Intense Endurance Exercise.
Hawley JA1,2, Leckey JJ3.

Author information

1The Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Locked Bag 4115, Fitzroy, VIC, 3065, Australia. John.hawley@acu.edu.au.
2Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, UK. John.hawley@acu.edu.au.
3The Mary MacKillop Institute for Health Research, Centre for Exercise and Nutrition, Australian Catholic University, Locked Bag 4115, Fitzroy, VIC, 3065, Australia.

Abstract

A major goal of training to improve the performance of prolonged, continuous, endurance events lasting up to 3 h is to promote a range of physiological and metabolic adaptations that permit an athlete to work at both higher absolute and relative power outputs/speeds and delay the onset of fatigue (i.e., a decline in exercise intensity).
To meet these goals, competitive endurance athletes undertake a prodigious volume of training, with a large proportion performed at intensities that are close to or faster than race pace and highly dependent on carbohydrate (CHO)-based fuels to sustain rates of muscle energy production [i.e., match rates of adenosine triphosphate (ATP) hydrolysis with rates of resynthesis].
Consequently, to sustain muscle energy reserves and meet the daily demands of training sessions, competitive athletes freely select CHO-rich diets.
Despite renewed interest in high-fat, low-CHO diets for endurance sport, fat-rich diets do not improve training capacity or performance, but directly impair rates of muscle glycogenolysis and energy flux, limiting high-intensity ATP production.
When highly trained athletes compete in endurance events lasting up to 3 h, CHO-, not fat-based fuels are the predominant fuel for the working muscles and CHO, not fat, availability becomes rate limiting for performance.

  

Source

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Re-Examining High-Fat Diets for Sports Performance

 

Posted on November 14, 2015 by Stone Hearth News

 

Sports Med. 2015 Nov 9. [Epub ahead of print]
Re-Examining High-Fat Diets for Sports Performance: Did We Call the ‘Nail in the Coffin’ Too Soon?

Burke LM1,2.

Author information

1Sports Nutrition, Australian Institute of Sport, Canberra, ACT, Australia. louise.burke@ausport.gov.au.
2Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia. louise.burke@ausport.gov.au.

Abstract

During the period 1985-2005, studies examined the proposal that adaptation to a low-carbohydrate (60 % energy) diet (LCHF) to increase muscle fat utilization during exercise could enhance performance in trained individuals by reducing reliance on muscle glycogen.

As little as 5 days of training with LCHF retools the muscle to enhance fat-burning capacity with robust changes that persist despite acute strategies to restore carbohydrate availability (e.g., glycogen supercompensation, carbohydrate intake during exercise).

Furthermore, a 2- to 3-week exposure to minimal carbohydrate (<20 g/day) intake achieves adaptation to high blood ketone concentrations.

However, the failure to detect clear performance benefits during endurance/ultra-endurance protocols, combined with evidence of impaired performance of high-intensity exercise via a down-regulation of carbohydrate metabolism led this author to dismiss the use of such fat-adaptation strategies by competitive athletes in conventional sports.

Recent re-emergence of interest in LCHF diets, coupled with anecdotes of improved performance by sportspeople who follow them, has created a need to re-examine the potential benefits of this eating style.

Unfortunately, the absence of new data prevents a different conclusion from being made.
Notwithstanding the outcomes of future research, there is a need for better recognition of current sports nutrition guidelines that promote an individualized and periodized approach to fuel availability during training, allowing the athlete to prepare for competition performance with metabolic flexibility and optimal utilization of all muscle substrates.

Nevertheless, there may be a few scenarios where LCHF diets are of benefit, or at least are not detrimental, for sports performance.

Source

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Effects of Exercise on Sleep Among Young Women With Generalized Anxiety Disorder

 

Posted on November 16, 2015 by Stone Hearth News

 

Ment Health Phys Act. 2015 Oct 1;9:59-66.

Effects of Exercise on Sleep Among Young Women With Generalized Anxiety Disorder.

Herring MP1, Kline CE2, O’Connor PJ3.

Author information

1Department of Physical Education and Sport Sciences, PESS1045, University of Limerick, Limerick, Ireland ; Health Research Institute, University of Limerick, Limerick, Ireland.
2Department of Psychiatry, University of Pittsburgh, 3811 O’Hara St., Pittsburgh, PA 15213.
3Department of Kinesiology, The University of Georgia, 330 River Road, Athens, GA 30602.

Abstract

STATEMENT OF THE PROBLEM:

Generalized Anxiety Disorder (GAD) and disturbed sleep are prevalent, debilitating, and frequently comorbid problems for which successful treatment remains limited. Exercise can promote sleep but whether it does among GAD patients is unknown.

METHODS:

Thirty sedentary women (18-37y) with a primary DSM-IV diagnosis of GAD were randomized to six weeks of resistance (RET) or aerobic exercise training (AET), or waitlist (WL). RET and AET involved twice-weekly sessions of either lower-body weightlifting or leg cycling matched on multiple features of exercise. Outcomes included total sleep time (TST), lights out time, awakening out of bed time, time in bed (TIB), sleep onset latency (SOL), wakefulness after sleep onset, and sleep efficiency. Hedges’ d effect sizes and 95% confidence intervals were calculated for each exercise condition compared to WL. Regression examined baseline associations between anxiety and sleep and associated change.

RESULTS:

Twenty-two of 26 participants reported poor baseline sleep (Pittsburgh Sleep Quality Index >5). RET significantly decreased weekend TIB (d=-1.79; [-2.89, -0.70]) and SOL (d=-1.30; [-2.32, -0.28]), and significantly increased weekend sleep efficiency (d=1.30; [0.29,2.32]). AET significantly reduced weekend TIB (d=-1.13; [-2.16, -0.11]) and SOL (d=-1.08; [-2.09, -0.06]). Reduced GAD clinical severity rating was significantly associated with improved weekend sleep efficiency among RET (t 6=-3.48, p≤0.013).

CONCLUSIONS:

Short-term exercise training improves sleep outcomes among GAD patients, especially for RET and weekend sleep. Findings suggest improved sleep may be associated with reduced clinical severity among GAD patients.

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Fitter legs linked to a ‘fitter’ brain

 

Posted on November 10, 2015 by Stone Hearth News

 

Researchers at King’s College London have found that muscle fitness as measured by power in the legs is strongly associated with an improved rate of ageing in the brain.

The findings, published in Gerontology, suggest that simple interventions, such as increased levels of walking, targeted to improve leg power in the long term may have an impact on healthy cognitive ageing. The research was funded jointly by the NIHR and the Wellcome Trust.

 

Scientists studied a sample of 324 healthy female twins from the TwinsUK volunteer registry over a ten-year period from 1999, measuring various health and lifestyle predictors. Researchers were, therefore, able to control for genetic factors affecting changes in cognitive function.

 

Thinking, learning and memory were measured at both the beginning and end of the study and it was found that leg power was a better predictor of cognitive change than any other lifestyle factors tested. Generally, the twin who had more leg power at the start of the study sustained their cognition better and had fewer brain changes associated with ageing measured after ten years.

 

Previous studies have shown that physical activity can have a beneficial effect on the ageing of the brain with animal studies showing that exercising muscles releases hormones that can encourage nerve cells to grow.

 

The study is thought to be the first that shows a specific link between power (i.e. force and speed) in the lower limbs and cognitive change in a normal, healthy population. As the legs contain the largest muscles they are of particular relevance for muscular fitness and can be exercised easily through various habitual activities such as simply standing or walking.

 

Dr Claire Steves, lead author and Senior Lecturer in Twin Research at King’s College London and King’s College Hospital said: ‘Everyone wants to know how best to keep their brain fit as they age. Identical twins are a useful comparison, as they share many factors, such as genetics and early life, which we can’t change in adulthood.

 

‘It’s compelling to see such differences in cognition and brain structure in identical twins, who had different leg power ten years before. It suggests that simple lifestyle changes to boost our physical activity may help to keep us both mentally and physically healthy.’

 

However, more studies are needed to better understand the relationships between measures of fitness such as leg power or aerobic capacity and brain changes, and the specific cause-and-effect of physical activity on brain structure and cognition. The mechanisms behind this association are not yet clear and could involve other factors such as age-related changes in immune function, blood circulation or nerve signaling.

 

The study only assessed female participants with an average age at baseline of 55 (range 43–73), so further studies would also be needed to establish whether these findings can be generalized to older or male populations.

 

‘Kicking Back Cognitive Ageing: Leg Power Predicts Cognitive Ageing after Ten Years in Older Female Twins’ will be published online in Gerontology on Tuesday 10 November 2015

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For type 2 diabetics, short bursts of high-intensity exercise better than 30 minutes at lower intensity

 

Posted on November 10, 2015 by Stone Hearth News

 

 

ORLANDO, Florida, Nov. 10, 2015 — Short bursts of high-intensity exercise improved cholesterol, blood sugar and weight among Type 2 diabetes patients more than 30 minutes of sustained, lower-intensity exercise, according to research presented at the American Heart Association’s Scientific Sessions 2015.

Researchers found that after three months of high-intensity exercise in 10-minute bursts done three times per day, five days a week, led to an average 0.82 percent decrease in three-month blood sugar patterns compared with just 0.25 percent among those who performed more sustained, lower-intensity exercise also five times per week.

Exercise is known to help reduce cholesterol and weight as well as manage Type 2 diabetes – all risk factors for heart disease. Historically, diabetes management programs have focused primarily on low-intensity, sustained exercise, said lead study author Avinash Pandey, an undergraduate student at the University of Western Ontario in London, Ontario, Canada.

“However, more may be accomplished with short bursts of vigorous exercise, in which patients achieve a higher maximum target heart rate, and may be easier to fit into busy schedules,” Pandey said. “We also found that these 10 minute intervals may be easier to fit into busy schedules, since people randomized to that regimen were more consistent with exercise and ended up doing more exercise per week.”

The study was conducted in 76 patients with Type 2 diabetes (70 percent male, average age 67) who were recruited for the study shortly after their diagnosis. Patients were randomly assigned to either 30 minutes of exercise five days a week at 65 percent of their target heart rate or ten minutes of exercise three times a day, five days a week at 85 percent of their target heart rate.

Burst exercise patients actually ended up exercising more, and overall, experienced a 2.3-fold greater improvement in HbA1c levels as well as a three-fold reduction in body mass index — a measurement of height versus weight. Burst exercise patients also showed greater improvements in their cholesterol levels and stronger cardiac fitness, as measured by stress testing.

Researchers said it’s unclear why shorter bursts of high-intensity exercise would lead to more significant improvements compared with sustained, lower-intensity exercise. One theory is that higher intensity exercise uses energy in a different way, suggests Pandey.

“We are hoping to continue looking at burst exercise and sustained exercise in larger and more diverse patient populations. With further study, burst exercise may become a viable alternative to the current standard of care of low-intensity, sustained exercise for diabetes rehabilitation.”

###

 

Pandey’s co-author is Paul Poirier, M.D., Ph.D. Author disclosures are on the manuscript.
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Chrondroitin Outperforms Celecoxib in Knee Osteoarthritis Study

 

Posted on November 7, 2015 by Stone Hearth News

 

Newswise — SAN FRANCISCO— For the first time, chondroitin sulfate has been more successful than celecoxib in reducing the long-term progression of knee osteoarthritis (OA), according to new research findings presented this week at the American College of Rheumatology Annual Meeting in San Francisco.

Osteoarthritis is a slowly progressive disease in which joint cartilage breaks down. Normally, cartilage on the ends of bones allows smooth, pain-free joint movements. In OA, cartilage becomes thin and irregular, resulting in symptoms of joint pain and stiffness. Grinding or cracking sensations may occur. Joints that are under high stress due to repeated activity or weight bearing are most susceptible to OA. The hips, knees, hands and spine are commonly affected. OA becomes more common with aging.

Chondroitin sulfate, more commonly called chondroitin, has long been the subject of debate when it comes to its usefulness in treating OA. Canadian researchers recently explored how this treatment would affect how OA progresses as well as how it compared to celecoxib (Celebrex) – an often used first-line symptomatic treatment in the disease.

“We felt the present study was necessary in order to establish — using the most recent imaging technology available, quantitative magnetic resonance imaging (qMRI) — whether chondroitin sulfate can truly and effectively reduce the progression of the disease in patients suffering from knee OA,” says lead investigator in the study, Jean-Pierre Pelletier, MD; professor of medicine, University of Montreal; director, Rheumatic Disease Unit, Department of Medicine, University of Montreal School of Medicine; head, Arthritis Division, University of Montreal Hospital Centre (CHUM); head, Chair in Osteoarthritis of the University of Montreal; and director, Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM).

Dr. Pelletier’s team studied 194 people with knee OA and inflammation of the synovial membrane in the knee. The participants were followed for two years and were divided into two groups. The first group took 1200mg (pharmacological preparation) of chondroitin daily, and the second group took 200mg of celecoxib daily.

After the initial evaluation, the researchers followed up with participants again at one and two years to look at a number of factors that would indicate the effectiveness of chondroitin. At all three touchpoints with the participants, the researchers performed MRIs to detect loss of cartilage, changes in bone marrow legions, and thickening of the synovial membrane in the knee. Additionally, patients were evaluated for swelling and fluid in the knee and their overall symptoms — collected through the visual analogue scale and Western Ontario and McMaster Universities Osteoarthritis Index; VAS and WOMAC, respectively.

At both one and two years, the researchers found a better reduction of cartilage loss in the whole knee, and more particularly in the inner half, of the participants on chondroitin when compared to those on celecoxib. Additionally, there was a decrease in synovial membrane thickness in some of the participants on chondroitin, showing far better results for this group. “These findings are most important as they demonstrate that chondroitin, in contrast to celecoxib, can reduce the loss of cartilage, at least in part, by reducing synovial inflammation (thickness),” Dr. Pelletier says.

Both groups noticed a marked reduction in swelling and fluid in the knee in a large number of patients. Both groups also showed a similar effectiveness at reducing OA symptoms over the course of the study. Finally, both groups were able to reduce the amount of acetaminophen they took each day, and both experienced a good tolerance to the treatment they were taking.

“This study demonstrates that both chondroitin sulfate and celecoxib are equally effective at reducing the symptoms of knee OA patients. However, only chondroitin sulfate was found to be capable of slowing down the progression of the disease by reducing the loss of cartilage,” Dr. Pelletier remarks, while also noting further studies to establish the effect of chondroitin in other joints could be of interest.

While these results are promising, Dr. Pelletier would like to point out that the study only used pharmaceutical-grade chondroitin, and results may not be similar for all chondroitin products such as food supplements. Therefore, he recommends that patients consult with their physicians on the use of such treatment for OA.

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