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.

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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.

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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.”

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