Fitness
Limiting mealtimes may increase your motivation for exercise
Limiting access to food in mice increases levels of the hormone, ghrelin, which may also increase motivation to exercise, according to a study published in the Journal of Endocrinology. The study suggests that a surge in levels of appetite-promoting hormone, ghrelin, after a period of fasting prompted mice to initiate voluntary exercise. These novel findings indicate that better diet control, for example limiting food intake to mealtimes or fasting intermittently, could help overweight people maintain a more effective exercise routine, lose weight and avoid debilitating complications such as diabetes and heart disease.
Obesity is a costly and growing, global health epidemic that needs more effective intervention strategies to avoid serious complications including heart disease and diabetes. Food restriction and regular exercise are the two main cost-effective strategies to prevent and treat obesity; however the condition is often associated with a sedentary lifestyle and bad eating habits, such as snacking and binge eating. Consequently, adhering to a regular exercise regime can be difficult due to an inability to exercise for a prolonged period or a lack of motivation. Ghrelin, often referred to as the 'hunger hormone', stimulates appetite through actions on the brain reward circuitry that increase motivation to eat. It has also been reported to be essential for endurance exercise by increasing metabolism to meet the energy demands of prolonged exercise. Although previous studies have suggested a relationship between ghrelin and exercise, it is not known whether ghrelin levels have a direct effect on motivation to exercise.
In this study, Dr Yuji Tajiri and colleagues from Kurume University School of Medicine in Japan, investigated the relationship between exercise and ghrelin levels in mice. Food intake and wheel-running activity were compared in mice given free access to food and those fed only twice a day for a limited time. Although both groups ate a similar amount of food, the restricted mice ran significantly more. Mice genetically altered to have no ghrelin and on the restricted feeding diet ran less than the mice given free access, however, this could be reversed by administering ghrelin. Furthermore, mice given free access to food and given ghrelin also ran significantly more. These findings suggest that ghrelin may play an important role in the motivation for both feeding and exercise, in response to restricted eating plans.
Dr Tajiri comments, "Our findings suggest that hunger, which promotes ghrelin production, may also be involved in increasing motivation for voluntary exercise, when feeding is limited. Therefore, maintaining a healthy eating routine, with regular mealtimes or fasting, could also encourage motivation for exercise in overweight people."
However, Dr Tajiri cautions. "These findings and previous reports are based on animal studies; so much more work is needed to confirm that this ghrelin response is also present in people. If it can be established in clinical practice, it not only opens up new cost-effective diet and exercise strategies but may also indicate a new therapeutic application for ghrelin-mimicking drugs."
Dr Tajiri and his team now plan to carry out more experiments to confirm these findings in humans, to further characterise how ghrelin acts in the brain to produce motivation to eat or exercise and to explore any potential real-world, clinical benefits for the treatment and prevention of obesity.
COVID-19 coronavirus epidemic has a natural origin
The novel SARS-CoV-2 coronavirus that emerged in the city of Wuhan, China, last year and has since caused a large scale COVID-19 epidemic and spread to more than 70 other countries is the product of natural evolution, according to findings published today in the journal Nature Medicine.
The analysis of public genome sequence data from SARS-CoV-2 and related viruses found no evidence that the virus was made in a laboratory or otherwise engineered.
"By comparing the available genome sequence data for known coronavirus strains, we can firmly determine that SARS-CoV-2 originated through natural processes," said Kristian Andersen, PhD, an associate professor of immunology and microbiology at Scripps Research and corresponding author on the paper.
In addition to Andersen, authors on the paper, "The proximal origin of SARS-CoV-2," include Robert F. Garry, of Tulane University; Edward Holmes, of the University of Sydney; Andrew Rambaut, of University of Edinburgh; W. Ian Lipkin, of Columbia University.
Coronaviruses are a large family of viruses that can cause illnesses ranging widely in severity. The first known severe illness caused by a coronavirus emerged with the 2003 Severe Acute Respiratory Syndrome (SARS) epidemic in China. A second outbreak of severe illness began in 2012 in Saudi Arabia with the Middle East Respiratory Syndrome (MERS).
On December 31 of last year, Chinese authorities alerted the World Health Organization of an outbreak of a novel strain of coronavirus causing severe illness, which was subsequently named SARS-CoV-2. As of February 20, 2020, nearly 167,500 COVID-19 cases have been documented, although many more mild cases have likely gone undiagnosed. The virus has killed over 6,600 people.
Shortly after the epidemic began, Chinese scientists sequenced the genome of SARS-CoV-2 and made the data available to researchers worldwide. The resulting genomic sequence data has shown that Chinese authorities rapidly detected the epidemic and that the number of COVID-19 cases have been increasing because of human to human transmission after a single introduction into the human population. Andersen and collaborators at several other research institutions used this sequencing data to explore the origins and evolution of SARS-CoV-2 by focusing in on several tell-tale features of the virus.
The scientists analyzed the genetic template for spike proteins, armatures on the outside of the virus that it uses to grab and penetrate the outer walls of human and animal cells. More specifically, they focused on two important features of the spike protein: the receptor-binding domain (RBD), a kind of grappling hook that grips onto host cells, and the cleavage site, a molecular can opener that allows the virus to crack open and enter host cells.
Evidence for natural evolution
The scientists found that the RBD portion of the SARS-CoV-2 spike proteins had evolved to effectively target a molecular feature on the outside of human cells called ACE2, a receptor involved in regulating blood pressure. The SARS-CoV-2 spike protein was so effective at binding the human cells, in fact, that the scientists concluded it was the result of natural selection and not the product of genetic engineering.
This evidence for natural evolution was supported by data on SARS-CoV-2's backbone -- its overall molecular structure. If someone were seeking to engineer a new coronavirus as a pathogen, they would have constructed it from the backbone of a virus known to cause illness. But the scientists found that the SARS-CoV-2 backbone differed substantially from those of already known coronaviruses and mostly resembled related viruses found in bats and pangolins.
"These two features of the virus, the mutations in the RBD portion of the spike protein and its distinct backbone, rules out laboratory manipulation as a potential origin for SARS-CoV-2" said Andersen.
Josie Golding, PhD, epidemics lead at UK-based Wellcome Trust, said the findings by Andersen and his colleagues are "crucially important to bring an evidence-based view to the rumors that have been circulating about the origins of the virus (SARS-CoV-2) causing COVID-19."
"They conclude that the virus is the product of natural evolution," Goulding adds, "ending any speculation about deliberate genetic engineering."
Possible origins of the virus
Based on their genomic sequencing analysis, Andersen and his collaborators concluded that the most likely origins for SARS-CoV-2 followed one of two possible scenarios.
In one scenario, the virus evolved to its current pathogenic state through natural selection in a non-human host and then jumped to humans. This is how previous coronavirus outbreaks have emerged, with humans contracting the virus after direct exposure to civets (SARS) and camels (MERS). The researchers proposed bats as the most likely reservoir for SARS-CoV-2 as it is very similar to a bat coronavirus. There are no documented cases of direct bat-human transmission, however, suggesting that an intermediate host was likely involved between bats and humans.
In this scenario, both of the distinctive features of SARS-CoV-2's spike protein -- the RBD portion that binds to cells and the cleavage site that opens the virus up -- would have evolved to their current state prior to entering humans. In this case, the current epidemic would probably have emerged rapidly as soon as humans were infected, as the virus would have already evolved the features that make it pathogenic and able to spread between people.
In the other proposed scenario, a non-pathogenic version of the virus jumped from an animal host into humans and then evolved to its current pathogenic state within the human population. For instance, some coronaviruses from pangolins, armadillo-like mammals found in Asia and Africa, have an RBD structure very similar to that of SARS-CoV-2. A coronavirus from a pangolin could possibly have been transmitted to a human, either directly or through an intermediary host such as civets or ferrets.
Then the other distinct spike protein characteristic of SARS-CoV-2, the cleavage site, could have evolved within a human host, possibly via limited undetected circulation in the human population prior to the beginning of the epidemic. The researchers found that the SARS-CoV-2 cleavage site, appears similar to the cleavage sites of strains of bird flu that has been shown to transmit easily between people. SARS-CoV-2 could have evolved such a virulent cleavage site in human cells and soon kicked off the current epidemic, as the coronavirus would possibly have become far more capable of spreading between people.
Study co-author Andrew Rambaut cautioned that it is difficult if not impossible to know at this point which of the scenarios is most likely. If the SARS-CoV-2 entered humans in its current pathogenic form from an animal source, it raises the probability of future outbreaks, as the illness-causing strain of the virus could still be circulating in the animal population and might once again jump into humans. The chances are lower of a non-pathogenic coronavirus entering the human population and then evolving properties similar to SARS-CoV-2.
Funding for the research was provided by the US National Institutes of Health, the Pew Charitable Trusts, the Wellcome Trust, the European Research Council, and an ARC Australian Laureate Fellowship.
''Good health is the key to successful life''
The main components leading to good health
- Balanced Diet
- Burning of consumed calories efficiently and effectively
Inspite of having a lot of knowledge about a balanced diet the knowledge of its consumption is lacking in our society. My aim of writing this blog is
- To create awareness in our youth about its importance.
- Help them in gaining professional skills to pursue their career
People always want to groom themselves and look attractive and eye-catching, therefore they need to go to a fitness centre on a regular basis.Normally in the busy life routine and stress of the society make it quite hard for the person to maintain themselves. In the changing time, there is a quite high level of need of fitness centre to stress release.
- To create awareness in our youth about its importance.
- Save Money
- Enhance your stamina and life expectancy
- Reduce risk f injury
- Improve your quality of life
- Stay active
- Improve your health
- Help them in gaining professional skills to pursue their career
To get into the habit of a morning workout, start with gentle movements that yield big results
Youth in third world countries aré unable to identify their strengths and interests in sports because of the eductional norms are not encouraging and no counselling and guidance is provided at usually right time. We aim to provide a platform where they will identify their interests and get a chance to interact with people sharing their interests and also having life time experience in fields like athletics
martial arts
body building and a lot more.
My experiences will be a plus point too as I am in continuous contact with mates and instructors of UFC -the best international gym having state of the art equipment and most experienced instructors who not only help you identify your weaknesses but also ways to use them to gain strength in required field of interest
'' The ultimate measure of a man is not when he stands in moments of comfort and convenience, but when he stands at times of challenge and cotrooversy.''
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