BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: exercise

Exercising in the “Extremes” (Hot or Cold) Does Not Necessarily Lead to Weight Loss. Here’s What Does:

As it has been a trend for years, many believe the claim that exercising in cold or hot temperatures will cause you to burn more calories, leading to weight loss. Although many believe this, it is not actually true nor an efficient way to lose weight. 

First, let me take you through how humans burn calories. The most common way you burn calories is by your metabolism. According to the Mayo Clinic, “metabolism is the process by which your body converts what you eat and drink into energy. During this complex biochemical process, calories in food and beverages are combined with oxygen to release the energy your body needs to function.” Metabolism can also be classified as your basal metabolic rate, or how many calories your body uses to carry out these functions. The basal metabolic rate makes up about 60 to 80 percent of your total energy expenditure and calorie loss. In addition to your metabolism, a portion of your energy expenditure and therefore loss in calories comes from thermogenesis: the way in which the body produces heat. Thermogenesis makes up 10% of total energy expenditure, leaving only 10-30% for physical activity (which, in reality, is not a lot). 

In terms of that last 10-30%, the body burns the remaining calories by shivering (if cold) or by exercising. Shivering and exercise are viewed as the same inside of the body as they both trigger the activation of what is called brown fat or brown adipose tissue. When you shiver, your muscles involuntarily contract to generate warmth to regulate homeostasis but it also triggers “muscles to secrete a hormone that stimulates energy use in brown fat cells” (according to the National Institute of Health). The same thing happens when you exercise! In another example, brown fat helps infants who don’t know how to shiver yet regulate their body temperature. 

While brown fat burns calories to generate heat, something called white fat stores calories as heat / insulation to keep you warm. As you can assume, It is better to have more brown fat than white fat as large amounts of white fat, and this insulation, can lead to obesity. This is because white fat stores energy in large lipid droplets throughout the body. On the other hand, brown fat contains smaller lipid droplets and higher amounts of mitochondria. This increase in mitochondria causes an increase in ATP or energy production and therefore increase in energy expenditure and calorie loss. 

So how is this related to energy expenditure and calorie burning, you ask? Many people believe that you can burn more calories in the cold because of this brown fat. Although this is true, you need at least 2 hours in 66 degrees fahrenheit (or lower temperature) in order to see the extreme effects of the body activating the brown fat and burning more calories. On the other hand, many believe that you will burn more calories in the heat (or hot conditions) because sweating more must mean your body is working harder and losing more calories, right? This is not always the case – releasing more sweat doesn’t always mean you are releasing more energy and losing more calories. Rather, in the case of very hot conditions, like hot yoga for example, the sweat you are releasing only causes you to lose more water, not calories.   

There are pros and cons to any type of exercise, but ultimately choosing to work out in hot or cold conditions to promote weight loss, may do more harm for you than good, especially if you are new to the exercise scene as your body may not react well to these temperatures. To promote weight loss, you must be in a calorie deficit –  burning more calories than you are in consuming. This is the best and really the only way to lose weight (along with exercise). 

 

Trade Your Treadmill for… a Protein?

As humans, we have recognized that regular exercise has many benefits for everyday life. It helps our physique, our muscle and bone health, and it also is responsible for the release of endorphins that improve our mood. However, exercise is time consuming, and some of us just lack the motivation for regular physical exertion.  Scientists at Michigan Medicine have been researching the protein Sestrin in mice and flies, and they have found that “it can mimic many of exercise’s effects,” potentially creating a way to gain the benefits of exercise without actual exertion.

In their experiment, the Michigan scientists used two groups of flies. One group of flies was deprived os Sestrin, while the other group’s Sestrin levels were enhanced. When put through an extended period of exercise, the flies that lack Sestrin did not have any of the typical muscle development and endurance that comes from working out. The flies that received amplified amounts of Sestrin also didn’t progress. However, the Sestrin-boosted flies didn’t receive the benefits of exercise from exertion, because they had already acquired those benefits  from their increased Sestrin levels. In performing the same experiment with mice, “Mice without Sestrin lacked the improved aerobic capacity, improved respiration and fat burning typically associated with exercise.” According to the nature.com article “Sestrins are evolutionary conserved mediators of exercise benefits,” “in vertebrates, endurance training leads to increased mitochondrial biogenesis/efficiency, decreased triglyceride storage, improved insulin sensitivity, and protection of both muscle and neural functions.” Basically, if Sestrin indeed proves to be the magic exercise replacement, it could help alleviate some of the negative physical consequences of aging.

However, our scientists have 2 main problems in turning Sestrin to a mass produced supplement: it’s a very large molecule, and we are still unsure of how the body naturally produces sestrin during exercise. Therefore, we are not yet at a point where our exercise replacement is a reality, but the probability of future promising results is high.

Personally, I will have to see this protein work on humans before I take seriously the idea of an exercise replacement. A successful Sestrin supplement may be able to mimic the physical benefits exercise, but obtaining physical results through minimal work could be detrimental to the public’s general mentality. Receiving physical benefits through hard exercise teaches cause and effect, mental toughness,  the value of goals, and the satisfaction of well deserved rewards. If this supplement ends up being the fantasized work out supplement everyone is looking for, how will that result-without-the-work mentality impact how we treat other aspects of society? That’s why I don’t see this discovery as a total positive, but I’m excited to see what future studies bring in the development of this long fantasized product.

If you have anything other information or opinions on this topic, feel free to drop a comment below!

 

Exercise causes changes in our gut microbes, but how is unclear

Sarah Campbell was just beginning her assistant professorship in exercise and science at Rutgers University when she became curious about whether exercise could influence microbes in the gut. As an athlete and also having studied cholesterol metabolism and exercise and diet during her PhD and postdoc, she decided that she wanted to pursue the study of exercise and its affect on gut microbes.

Sarah Campell combined forces with microbiologists and toxicologists from Rutgers and a pathologist from Oklahoma City to create an experiment to analyze fecal samples of male mice who are fed a normal or high-fat diet for 12 weeks. Some of the mice in each group were allowed to exercise while others weren’t. The results revealed that physical activity created a unique microbiome in the guts of mice, independent of the diets of the mice. The mice that exercised hosted Faecalibacterium, Clostridium, and Aloobaculum, unlike the sedentary mice. The high-fat diet also led to inflammation in the guts of the mice who didn’t exercise, and this was not seen in the mice that ate a fatty diet and exercised.

The following picture is of gut microbiota (microorganisms that live in the digestive tracts of humans)

The results of this experiment reinforced findings that came out a few years before that showed how exercise prevented weight gain and altered the gut microbes in mice that became obese while eating a high-fat diet. The results of the experiment also aligned nicely with a study that found that lean, sedentary people who exercised for six weeks developed increased levels of Clostridiales, Lachnospira, Roseburia, and Faecalobacterium in their guts. In addition, the study showed how these microbes returned back to baseline levels once the individuals stopped exercising. Obese individuals who began exercising also had changes to their gut microbes; however, these changes were different than those seen in the lean individuals.

Even though the reasons for the difference in changes between the obese and lean individuals aren’t fully understood, the results clearly show how exercise can change the gut microbiota of humans, regardless of diet or body composition.

Can Too Much Sitting Affect The Shape Of Your Heart?

A new research article shows that the heart, besides humans’ joints and tendons, is also optimized for endurance. But, this depends on how active the person is. To conduct this study, scientist gathered 160 adult males from four different groups: football linemen, long-distance runners, inactive adults, and Native American farmers celebrated for their running ability, known as the Tarahumara. Scientist also looked at the hearts of 43 adult male chimpanzees for comparison. 

To examine the heart of these groups, scientist used an ultrasound. When examining the hearts of the four groups, researchers reported in the Proceedings of the National Academy of Sciences that there were noticeable differences in the left ventricle-the thickest of the heart’s four chambers-where blood is pumped. The long-distance runners and Tarahumara farmers had long ventricles with thin walls. This helps to pump large volumes of blood for a long period of time. The inactive adults and the football linemen, who are trained for short, high-intensity exercise, had wider ventricles with thick walls. The same shape was found in the chimpanzees who participate in short, high-intensity exercises like climbing and fighting. They had the shortest and thickest ventricles. 

The wider ventricles and thick walls are beneficial to the chimps and football linemen because during high-intensity workouts when blood pressure in the arteries surge for a short amount of time, it ensures that enough blood is flowing to the brain to keep consciousness. 

The long-distance runners and the Tarahumara farmers are less likely to experience problems like high blood pressure and cardiovascular diseases because of their heart shape.

Fortunately, People’s heart shape is not permanent! Scientists suggest that changes in the heart shape is possible with endurance activities like swimming and running over the course of many years. 

So stop procrastinating and go for that run!

My Gut is Telling Me To Exercise

Researchers at the University of Colorado Boulder have recently discovered that early life exercise can improve the activity of the gut microbiome. The gut microbiome is the next big thing in scientific research as scientists discover its affect on both general health and disease progression.

“Our gut microbiota contains tens of trillions of microorganisms, including at least 1000 different species of known bacteria with more than 3 million genes”. Microbiota, found in the intestine, help with a range of bodily functions such as digesting foods that the stomach is unable to, producing vitamins, and helping the immune system.

https://en.wikipedia.org/wiki/Escherichia_coli#/media/File:EscherichiaColi_NIAID.jpg

https://en.wikipedia.org/wiki/Escherichia_coli#/media/File:EscherichiaColi_NIAID.jpg

‘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,”. Bacteria reside in infants’ intestinal tracts after birth to assist digestion and immune development. Exercise increases the effectiveness of these bacteria, and a  healthy gut biome promotes better brain function and causes antidepressant effects.

Scientists studied exercise and its effects on the gut microbiome using juvenile rats and proved this theory. The rats that exercised during their early lives developed a better microbial structure. The adult rats that exercised could not catch up to the rats that exercised as juveniles.

Do you think that this is an obvious or an unexpected idea, that early life exercise strengthens the gut microbiome? Does metabolic health usually coincide with mental health? Why would the gut microbiome be related to gene-making?

Other Sources

http://www.ncbi.nlm.nih.gov/pubmed/26647967

http://www.medicalnewstoday.com/articles/290747.php 

http://www.scientificamerican.com/article/the-guts-microbiome-changes-diet/

 

 

Epigenetics – Exercise Runs In The Family

It is common fact that people who exercise frequently are more likely to live a longer healthier life, but now new studies show that if a person exercises it can also result in a better life for his or her children and even grandchildren. Before the study of epigenetics people always thought the genome they are born with it the genome they are stuck with. However new science has shown exercise not only changes the outward appearance of our muscles and overall physical health, but also changes our DNA.

Exercise, astonishingly, can effect gene shape, function, and turn them on and off. Scientists now know that genes can actually be quieted or amplified through exercise because biochemical signals are sent out every time a person exercises. This is where epigenetics comes in. Epigenetics doesn’t simply change the gene all together, but instead works its magic on the outside of each gene through a process called methylation. A cluster of atoms surround the genes either denying or amplifying biochemical signals. Scientists believe that even one day of exercise can change methylation patterns.

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One study done by scientists at the Karolinska Institute in Stockholm put the theory of exercise and epigenetic’s to the test. They studied 23 young and healthy men and women. They asked all the participants to work out half of their lower body for three months. This way each member of the study was his or her own control and experimental group. Obviously, after the three months each members leg that was worked out was stronger than the other, but what was much more intriguing was the results at the molecular level. The scientists found significant methylation changes in the cells of the leg that were worked out, averaging 5,000 sights on the genome where there was a new methylation pattern. Many of these methylation patterns were changed on enhancers, which are important for amplifying gene expression. The genes that were most affected were those that play a role in energy metabolism, insulin response, and inflammation within muscles. Exercise, along with many other healthy lifestyle tasks, has shown to cause changes in a persons epigenome. Changes that make a person healthier, but perhaps even more significantly, can make his or her children and grandchildren healthier.

 

http://well.blogs.nytimes.com/2014/12/17/how-exercise-changes-our-dna/?_r=0

 

Regular Exercise Can Change Our DNA

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Most people (hopefully) know that exercise and physical activity are beneficial to almost everyones physical and mental health. Exercising improves one’s mood, boosts energy, controls weight, helps the body fight against diseases, reduces stress, and many more life benefits. A new study  by a group of scientists in Sweden discovered how the influence of physical exercise actually has that beneficial effect on the human body.

The scientists focused their work on 23 young, healthy men and women at the Karolinska Institute in Stockholm. The participants were asked to exercise on stationary bikes for 45 minutes, four times per week, for three months. The scientists understood that it would be difficult to study the full changes on each person because they can’t isolate the other aspects of someone’s life like diet or other behaviors. Because of this issue, each person only exercised one leg so they essentially became their own control group.

After the three months had passed, the scientists clearly saw that the exercised leg was stronger. They also studied the DNA of the muscle cells and compared them between each leg. The genome of muscle cells on the exercised leg had new methylation patterns. DNA Methylation is the process of methyl groups attaching to the outside of a gene and making the gene more or less able to respond to biochemical signals. This entire study is also known as epigenetis. Epigenetics is the study of modifications of DNA influenced by the environment. The scientists found that exercise has a huge effect on human epigenetics based on methylation patterns.

The experiment showed that many of the methylation changes were on the enhancer part of the genome. Enhancers “bind to activator proteins which help connect transcription factors to RNA polymerase and the promotor region to turn on transcription of a gene” (from Mrs. Newitt notes packet). The enhancers amplified the expression of proteins by genes that effect energy, insulin, muscle inflammation and muscle pain.

Exercising is good for you and now we know why. It affects how healthy and fit our muscles become. The results of this study will now help lead other scientists into methylation pattern and gene expression research.

 

Main article:

http://well.blogs.nytimes.com/2014/12/17/how-exercise-changes-our-dna/?_r=0

Other articles of interest:

http://www.ncbi.nlm.nih.gov/pubmed/25484259

http://learningenglish.voanews.com/content/study-regular-exercise-can-change-our-dna/2580467.html

http://www.cell.com/cell-metabolism/abstract/S1550-4131(12)00005-8?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS1550413112000058%3Fshowall%3Dtrue

http://www.mayoclinic.org/healthy-living/fitness/in-depth/exercise/art-20048389?pg=1

How to stick with your New Years Resolutions

 

bicycling  In Tracy Cutchlow’s article “How to Trick Yourself into Exercising” she talks about the difficulty of sticking to your new years resolutions.  Year after year peoplecreate resolutionsthat involve things such as consistent exercise, but they struggle to actually act on their resolution.  So Tracy spoke with a psychologist about possible techniques that would enable her to “trick herself into exercising.”  The psychologist’s technique involved a relatively simple three step procedure.  The first step is to create a “ridiculously realistic goal.”  For example, rather than say you are going to exercise everyday, start off with three days a week.  The next step involves accountability.  This could mean writing notes in your phone or putting a calendar up on the fridge to remind you about your resolution and to help you keep track of your progress.  The final, and most important step, is to create a “painful consequence.”  For Tracy this meant that if she ever failed to maintain her three days a week resolution, she would have to give $500 dollars to an organization that she “hates” (Comcast).  The purpose of the painful consequence is to essentially make breaking your resolution so unappealing that it eventually becomes a rule.  In his book How Children Succeed: Grit, Curiosity, and the Hidden Power of Character, author Paul Tough describes thegeneral science behind how creating rules for yourself is an effective method for maintaining discipline. He writes, “When you’re making rules for yourself, you’re enlisting the prefrontal cortex as your partner against the more reflexive parts of your brain. … Rules are a metacognitive substitute for willpower. By making yourself a rule (“I never eat fried dumplings”), you can sidestep the painful internal conflict between your desire for fried foods and your willful determination to resist them.”  So Tracy Cutchlow’s article provides a means through which we can create rules for ourselves and in turn, successfully adhere to our resolutions.

Image URL: http://commons.wikimedia.org/wiki/Category:Exercise_motivation#mediaviewer/File:Cycling_Time_Trial_effort.jpg

Related Reading:

http://www.paultough.com/the-books/how-children-succeed/

http://www.ballyfitness.com/trick-yourself-into-exercising.aspx

http://www.apa.org/helpcenter/resolution.aspx

Is Exercise really that important?

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Yes, exercise can have a ton of benefits not only for your heart, but for your overall health. First of all, cardiovascular disease (CVD-or heart disease) accounted for approximately 30% of worldwide deaths in 2008. Coronary heart disease and stroke are the leading causes of death. Why such terrible statistics? Well, let’s just say some people don’t take care of their bodies as well as they should be.

Obesity rates are sky high in people, mostly in the United States. It can drastically increase the risk of certain diseases like heart disease and diabetes (type II). Sometimes obesity and heart disease is beyond peoples’ control, either being born with a very slow metabolism or diabetes. However in most cases, heart illness can be prevented. The best way to fend off heart disease would be to exercise. In combination with a healthy diet, exercise is essential to a healthy heart. The essential benefactors of exercise are that it lowers ones blood pressure and lowers ones resting heartbeat. Your heart isn’t working so hard to pump at higher pressures, but it is being conditioned as the muscle it is to pump faster at certain points. Since you are exerting energy, you burn calories and lower your cholesterol levels (cholesterol levels in bulk could lead to clogged arteries). Of course there’s still more to exercise. Exercise leads to the release of natural endorphins, which create a sense of euphoria. Some people describe this state as a “natural high”. The release of endorphins could be considered positive reinforcement to exercise since it makes people literally feel good physically and mentally. In turn people would keep coming back to exercise to feel great and be in shape. This is overall highly effective for helping people to burn more calories (which would mean burning fat and stopping obesity from occurring within themselves). If one does not participate in exercise, they are much more likely to feel worse and overall have a higher risk of heart disease. According to the CDC, over 9 million cases of cardiovascular disease were due to lack of exercise. So why not exercise? Protect your health and well being. Even for a little bit every day, exercising is a helpful tool for better health and better morale.

Do you exercise on a regular basis?

 

Helpful link: http://www.webmd.com/fitness-exercise/guide/exercise-healthy-heart

Sit less, Live longer

Many jobs involve sitting all day

Many jobs involve sitting all day

People tend to spend most of their days sitting. Despite maybe an hour or two spent at the gym, people are sedentary for a majority of their day.  Two studies were performed, one showing that sitting less can slow cells from aging. The other found that standing up, even if your not moving, can be beneficial.

Past studies show that sitting for hours makes a person more likely to develop diabetes, have heart disease, and even die prematurely.

Scientists in Sweden wanted to find out why sitting and illness were linked so they created an experiment altering the time people were sitting or exercising and tracked their physiological results. They focused on the people’s telomere changes. They then compared these telomere lengths to the length of obese, sedentary men and women telomeres. These volunteers then were instructed to exercise and sit less. After six months, the researchers found that their telomeres had lengthened; this means that the cells were getting physiologically younger.

In conclusion, the telomeres shortened much more in response to reduction of sedentary time than to exercising. This means that just be sitting less, one can avoid aging, and other illnesses. Another experiment preformed by Dr. Katzmarzyk found that standing, not even moving, dropped mortality rates. This suggests that standing is not inactive or dangerous, but rather beneficial.

I found this article very interesting to me because I am very active in sports, but I also am sitting a lot in school. I want to know whether the amount of sitting I am doing is greater than my exercise, causing me to age more in the long run. I think it is more important that we are active in school, despite the fact that most of us do after school sports.

image source:

http://en.wikipedia.org/wiki/Occupational_stress  

article source:

http://well.blogs.nytimes.com/2014/09/17/sit-less-live-longer/

other sources:

http://www4.utsouthwestern.edu/cellbio/shay-wright/intro/facts/sw_facts.html

http://www.ncbi.nlm.nih.gov/pubmed/24152707

The Problem With Pain Killers

Photo Credit: Flickr user ragesoss

It is no secret to anyone who knows me that I get injured… a lot.  As a sufferer of everything from neck and shoulder to hip pain I found a new study to be quite encouraging.  A study that was published in The Annals of Internal Medicineproves that exercise and chiropractic care are more effective in treating neck pain that pain killers.  Although exercise is more difficult and chiropractic care more time consuming than taking a pill for pain its is clear that both are better for your body, and your pain level.

Dr. Gert Bronfor who is the author of the study works as a research professor at Northwestern Health Sciences University in Minnesota got 272 people to participate in his study.  He took those people and split them into three groups, the first group went to chiropractors about 15 times in the three month span of the study for sessions lasting approximately 20 minutes.  The second group went to two physical therapy meetings and got a list of exercises to do at home (5-10 reps up to eight times a day).  The final group was told to take common painkillers, and if a doctor said it was necessary stronger narcotics and muscle relaxants.  At the end of the three month study 57% of people who visited the chiropractors and 48% of people who did the exercises reported feeling at least a 75% improvement while only 33% of people in the medicated group reported a 75% reduction in pain.

The study doesn’t end there Dr.Bronfor checked back in a year later and found that 53% of subjects who had chiropractic care, and about the same amount who did exercises, reported a 75% improvement in neck pain.  Only 38% of those who had been taking pain medicine reported feeling 75% better a year later, and most of the participants who had begun to use the pain killers had continued to use them and had increased the dosage and the frequency that they took the pain killers.  This alone lead to the participants having to deal with problems, as the side effects of the pain killers can cause a slew of issues all their own.  So now that you’ve read about the study next time you have a neck ache will you call the chiropractor or reach for that bottle of painkillers?

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