Showing posts with label physiology. Show all posts
Showing posts with label physiology. Show all posts

Wednesday, January 4, 2017

How Long Can A Person Hold Their Breath?



Smithsonian: Ask Smithsonian: What’s the Longest You Can Hold Your Breath?

A dive into the science shows it is possible to override the system

Whhile some studies say most people can hold their breath for 30 seconds to maybe a few minutes at most, Aleix Segura Vendrell of Spain, the most recent Guinness World Record holder, held his for an astonishing 24 minutes and 3 seconds while floating in a pool in Barcelona.

Don’t feel ashamed if you can’t even approach Segura Vendrell’s pulmonary prowess. The ability to hold your breath is hardwired.

Segura Vendrell achieved the record with the help of what is known as an oxygen-assist. He breathed pure oxygen for a certain period of time before he began his extended float—essentially hyperventilating, filling his lungs to capacity with oxygen.

Lung function—and breath holding—varies widely from individual to individual, says Clayton Cowl, chair of preventive occupational and aerospace medicine at the Mayo Clinic in Rochester, Minnesota.

Read more ....

CSN Editor: 24 minutes and 3 seconds is the world record.

Monday, June 18, 2012

How Food is Eaten



Slow-Mo Video: How Food Is Eaten -- Popular Science

Saveur assistant editor Anna Stockwell is a woman of many talents -- she cooked a whole goose last year -- but when we brought the Phantom v642 super-slow-motion super-camera over to the Saveur office, she was on her lunch break. So we just captured this footage of her and her apple.

Even ordinary phenomena are fascinating to watch when they're filmed at 1,000 frames per second! This one reminds us for some reason of a wildlife documentary.

Read more ....

My Comment: Creepy ..... but cool.

Monday, August 1, 2011

Sitting Is Deadly

Sititng. CREDIT: Dreamstime

Sitting Is Deadly, Mounting Research Reveals -- Live Science

Did you hit the gym today? If so, you probably feel like you deserve a pat on the back. But your efforts may be in vain if you spend the rest of the day sitting down.

A growing body of research suggests sitting down for most of the day can be lethal. It has been linked to an increased risk of heart disease, Type 2 diabetes and death from any cause. And a daily jog may do little to negate the deleterious effects of too much time in a chair.

Read more ....

Monday, January 31, 2011

How Much Can You Sweat

Never Stop Sweating Jetportal is Jeffrey Montes on Flickr

FYI: How Much Can A Human Body Sweat Before It Runs Out? -- Popular Science

It all depends on the size, physical fitness and hydration of the person in question, but it’s possible to sweat buckets before heatstroke sets in and we pass out. After all, there are about three million sweat glands on the human body (the highest concentration is on our palms), and the average person aggressively working out perspires about 0.7 to 1.5 liters per hour. Theoretically, if we were attached to a treadmill and pumped full of liquids, it’s possible to keep sweating forever.

Read more ....

My Comment: The sentence that caught my attention was the following .....

.... During the Ironman Hawaii, competitors perspire some 15 liters (about four gallons) throughout the combined marathon run, 2.4-mile swim and 112-mile bike ride.


That's a lot of sweat.

Friday, September 3, 2010

Doctors Seek Way To Treat Muscle Loss

Participants in a University of Florida study use ankle weights to increase strength and balance. Researchers say muscle deterioration is a major reason some of the elderly lose mobility and cannot live independently. Steve Johnson for The New York Times

From The New York Times:

Bears emerge from months of hibernation with their muscles largely intact. Not so for people, who, if bedridden that long, would lose so much muscle they would have trouble standing.

Why muscles wither with age is captivating a growing number of scientists, drug and food companies, let alone aging baby boomers who, despite having spent years sweating in the gym, are confronting the body’s natural loss of muscle tone over time.

Read more
....

Wednesday, April 21, 2010

Maxed Out: What's The Human Speed Limit?

Not quite as fast as the speed of light (Image: Seiko Press Service / Getty)

From New Scientist:

Last year, Usain Bolt stunned athletics fans when he hacked 0.11 seconds off his previous world record for the 100-metre sprint. But what's the ultimate human speed limit?

Intrigued by this question, Mark Denny at Stanford University, California, decided to work out how fast a human could possibly sprint 100 metres. He examined previous records for various athletics competitions - and greyhound and horse races for good measure - since the 1920s, and found that performances in many events followed a similar pattern, improving steadily until they reached a plateau. Horses in the Kentucky Derby, for example, appeared to approach their speed limit in 1949. Since then any improvements have become minimal and increasingly rare.

Read more ....

Tuesday, April 20, 2010

Routine Lifting May Not Be As Bad For Your Back As Thought, Research Suggests

Tapio Videman is a researcher in the University of Alberta's Faculty of Rehabilitation Medicine. (Credit: Photo courtesy the University of Alberta)

From Science Daily:

ScienceDaily (Apr. 15, 2010) — Tapio Videman says back disorders in the working population are among the most costly illnesses in developed countries around the world. Disc degeneration is the main suspected origin of severe back symptoms and the main target in spine surgery.

Read more ....

Tuesday, March 23, 2010

Loneliness Increases Your Blood Pressure

From The Telegraph:

Loneliness can increase blood pressure if you are over 50, according to a new university study.


Lack of connection with others not only makes us unhappy but it is also bad for the wellbeing of your body, research finds.

The psychologists found that there is a direct relation between loneliness and larger increases in blood pressure four years later—a link that is independent of age and other factors such as smoking and obesity.

Read more
....

Wednesday, March 17, 2010

Overcoming Blindness: Other Senses Compensate in Just 10 Minutes



From ABC News:

New Study on 'Neuroplasticity' Shows How Quickly Brain Adapts When Sight, Hearing Cut Off.

Four bikers headed off down a street in Southern California, safely navigating through traffic and past parked cars, and turned onto a narrow bike path leading up a steep hillside. None of them veered off the dirt path, and all safely avoided boulders along the way, always conscious of their surroundings and any possible obstacles.

Read more ....

Saturday, March 13, 2010

Revealed: The 160 Species Living Inside Our Guts

The human gut: home to numerous species of unknown microbes. Science Photo Library

From The Independent:

Scientists have decoded the DNA of the bacteria that take up residence in the typical human body.

Some scientists dream of sending a probe to Mars, others work on ways of exploring the sea bed with robotic submersibles. Now a team of researchers have boldly gone where no human has gone before – they have decoded all the bacterial genes found in the human gut.

Read more ....

Monday, March 8, 2010

Bacteria Rule Our Bodies, Our Planet

Image: The human gut is a virtual zoo, full of a wide variety of bacteria, a new study found. And scientists say that's a good thing. The first results of an international effort to catalog the millions of non-human genes inside people found about 170 different bacteria species thriving in the average person's digestive tract. (CBS/AP)

From CBS News:

Scientists Say the Human Gut is Full of Bacteria; Yes, That's a Good Thing.

(AP) The human gut is a virtual zoo, full of a wide variety of bacteria, a new study found. And scientists say that's a good thing.

The first results of an international effort to catalog the millions of non-human genes inside people found about 170 different bacteria species thriving in the average person's digestive tract. The study also found that people with inflammatory bowel disease had fewer distinct species inside the gut.

Read more ....

Monday, December 14, 2009

Wednesday, December 9, 2009

‘Testosterone’s Aggressive Impact Is A Myth. It Makes You Friendlier’

From Times Online:

It is popularly known as the selfish hormone, which courses through male veins to promote egotistical and antisocial behaviour. Yet research has suggested that testosterone’s bad reputation is largely undeserved.

Far from always increasing aggression and greed, the male hormone can actually encourage decency and fair play, scientists have discovered.

The common belief that it makes people quarrelsome, however, can cause it to have that effect. When people think they have been given supplements of the hormone they tend to act more aggressively, even though it does nothing biological to promote such behaviour.

Read more ....

Tuesday, December 8, 2009

Humans Have Hidden Sensory System

From Live Science:

The human body may be equipped with a separate sensory system aside from the nerves that gives us the ability to touch and feel, according to a new study.

Most of us have millions of different types of nerve endings just beneath the skin that let us feel our surroundings. However, the once-hidden and recently discovered skin sense, found in two patients, is located throughout the blood vessels and sweat glands, and most of us don't even notice it's there.

Read more ....

Sunday, November 29, 2009

Clue To Mystery Of How Biological Clock Operates on 24-Hour Cycle

From Science Daily:

Science Daily (Nov. 29, 2009) — How does our biological system know that it is supposed to operate on a 24-hour cycle? Scientists at the Hebrew University of Jerusalem have discovered that a tiny molecule holds the clue to the mystery.

Human as well as most living organisms on earth possess circadian a (24-hour) life rhythm. This rhythm is generated from an internal clock that is located in the brain and regulates many bodily functions, including the sleep-wake cycle and eating.

Read more ....

Surprise! Your Skin Can Hear

From Live Science:

We not only hear with our ears, but also through our skin, according to a new study.

The finding, based on experiments in which participants listened to certain syllables while puffs of air hit their skin, suggests our brains take in and integrate information from various senses to build a picture of our surroundings.

Along with other recent work, the research flips the traditional view of how we perceive the world on its head.

Read more ....

Wednesday, November 4, 2009

Metabolic Syndrome Is A Killer

From Future Pundit:

High cholesterol isn't as dangerous as a combination of obesity, high blood pressure, and high blood sugar (insulin resistant diabetes).

The team, led by Assistant Clinical Professor of Public Health at Warwick Medical School Dr Oscar Franco, has discovered that simultaneously having obesity, high blood pressure and high blood sugar are the most dangerous combination of health factors when developing metabolic syndrome.

Read more ....

Saturday, October 31, 2009

A Molecule of Motivation, Dopamine Excels at Its Task

Serge Bloch

From The New York Times:

If you’ve ever had a problem with rodents and woken up to find that mice had chewed their way through the Cheerios, the Famous Amos, three packages of Ramen noodles, and even that carton of baker’s yeast you had bought in a fit of “Ladies of the Canyon” wistfulness, you will appreciate just how freakish is the strain of laboratory mouse that lacks all motivation to eat.

Read more ....

Saturday, October 24, 2009

Bigger Creatures Have Bigger Blood Cells

Largest and smallest species of eyelid geckos appear here in proportion, though somewhat smaller than life size. Credit: Zuzana Starostová & Lukáš Kratochvíl

From Live Science:

When it comes to metabolism, size matters—cell size, that is, according to a recent study.

Small animals have faster metabolisms relative to their body size than do large animals. According to the so-called metabolic theory of ecology, that scaling is responsible for many patterns in nature—from the average lifespan of a single species to the population dynamics of an entire ecosystem. Although scientists generally agree on the theory's fundamentals, they disagree on the reasons for the scaling. One camp thinks metabolic rate is driven by cell size; another thinks it corresponds to the size and geometry of physiological supply networks, such as the circulatory system.

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Wednesday, October 21, 2009

Weather 'Shapes Human Body Clock'

From BBC:

Our internal body clocks are shaped by the weather as well as by the seasons, scientists have discovered.

Researchers used computers to model the workings of internal biological clocks.

They found the mechanism had to be so complicated because it was able to deal with varying amounts of light from hour to hour, as well as changing seasons.

It is hoped the research, led by a team from Edinburgh University, could help tackle sleep problems caused by jet lag and shift working.

Read more ....