How Many Hot Dogs Can You Eat in 10 Minutes?

Junk Food

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The competitive-eating elite will descend on New York City’s Coney Island this Fourth of July to flex their hot dog eating skills at the annual Nathan’s Famous Hot Dog Eating Contest. Last year, the male winner ate 62 hot dogs and the female winner ate 38 hot dogs in 10 minutes. Competitive eaters are surprisingly slight for the enormous amount of food they are able to consume. Where do all those hot dogs go?

The stomach is not a passive sack but an active organ that expands and contracts. An empty stomach holds about 1/4 cup, but when a meal is swallowed, the stomach expands to hold as much as 6 cups without stretching its walls. Besides relaxing to hold the meal, the stomach’s walls squeeze in and out and back and forth to move the food into the intestines, a process called gastric emptying. Researchers at the University of Pennsylvania wondered if speed eaters’ ability to keep down so many hot dogs was because their stomachs emptied faster or if their stomachs were trained to hold much more food than the average person.

The researchers recruited a professional speed eater and compared his gastric physiology to an individual with a big appetite. A gastric emptying test revealed that the professional speed eater’s stomach emptied slower than the regular eater. After 10 minutes, the regular eater consumed seven hot dogs, and his stomach was not stretched out. In contrast, the speed eater ate 36 hot dogs, and his stomach became a “massively distended, food-filled sac occupying most of the upper abdomen,” the researchers wrote. While the regular eater felt sick, the speed eater said he didn’t feel full, leading the researchers to wonder if the competitive-eating training made the stomach so stretchy and limp that the competitors never get the “full” physiological signal.

Although the study examined only one professional speed eater, the results support the idea that competitive speed eaters could eat large amounts of food in short periods of time not because their stomachs emptied faster but because their stomachs were able to enlarge dramatically.

The record for most hot dogs eaten is 69. How does the stomach look after that many? Not great, this video from ESPN shows.

Maggie KuoMaggie Kuo, PhD, is the former Communications and Social Media Coordinator for APS. Catch more of her writing in the Careers Section of Science Magazine.

 

Looking for a New Physical Challenge? Try a Mountain Ultra-Marathon

Idyllic Alps Valley

The Aosta Valley in Italy where the Tor des Geants is held. Credit: iStock

Of all the extreme endurance races out there—such as the Ironman triathlon or 50- or 100-mile marathons—the Tor des Géants ultra-mountain marathon may be the most extreme. The course is 205 miles long on the rugged terrain of the Italian Alps with a cumulative elevation gain of 24,000 feet. Participants have 150 hours, little more than six days, to complete the course. These feats of ultra-endurance are fascinating for scientists because they showcase how the heart adapts when pushed to the limit. Previous studies have found that after 3- to 15-hour races like marathons and the Ironman triathlon, the heart doesn’t pump as well, a condition referred to as exercise-induced cardiac fatigue. A group of French researchers looked at what happened to the heart after running for over 100 hours in the Tor des Géants. They were surprised to find that unlike with marathons and triathlons, heart function improved after the ultra-mountain marathon race.

During a heartbeat, the heart fills with blood and then squeezes together to push out the blood. In situations in which the body constantly needs more oxygen, such as with exercise, the amount of blood filling the heart is one signal that tells the heart to keep beating harder. The more the heart fills, the stronger the heart contracts.

This study found that the runners’ hearts filled more during each heartbeat. The researchers think it’s because the amount of plasma, which is the liquid portion of blood, increased, raising the overall amount of blood in the body. But why it increased is not clear. Fluid intake could be one factor, says Michael Joyner, MD, an exercise physiologist not involved in the study, in a podcast. Runners in ultra-long races pay extra attention to staying hydrated and often maintain or gain weight from the extra fluids, he says. Stéphane Nottin, PhD, the lead investigator of the study, wonders if inflammation from the extreme physical stress or greater retention of sodium (the kidneys use sodium to absorb water) is also involved.

“Physiology has a long history of expedition-led investigations—whether it’s high altitude, desert—and this paper follows in that wonderful tradition,” Joyner says. Other current ongoing studies in this spirit include a Mount Everest climb to examine cognitive decline at low oxygen levels and a study on the heart of a swimmer swimming across the Pacific.

 

Maggie KuoMaggie Kuo, PhD, is the former Communications and Social Media Coordinator for APS. Catch more of her writing in the Careers Section of Science Magazine.

 

The Antioxidant-Activity Connection

Strawberries and Blueberries Background

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Antioxidants: It’s one of the biggest health buzzwords today. The fabled powers of these mysterious compounds have been featured on daytime TV, plastered on age-defying beauty products and foods in the grocery store, and sold to us as a major reason to frequent juice bars and smoothie shops. Antioxidants are not just an overblown fad, though. They play an important role in keeping our bodies healthy, and they are critical for some people, such as patients with chronic obstructive pulmonary disease (COPD), who can’t get enough oxygen and are inactive as a result.

Antioxidants neutralize molecules called reactive oxygen species (ROS). ROS compounds are byproducts of our body’s metabolism, and too much of them can damage DNA, change cell structure and even kill cells. We can acquire antioxidants to combat ROS by eating foods such as berries, nuts and sweet potatoes. In addition, the body has its own array of natural antioxidants to destroy ROS. Inactivity and low oxygen in the blood (hypoxia) that occur in COPD alter the body’s levels of ROS and antioxidants and can worsen the disease. Maintaining healthy levels of ROS and antioxidants in patients with COPD is a concern for health care providers.

A new study published in the Journal of Applied Physiology found that a low level of activity may be enough to raise antioxidant levels. In a 10-day study, healthy women were confined to strict bed rest, confined to bed rest while breathing air with 32 percent less oxygen, or breathed the low-oxygen air but could stand, walk and conduct normal daily activity. Blood samples were taken before, during and after the experiment to compare the balance between ROS and antioxidant levels. ROS levels increased in all three groups, but the most noticeable difference was in the active group, which had higher antioxidant levels than those on bed rest. Although low oxygen in the blood increased the ROS levels of the participants in the active group, maintaining a somewhat active lifestyle allowed their bodies to produce more antioxidants to buffer the damaging ROS compounds.

There’s a growing population of patients with lung disease who experience both inactivity and hypoxia, so research that helps identify additional consequences of hypoxia and inactivity is paramount for improving care. This study suggests that if these patients can maintain some degree of their physical routine, they may be protected from some of the damaging effects of ROS. This research also provides evidence health care workers can use to educate and encourage healthy behaviors in their patients to reduce complications caused by too much ROS.

Thomas J. Otskey, Hannah Grace Deery, Sandra Bigirwa, Sarah Small and Erin Feldott are students in the Department of Health and Human Physiology at the University of Iowa studying respiratory physiology with Melissa Bates, PhD.

Your Immune System Makes You Mentally Tough

Nut cracker and walnut

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When we have an extremely stressful experience, such as losing a loved one or being constantly bullied by a classmate, our body can react in different ways. Sometimes we overcome the psychological stress and come out stronger than before. Other times, we fall victim to the stress. These experiences build mental “toughness,” also called psychological resilience, which plays an important role in whether we develop mental health disorders, such as depression or anxiety, due to stress. Psychological resilience may sound like something that happens in our head, but it turns out that the immune system is involved in the process.

A group of scientists from the National Institutes of Health reported that the cells of the immune system can change during stress to protect the body from the harmful effects of psychological stress. They made this discovery by stressing out special mice called Rag2-/- mice that do not have immune cells. When stressed, the Rag2-/- mice became anxious and developed depression-like symptoms. When the researchers injected the Rag2-/- mice with the immune cells of stressed normal mice, the Rag2-/- mice became less anxious. This exciting finding tells us that stressed-out immune cells are important in increasing our mental toughness and helping us overcome stressful experiences.

Scientists do not yet understand exactly how stressed immune cells protect the body from psychological stress, but it is very promising that immune cells can one day be used to treat mental health disease and health problems, such as cardiovascular diseases, that are caused by psychological stress.

Dao Ho, PhD

 

Dao H. Ho, PhD, is a biomedical research physiologist at Tripler Army Medical Center.

 

 

The views expressed in this blog post are those of the author and do not reflect the official policy or position of the U.S. Department of the Army, U.S. Department of Defense or the U.S. government.

Go for a Longer Run…Your Bones Will Thank You

Running Distance Bone

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Turning on the television, I inhale deeply as the Olympic marathoners stride across cities to compete for their shot at a medal. As an exercise physiologist, I find all athletes particularly amazing. These men and women devote themselves to their training, pushing for just one more mile with each run. That extra mile provides a sense of accomplishment, but it also strengthens bones with every step taken.

Bone is not a solid block of calcium: It’s a three-dimensional spider-web-like lattice filled with bone cells and fluid containing calcium, phosphate and other nutrients needed by bones. High-impact activities like running compress bone, moving fluid throughout the lattice and increasing the flow of calcium into the cells in the bone. Certain cells in the bone called osteoblasts use the calcium to form new bone material. More calcium entering the osteoblasts means more bone is formed, and the bone becomes denser and harder to break.

A recent study found that not only did running make bones denser, but bone density increased with the distance ran. Researchers in exercise and sport physiology went to the Rock ‘n’ Roll Madrid Marathon and Half Marathon and measured the bone stiffness—which represents a bone’s mineral composition and density—of the marathoners, half marathoners and 10K runners participating in the race. The researchers found that all the runners had stiffer bones than individuals who were sedentary. What was interesting though was that the farther the participants ran, the denser their bones. Longer-distance runners who regularly ran 28 to 33 miles per week had stiffer bones than shorter-distance runners who ran 17 to 24 miles per week. The study also showed that both the male and female runners had greater bone density, suggesting that running is a universal builder of bones.

Increasing and maintaining bone density is important as we age because our risk for osteoporosis—a condition when bones become weaker—increases. On your next run, go that extra mile. Your bones will thank you.

Jessica Taylor updated 6-1-2016

Jessica C. Taylor, PhD, is an assistant professor of physiology in the College of Osteopathic Medicine at William Carey University in Hattiesburg, Miss.