A jousting knight wears his heart on his sleeve. Credit: iStock
In medieval times, a jousting knight would wear the colors of the lady he was courting tied around his arm. Hence, the phrase “Wear your heart on your sleeve” was born. Today, we use this romantic phrase to describe someone who expresses their emotions openly. How applicable that ancient phrase really is to maintaining a healthy heart!
In a landmark paper, a group of scientists discussed how stress and social interactions with others affected the health of the heart. It is well-known that stress is a major factor in the development of heart disease. This is because stress is a double whammy: It activates the “fight-or-flight” nervous response, and it causes inflammation in the cells that line blood vessels. Both of these events can damage blood vessels in the heart.
Research shows that positive social interaction expressing emotion is important for heart health. Support from a spouse or partner, friends or other groups can reduce stress and help you stick to a healthy diet and exercise program to minimize your risks.
Heart disease is the leading cause of death worldwide, with annual deaths creeping up to 24 million. Reducing stress and anxiety is an important aspect of keeping your heart healthy. Exercise, yoga, meditation and even deep breathing can promote a sense of calm when tensions mount. Try running or yoga with a friend or join an exercise class to keep you on track for a healthy heart. Go ahead, wear your heart on your sleeve—it’s good for you!
February is American Heart Month. You can find more information about keeping your ticker ticking on the American Heart Association’s website.
Audrey A. Vasauskas, PhD, is an assistant professor of physiology at the Alabama College of Osteopathic Medicine.
The American Heart Association recommends that adults get at least 30 minutes of endurance exercise every day to keep your heart, lungs, and circulatory system healthy. A daily workout can help reduce your risk of developing diseases such as diabetes, heart disease and stroke. Endurance exercise is basically any activity that increases your breathing and heart rate for an extended period of time. Examples include:
- brisk walking
- climbing stairs
During exercise, your blood vessels expand (dilate), increasing blood flow, and delivering more oxygen to your working muscles. Over time, exercise helps your blood vessels become more flexible. This flexibility allows the vessels to dilate more quickly to deliver blood and oxygen to your muscles. Long-term endurance exercise also increases the number of small blood vessels (capillaries) in your body. All of these things help carry more oxygen to your organs and remove waste more quickly. As a result, you can enjoy better athletic performance, such as being able to jog farther, run faster or swim longer distances.
A recent study in the American Journal of Physiology—Heart and Circulatory Physiology showed that endurance activity may help blood vessels grow by increasing the number of microvesicles in your blood. Microvesicles are small particles that are shed into your blood from all types of cells in your body. When volunteers in the study rode a stationary bicycle, they produced more microvesicles than when they were sitting and resting. The number increased even more when they pedaled faster. The researchers then added the volunteers’ microvesicles to endothelial cells—a type of cell that lines the blood vessels and is responsible for expanding and contracting them. They found that microvesicles caused endothelial cells to grow twice as fast. In other words, when you exercise, the number of microvesicles increases, which in turn helps your blood vessels grow.
Now you know why exercise builds a better circulatory system, so get moving!
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.
With winter upon us, it is a good reminder that cold weather is not an excuse for inactivity. Athletes from cold-weather climates, such as the Nordic countries, are not content to stay indoors during winter. In fact, cross-country skiers from these colder climates might be considered the premier human aerobic athletes.
Although some picture cross-country skiing as slowly shuffling along at a leisurely pace, the reality of competition is much different. For example, the winner of the 50 km (31 miles) freestyle at the 2014 Winter Olympics finished the race in less than one hour and 47 minutes. That’s longer than a marathon but finished in less time. And these races typically go uphill for 50 percent of the time!
Physiologically, skiing is interesting from many perspectives. The biomechanics of skiing are interesting because the arm and leg movements must be coordinated to efficiently move forward. The whole-body nature of skiing makes the physiology fascinating to study. Cross-country skiing puts large demands on the heart to deliver blood and oxygen to exercising muscle. This challenge is greater than for running or cycling (which engages only the legs) because both the arms and the legs need to work with skiing.
The amount of blood going to the arms versus the legs constantly changes, too. These changes are based on the hundreds of technique transitions needed to cross the varying terrain during a race. The great physical endurance required improves the ability of cross-country skiers’ muscles to use oxygen. These athletes have some of the highest levels of oxygen consumption (VO2max) on record. Legendary physiologist Bengt Saltin and other researchers have used the unique whole-body nature of cross-country skiing to study blood flow delivery. This approach has provided us great insight into the regulation of blood flow in both athletes and non-athletes.
Cross-country skiers demonstrate that cold weather is not an excuse to be sedentary, but rather an excuse to be great.
Benjamin Miller, PhD, is an associate professor in the department of Health and Exercise Science at Colorado State University. He co-directs the Translational Research in Aging and Chronic Disease (TRACD) Laboratory with Karyn Hamilton, PhD.
It’s been a physiology-full 2016 on the I Spy Physiology blog! From exercise to respiration to heart health and beyond, we’ve explored how the bodies of humans and other animals work, adapt and react. Today, we take a look back at our 10 most read posts of the year.
Concussions among football players was headline news in 2016. Against this backdrop, our most popular post of the year looked at how woodpeckers can bang their heads roughly 12,000 times a day at a greater force than the average football hit without sustaining a head injury. Posts about the amazing endurance of Iditarod sled dogs and a researcher’s excellent explanation of what physiology is and why it’s important round out the top three. Check out this year’s top 10:
If you’ve got a topic that you’d like us to cover in 2017, we’d love to hear from you! Share your thoughts in the comments or send us an email.
Winter officially begins next week with the winter solstice—the day of the year with the fewest hours of sunlight—on Dec. 21. With the cold weather and shorter days, you might be tempted to curl up under a blanket until the spring thaw. Whether you plan to hibernate or get outside to enjoy the chill, we’ve got some good reads about how our physiology responds to the cold weather.
Check out these throwback posts featuring cold weather tips to help you stay safe and healthy during the coldest months:
Have fun, be safe and take note of how your body adapts to the season!
– Stacy Brooks and Erica Roth
Alcohol and heart health have a complicated relationship. Recent research suggests that moderate drinking may reduce your risk of stroke. But for some people, even one or two drinks a day may increase the risk of a form of heart disease called atrial fibrillation (AFib).
AFib is an irregular heartbeat of the two upper chambers of the heart (atria). During an episode of AFib, the atria beat quickly and out of synch with the lower chambers of the heart (ventricles). This irregular pattern can cause blood to clot in the heart, which also increases the risk of stroke.
A recent study published in the Journal of the American Heart Association suggests that over time, moderate alcohol consumption may cause the left atrium to become larger. The enlargement of the heart chamber can lead to AFib in some cases. This is one of the first studies to show in a large population of humans that structural changes in the heart can cause AFib. Previously, AFib had been thought to arise as a result of problems with the electrical impulses in the heart.
For most people who follow a heart-healthy diet, exercise and don’t have high cholesterol or high blood pressure, the occasional drink probably won’t hurt or lead to AFib. However, it’s a good idea to be aware of the alcohol-related heart disease risk as office parties and family gatherings get into full swing this holiday season.
Learn more about atrial fibrillation from the Mayo Clinic.
— Erica Roth
Lung cancer is the leading cause of cancer-related death for both men and women in the U.S., according to the American Cancer Society (ACS). Responsible for 1 in 4 cancer deaths, there were approximately 224,390 new cases and 158,000 lung cancer deaths in 2016 alone.
Despite the seemingly grim outlook for lung cancer patients, many people diagnosed with the disease are cured. The key for these positive outcomes is early cancer detection and treatment. A number of new and innovative therapies have been developed that have contributed greatly to the prolonged survival of patients. However, as the statistics show, there is still a vital need for better treatment options to further improve survival rates.
A main focus in cancer research has been to target the cell communication that causes normal cells to change into cancerous cells. Our understanding of these processes has grown significantly during the past decade, and scientists have been able to point to a number of proteins that are involved in this transformation. Recently, a group of scientists combined its knowledge of these cellular processes with a high-tech anti-cancer drug delivery method to wipe out lung cancer cells. They used nanoparticles with a drug that specifically targeted a protein known to be involved in this cell-changing process. Nanoparticles are very tiny particles between 1 and 100 nanometers—about 1,000 times smaller than a cell—that are made of special material depending on their use. Here, they used a special type of nanoparticle that allowed the drug to get into the lung cancer cells.
In addition to new therapies to fight cancer, there are low-tech ways you can reduce your cancer risk. One of the main causes of lung cancer is smoking tobacco products. The No. 1 way to stay healthy is to avoid tobacco, including smokeless tobacco products, which can also cause cancer. Tomorrow, November 17, is the Great American Smokeout—a good day to make a commitment to quit. ACS has a number of stop-smoking resources available on its website. Additionally, eating healthy and staying active will reduce your risk for cancer-related illness.
Audrey A. Vasauskas, PhD, is an assistant professor of physiology at the Alabama College of Osteopathic Medicine.
With Halloween next week, you may be planning to head to a haunted house or cozy up on the couch with popcorn and a horror flick. Either way, you’re probably hoping for a good scare.
Enjoying the thrill of a scary movie or riding a rollercoaster isn’t the same as a real life-threatening situation, but your body doesn’t always know the difference. This is because the same senses are triggered when you’re startled in a safe environment as when there’s a genuinely fearful situation. Whether the fear is real or fake, your body leaps into action to prepare for whatever is going to unfold:
- Your cardiovascular system pumps more blood and your heart beats faster.
- Your brain sends adrenaline to your skeletal muscles, getting ready to move.
- Your pupils dilate so you can see better.
- Your digestive system slows down until the threat has passed.
Referred to as the “fight or flight” response, the human body functions similarly to how it would have thousands of years ago when faced literally with these two options: fight (for food or for your life, for example) or flight (run away).
During the physiological reaction to fear, scientists believe the brain stimulates the production of dopamine, a chemical that activates the pleasure center of the brain. Many people enjoy the feeling of a good scare and pursue other thrill-seeking behaviors to get the same “high.” Research suggests that thrill-seekers may have different brain chemistry than those who don’t enjoy a heart-pounding experience. If you don’t like to be scared, skip the tricks, enjoy the treats and remember to breathe deeply during this spooky season.
No matter where you fall on the scare scale, be safe this Halloween!
– Erica Roth
Want to learn more about physiology without going back to school for a PhD? Check out www.physiologyinfo.org. The website, hosted by the American Physiological Society, goes in-depth to explain the multi-faceted field of physiology to nonscientists. In addition to examining hot and emerging areas of research such as brain physiology, obesity and exercise, we look at the how the body’s systems work individually and together to keep us going every day.
Our reference library houses quizzes that will test your physiology smarts, dozens of podcasts on cool research findings, a library of vintage equipment dating as far back as the 1870s and much more. We also feature timelines that highlight important milestones and people in the history of physiology.
We hope the site will serve as a helpful and informative resource about our area of research. Check back often for new information. And if you have questions you’d like us to address, let us know!
– Stacy Brooks
Take our physiology quizzes!
If you’ve been following along with the I Spy Physiology blog, you may be feeling like a physiology wiz. APS member-physiologists have developed a series of quizzes to help you test your physiology smarts and, perhaps, teach you something new. Visit www.physiologyinfo.org to take one of our systems quizzes (cardiovascular, digestive, endocrine or respiratory) or check out our general physiology quizzes (part 1 and part 2) that test your knowledge of physiological functions throughout the body. Share the quizzes with your friends and colleagues to compare scores, and remember to check back often for new quizzes as they’re posted.