Lisa Cuchara, Quinnipiac University

On hot summer days, few things are more refreshing than a dip in the pool. But have you ever wondered if the pool is as clean as that crystal blue water appears?

As an immunologist and infectious disease specialist, I study how germs spread in public spaces and how to prevent the spread. I even teach a course called “The Infections of Leisure” where we explore the risks tied to recreational activities and discuss precautions, while also taking care not to turn students into germophobes.

Swimming, especially in public pools and water parks, comes with its own unique set of risks — from minor skin irritations to gastrointestinal infections. But swimming also has a plethora of physical, social and mental health benefits. With some knowledge and a little vigilance, you can enjoy the water without worrying about what might be lurking beneath the surface.

The reality of pool germs

Summer news headlines and social media posts often spotlight the “ick-factor” of communal swimming spaces. These concerns do have some merit.

The good news is that chlorine, which is widely used in pools, is effective at killing many pathogens. The not-so-good news is that chlorine does not work instantly – and it doesn’t kill everything.

Every summer, the Centers for Disease Control and Prevention issues alerts about swimming-related outbreaks of illness caused by exposure to germs in public pools and water parks. A 2023 CDC report tracked over 200 pool-associated outbreaks from 2015 to 2019 across the U.S., affecting more than 3,600 people. These outbreaks included skin infections, respiratory issues, ear infections and gastrointestinal distress. Many of the outcomes from such infections are mild, but some can be serious.

Germs and disinfectants

Even in a pool that’s properly treated with chlorine, some pathogens can linger for minutes to days. One of the most common culprits is Cryptosporidium, a microscopic germ that causes watery diarrhea. This single-celled parasite has a tough outer shell that allows it to survive in chlorine-treated water for up to 10 days. It spreads when fecal matter — often from someone with diarrhea — enters the water and is swallowed by another swimmer. Even a tiny amount, invisible to the eye, can infect dozens of people.

Another common germ is Pseudomonas aeruginosa, a bacterium that causes hot tub rash and swimmer’s ear. Viruses like norovirus and adenovirus can also linger in pool water and cause illness.

Swimmers introduce a range of bodily residues to the water, including sweat, urine, oils and skin cells. These substances, especially sweat and urine, interact with chlorine to form chemical byproducts called chloramines that may pose health risks.

These byproducts are responsible for that strong chlorine smell. A clean pool should actually lack a strong chlorine odor, as well as any other smells, of course. It is a common myth that a strong chlorine smell is a good sign of a clean pool. In fact, it may actually be a red flag that means the opposite – that the water is contaminated and should perhaps be avoided.

How to play it safe at a public pool

Most pool-related risks can be reduced with simple precautions by both the pool staff and swimmers. And while most pool-related illnesses won’t kill you, no one wants to spend their vacation or a week of beautiful summer days in the bathroom.

These 10 tips can help you avoid germs at the pool:

• Shower before swimming. Rinsing off for at least one minute removes most dirt and oils on the body that reduce chlorine’s effectiveness.

• Avoid the pool if you’re sick, especially if you have diarrhea or an open wound. Germs can spread quickly in water.

• Try to keep water out of your mouth to minimize the risk of ingesting germs.

• Don’t swim if you have diarrhea to help prevent the spread of germs.

• If diagnosed with cryptosporidiosis, often called “crypto,” wait two weeks after diarrhea stops before returning to the pool.

• Take frequent bathroom breaks. For children and adults alike, regular bathroom breaks help prevent accidents in the pool.

• Check diapers hourly and change them away from the pool to prevent fecal contamination.

• Dry your ears thoroughly after swimming to help prevent swimmer’s ear.

• Don’t swim with an open wound – or at least make sure it’s completely covered with a waterproof bandage to protect both you and others.

• Shower after swimming to remove germs from your skin.

Lisa Cuchara, Professor of Biomedical Sciences, Quinnipiac University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Tracy Gleason, Wellesley College and Stephanie Madsen, McDaniel College

The coach, the specialized equipment, the carefully tailored exercise regimen – they’re all key to athletic performance. But imagination might be an unexpected asset when it comes to playing sports.

The idea that athletic achievement depends on the mind isn’t new. Sport psychologists have known for years that working with an athlete on their mental game – visualizing the skill, kinesthetically feeling the swing – has a positive impact on actual performance. But these mental simulations draw only upon mental imagery – seeing and feeling the physical goals in the mind’s eye. Imagination offers a much wider range of possibilities.

What if your game could be helped by an imaginary friend?

In a recent retrospective study of college students, we discovered that imagination comes in handy in athletics in ways that are surprisingly social. The creation of what we termed imaginary athletes – a person or being that a child imagined in the context of athletics – enabled and motivated athletic play, especially for children between the ages of about 6 and 12. Imaginary athletes also provided companionship during athletic play.

Remembering childhood imaginary athletes

The most basic form of an imaginary athlete might be a wall, fence or even tree that makes a good opponent in a pinch. For a child or adolescent practicing a sport alone, a surface that provides a ball return or a steady target for a throw gives opportunities for practice usually requiring other players.

Is it any wonder, then, if the branches of the tree start to resemble a wide receiver’s arms, or an invisible goalie emerges in front of the fence? Solitary play might be a lot more fun if a make-believe teammate could provide an assist, or an invisible coach could appear and shout instructions during practice.

The college students in our study reported that such support, even if imaginary, made them play a little longer or try a little harder as kids.

About 41% of our sample of 225 college students reported creating at least one imaginary athlete at some point in middle childhood or early adolescence. Most, but not all, of these beings fell into three categories based on their characteristics.

The first we called placeholders, such as ghost runners. They are typically generic, amorphous, imaginary teammates created by groups of children when not enough real players are available.

The second type functioned as what we named athletic tools. They helped kids focus on their performance and improve their skills, usually by providing a worthy competitor, sometimes based on an admired professional athlete. The skills of athletic tools were often just above those of the child, drawing out the desire to be better, stronger, faster.

Social relationships, our name for the third kind of imaginary athlete, primarily served emotional functions, relieving loneliness and providing the child or adolescent with a sense of belonging, safety or companionship as they engaged in their sport.

Students who remembered imaginary athletes differed from their peers in two ways. First, more men than women reported creating these imaginary beings, possibly owing to the greater investment in and importance of athletics among boys versus girls. Second, people with imaginary athletes scored higher than those without on a current-day measure of predilection for imagination, but they were not more likely to report having created a make-believe friend or animal as a child.

Imagination is a valuable power

Creating an imaginary other might seem like a quirky, perhaps even childish, addition to sports practice. But actually, this behavior is entirely logical. After all, imagination is the core of human thought. Without it, we couldn’t conceptualize anything outside of the present moment that wasn’t already stored in memory. No thinking about the future, no consideration of multiple outcomes to a decision, no counterfactuals, daydreams, fantasies or plans.

Why wouldn’t people apply such a fundamental tool of day-to-day thought in athletic contexts? Participation in sports is common, especially among school-age kids, and many college students in our study described drawing upon their imaginations frequently when playing sports, especially when doing so in their free time.

The creation of imaginary athletes is also unsurprising because it’s one of myriad ways that imagination enhances people’s social worlds throughout their lives. Above all else, social relationships are what matter most to people, and using imagination in thinking about them is common. For instance, people imagine conversations with others, particularly those close to them, sometimes practicing the delivery of bad news or envisioning the response to a proposal of marriage.

In early childhood, kids create imaginary companions who help them learn about friendship and other’s perspectives. And in adolescence, when people focus on developing their autonomy and their own identities, they create parasocial relationships that let them identify with favorite celebrities, characters and media figures. Even in older age, some widows and widowers imagine continued relationships with their deceased spouses. These “continuing bonds” are efforts to cope with loss through imaginary narratives that are fed by and extrapolate upon years of interactions.

At each point in their developmental trajectory, people might recruit imagination to help them understand, manage, regulate and enjoy the social aspects of life. Imaginary athletes are merely one manifestation of this habit.

Because so many children and adolescents spend a lot of time engaged in sports, athletics can be a major environment for working on the developmental tasks of growing up. As children learn about functioning as part of a group, forming, maintaining and losing friendships, and mastering a range of skills and abilities, imaginary athletes provide teammates, coaches and competitors tailored to the needs of the moment.

Of course, an imaginary athlete is but one tool that children and adolescents might use to address developmental tasks such as mastering skills or negotiating peer relationships. Children who aren’t fantasy-prone might create complex training regimens to practice their skills, and they might manage their friendships by talking through problems with others.

But some report that turning inward generated real athletic and social benefits. “I got confidence out of my [imaginary athletes],” reported one participant. “If I could imagine beating someone, and [winning], then I felt like I could do anything.”

Tracy Gleason, Professor of Psychology, Wellesley College and Stephanie Madsen, Professor of Psychology, McDaniel College

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Kevin Morris, University of Denver and Jaci Gandenberger, University of Denver

In a 2022 survey of 3,000 U.S. adults, more than one-third of respondents reported that on most days, they feel “completely overwhelmed” by stress. At the same time, a growing body of research is documenting the negative health consequences of higher stress levels, which include increased rates of cancer, heart disease, autoimmune conditions and even dementia.

Assuming people’s daily lives are unlikely to get less stressful anytime soon, simple and effective ways to mitigate these effects are needed.

This is where dogs can help.

As researchers at the University of Denver’s Institute for Human-Animal Connection, we study the effects animal companions have on their humans.

Dozens of studies over the last 40 years have confirmed that pet dogs help humans feel more relaxed. This would explain the growing phenomenon of people relying on emotional support dogs to assist them in navigating everyday life. Dog owners have also been shown to have a 24% lower risk of death and a four times greater chance of surviving for at least a year after a heart attack.

Now, a new study that we conducted with a team of colleagues suggests that dogs might have a deeper and more biologically complex effect on humans than scientists previously believed. And this complexity may have profound implications for human health.

How stress works

The human response to stress is a finely tuned and coordinated set of various physiological pathways. Previous studies of the effects of dogs on human stress focused on just one pathway at a time. For our study, we zoomed out a bit and measured multiple biological indicators of the body’s state, or biomarkers, from both of the body’s major stress pathways. This allowed us to get a more complete picture of how a dog’s presence affects stress in the human body.

The stress pathways we measured are the hypothalamic-pituitary-adrenal, or HPA, axis and the sympathoadrenal medullary, or SAM, axis.

When a person experiences a stressful event, the SAM axis acts quickly, triggering a “fight or flight” response that includes a surge of adrenaline, leading to a burst of energy that helps us meet threats. This response can be measured through an enzyme called alpha-amylase.

At the same time, but a little more slowly, the HPA axis activates the adrenal glands to produce the hormone cortisol. This can help a person meet threats that might last for hours or even days. If everything goes well, when the danger ends, both axes settle down, and the body goes back to its calm state.

While stress can be an uncomfortable feeling, it has been important to human survival. Our hunter-gatherer ancestors had to respond effectively to acute stress events like an animal attack. In such instances, over-responding could be as ineffective as under-responding. Staying in an optimal stress response zone maximized humans’ chances of survival.

More to the story

After cortisol is released by the adrenal glands, it eventually makes its way into your saliva, making it an easily accessible biomarker to track responses. Because of this, most research on dogs and stress has focused on salivary cortisol alone.

For example, several studies have found that people exposed to a stressful situation have a lower cortisol response if they’re with a dog than if they’re alone – even lower than if they’re with a friend.

While these studies have shown that having a dog nearby can lower cortisol levels during a stressful event, suggesting the person is calmer, we suspected that was just part of the story.

What our study measured

For our study, we recruited about 40 dog owners to participate in a 15-minute gold standard laboratory stress test. This involves public speaking and oral math in front of a panel of expressionless people posing as behavioral specialists.

The participants were randomly assigned to bring their dogs to the lab with them or to leave their dogs at home. We measured cortisol in blood samples taken before, immediately after and about 45 minutes following the test as a biomarker of HPA axis activity. And unlike previous studies, we also measured the enzyme alpha-amylase in the same blood samples as a biomarker of the SAM axis.

As expected based on previous studies, the people who had their dog with them showed lower cortisol spikes. But we also found that people with their dog experienced a clear spike of alpha-amylase, while those without their dog showed almost no response.

No response may sound like a good thing, but in fact, a flat alpha-amylase response can be a sign of a dysregulated response to stress, often seen in people experiencing high stress responses, chronic stress or even PTSD. This lack of response is caused by chronic or overwhelming stress that can change how our nervous system responds to stressors.

In contrast, the participants with their dogs had a more balanced response: Their cortisol didn’t spike too high, but their alpha-amylase still activated. This shows that they were alert and engaged throughout the test, then able to return to normal within 45 minutes. That’s the sweet spot for handling stress effectively. Our research suggests that our canine companions keep us in a healthy zone of stress response.

Dogs and human health

This more nuanced understanding of the biological effects of dogs on the human stress response opens up exciting possibilities. Based on the results of our study, our team has begun a new study using thousands of biomarkers to delve deeper into the biology of how psychiatric service dogs reduce PTSD in military veterans.

But one thing is already clear: Dogs aren’t just good company. They might just be one of the most accessible and effective tools for staying healthy in a stressful world.

Kevin Morris, Research Professor of Social Work, University of Denver and Jaci Gandenberger, Research Associate of Social Work, University of Denver

This article is republished from The Conversation under a Creative Commons license. Read the original article.