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Do harder workouts mean more sweat?

It seems like common sense: if you leave a fitness class looking as though you’ve just ridden a log flume, you’ve probably worked harder than if you’re barely glistening. But that’s not always the case, says Adam Collins, a researcher from the Centre for Nutrition, Exercise and Metabolism at the University of Bath.

Sweating, he says, is part of the thermoregulation process. When your body temperature rises, it signals to your brain to sweat in order to cool you down. As the sweat evaporates, it helps regulate your core temperature.

One reason temperature rises is exercise. “When we exercise, the energy we produce to fuel that activity creates heat as a byproduct,” says Collins. The more intense the workout, the more heat is generated – and usually, the more you sweat. But sweat levels can be misleading.

“There are many other factors that influence how much you sweat,” he adds. These include the temperature of the environment, your clothing and humidity. In humid conditions, sweat evaporates less efficiently, making you feel sweatier than usual, whether or not you’re working hard.

“If you went on an easy run on a hot, humid day, you’d probably sweat a lot,” he says. “But on a cold day, you might run at a much higher intensity and barely sweat at all.”

Sweat also varies from person to person. Your fitness level, age, sex, body size and even whether you’re acclimatised to the climate you’re in all play a role.

So, no, sweat isn’t a reliable measure of how hard you’ve worked out. Better indicators of exertion include how hard you’re breathing, your perceived effort, and your heart rate, which you can track with a chest strap monitor or smart watch. That said, “sweat is a good marker of dehydration”, says Collins. So if you come out of a workout dripping, you’ll need to grab a drink.

The Guardian

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Humans may have 33 senses, not 5

For decades, humans know about the five traditional senses famously described by Aristotle. However, a new research study has challenged the long-held notion, claiming that humans could have 22-33 senses.

According to the study, humans experience multisensory input even during the daily routines, thereby revealing a much more complex and interconnected sensory world.

As per researchers’ observations, senses do not work separately, in fact they blend into a unified perception of the world.

How senses interact

Senses are known to influence one other, like what humans see, feel, hear, and smell changes overall perception. For instance, through smell and texture, humans can imagine or perceive different characteristics of products.

Senses beyond traditional five

According to professor Charles Spence from the Crossmodal Laboratory in Oxford, other senses include proprioception, interoception, vestibular system, and agency & ownership.

Proprioception: It gives the awareness of body position

Interoception: Sensing internal bodily changes, such as hunger or heart rate.

Vestibular system: The sense of balance, managed by the ear canals. It can affect visual perception, such as how airplane cabins appear during takeoff.

Agency & Ownership: The feeling that your body parts belong to you and that you are the one moving them.

The study also states that flavor comes from taste, touch, and smell, not taste alone. Similarly, gustation detects basic tastes, including sweet, salty, umami, bitter and sour. Smell contributes the largest share of flavor perception, especially through odors traveling from mouth to nose during eating.

Sound, such as aircraft noise, can change taste perception, thereby making umami-rich foods like tomato juice taste better on planes.

The News Digital

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Vital Water Sources in Arid Environments

At the edges of the valley rocks and mountain folds in Tabuk, a natural phenomenon known locally as “alqultat” stands out—rock cavities formed by erosion that collect and trap water, creating natural reservoirs during rainy seasons.
Scattered across rocky areas, alqultat vary in size and depth based on the region’s geology, serving as vital water sources in dry and semi-arid environments.
These formations have ecological and historical significance. Throughout history, they’ve provided water for human seasonal movements, migrating birds, and local wildlife, especially during dry periods. Alqultat are a testament to how the rocky environment in Tabuk adapts to the climate, with the rock’s composition reducing evaporation and keeping water longer than open streams.
Today, alqultat remain an important natural resource, reflecting the region’s rich landscape and the need to preserve it for future generations.
— SPA

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The potential dangers of disposable e-cigarettes

Many e-cigarette products have been removed from the U.S. market, but disposable e-cigarettes are still available. Disposable e-cigarettes are not meant to be refilled or recharged, but they can be easily opened using instructions found on the internet. Exposure to the liquid contents of e-cigarettes can result in vomiting, tremors, and even death.

What are e-cigarettes?

Electronic cigarettes (e-cigarettes) are devices that heat and aerosolize mixtures of nicotine, flavorings, and other ingredients. Inhalation of e-cigarette vapor is known as “vaping.” E-cigarettes were initially intended to help people stop smoking traditional cigarettes, but the introduction of flavored e-cigarettes has led to the expanded use of these products by adolescents. Over the last decade, flavored e-cigarettes have become very popular among young people, even though e-cigarette sales are supposed to be limited to those at least 21 years of age. A 2021 study found that e-cigarettes were the most used tobacco product among middle- and high-school students. Since the adolescent brain is still growing and is quite sensitive to the pleasant effects of sweet-tasting items, the use of flavored e-cigarettes might result in increased dependence on these products in adolescents, as well as nicotine addiction.

Aren’t e-cigarettes banned?

In response to the increased use of e-cigarettes by minors, in January 2020, the U.S. Food and Drug Administration (FDA) restricted the sale of most flavored, cartridge-based e-cigarettes. This ban meant that major e-cigarette companies like JUUL were no longer able to sell most of their flavored e-cigarette devices. As of October 2021, the only JUUL products that remain available for purchase are the Menthol and Virginia Tobacco pods. A rule prohibiting the use of menthol as a flavoring in cigarettes is currently under consideration. Those who support the 2020 FDA ban argue that the legislation should reduce the use of e-cigarettes by children and adolescents.

What about disposable e-cigarettes?

While the 2020 FDA ban restricted the sale of most JUUL and other cartridge-based e-cigarettes, it did not prohibit the sale of disposable e-cigarettes. Unlike cartridge-based products, disposable e-cigarettes (sold under the brand names Puff Bar, EonSmoke, Posh, and others) are not meant to be refilled. They are battery-powered and do not require external charging. Many disposable e-cigarettes are brightly colored and feature flavors (including cotton candy, watermelon, and sour gummy) that are appealing to children and adolescents. These products are currently legal and can be purchased online as well as at tobacco retailers and are now increasingly popular among adolescents. There are many videos on TikTok that feature the use of disposable e-cigarettes; some of those videos have had millions of views.

Although disposable e-cigarettes are not meant to be refilled and have finite battery lives, there are multiple websites and social media posts that provide detailed instructions for refilling and recharging them. Because these products can be manipulated, opened, and refilled, the potential for exposure to liquid nicotine remains a concern. Some disposable e-cigarettes contain up to 7% nicotine, which is higher than the amount typically found in JUUL pods. Swallowing the liquid contents of a disposable e-cigarette can be very dangerous, especially for young children. Symptoms of nicotine poisoning can include nausea, vomiting, tremors, and heart palpitations. In severe cases, seizures and death can occur.

For now, flavored disposable e-cigarettes remain legal in the US, and these products will likely continue to be used by adolescents and other vulnerable populations. Until additional laws are passed to restrict the use of these products, the potential for toxic effects from them (as well as nicotine addiction) remains a concern.

Kelly Johnson-Arbor, MD,
Medical Toxicologist