Discovering the Five Sleep-Wake Profiles: Why Staying Up Late and Waking Early Isn’t Enough for Optimal Health

A groundbreaking study conducted by researchers at McGill University indicates that human sleep patterns, or chronotypes, exist on a broader biological spectrum. Each subtype is linked to distinct health and behavioral traits, challenging the conventional ‘early riser vs. night owl’ classification.

Zhou et al. The study identifies five distinct biological subtypes, each related to various behavioral patterns and health conditions. Image credit: Wok & Apix.

Chronotype refers to the specific time during the 24-hour cycle when an individual naturally feels the most alert or is prepared for sleep.

Previous research has often associated late-onset chronotypes with health issues, yet the findings have frequently been inconsistent.

“Instead of asking if night owls face greater risks, it may be more insightful to explore which specific night owls are at risk and why,” explains Dr. Yue Zhou, a researcher at McGill University.

Utilizing AI technology, Zhou and colleagues analyzed brain scans, questionnaires, and medical records from over 27,000 adults in the UK Biobank.

Their findings uncovered three night owl subtypes and two early riser groups.

One early riser subtype exhibited the fewest health issues, while the other was more closely linked to depression.

Night owls performed better on cognitive assessments but faced difficulties in emotional regulation.

One night owl group was prone to risk-taking behaviors and cardiovascular challenges, while another group showed higher tendencies for depression, smoking, and heart disease.

“These subtypes are not merely characterized by their sleep times,” stated Dr. Danilo Buzdok from McGill University.

“They represent a complex interaction of genetic, environmental, and lifestyle factors.”

Instead of categorizing sleep types as good or bad, the researchers emphasize how risks and strengths are distributed differently among the five profiles.

A nuanced comprehension of sleep profiles can clarify why identical sleep schedules impact individuals differently, promoting research and sleep support that transcends a one-size-fits-all methodology.

“In today’s digital age and post-pandemic world, sleep patterns are more diverse than ever,” remarks Zhou.

“Recognizing this biological diversity may ultimately lead to more personalized strategies for sleep, work schedules, and mental health support.”

For further details, refer to the published findings in the Journal on December 22, 2025, Nature Communications.

_____

L. Joe et al. (2025). Potential brain subtypes of chronotypes reveal unique behavioral and health profiles across population cohorts. Nat Commune 16, 11550; doi: 10.1038/s41467-025-66784-8

Source: www.sci.news

Why Natural Ovulation is the Optimal Choice Before IVF Frozen Embryo Transfer

IVF Treatment Options

Exploring Diverse IVF Treatment Options: Insights and Effectiveness Research

Credit: Zephyr/Science Photo Library

Recent findings from a comprehensive randomized trial indicate that natural ovulation methods for preparing the uterus for frozen embryo transfer after in vitro fertilization (IVF) are equally effective and come with fewer risks compared to traditional hormone therapy.

Emerging data suggests that for women with strong responses to IVF treatment (which can yield multiple eggs), freezing embryos and transferring them in a later cycle can enhance success rates. Consequently, frozen embryos now represent the majority of embryo transfers conducted globally.

Post-IVF, the crucial timing for transferring frozen embryos into the uterus occurs during the menstrual cycle when the endometrium (the uterine lining) is adequately thick to facilitate implantation.

Women can opt for either a medicated cycle, which involves administering estrogen and progesterone for uterine preparation, or a natural cycle, where the body’s natural hormone production is monitored, assuming regular cycles.

Determining the optimal choice remains complex due to a lack of substantial trials evaluating the complications linked to these varying methods.

To address this uncertainty, Daimin Wei and a team from Shandong University in Jinan, China, conducted a large-scale clinical trial involving 4,376 women across 24 fertility treatment centers. All participants were aged 20 to 40 and were slated for a single frozen embryo transfer. Participants were divided equally between the medicated and natural cycle groups.

“This is the randomized controlled trial we’ve been waiting for,” remarks William Bucket from McGill University in Montreal, Canada, who was not involved in the study.

Live birth rates were comparable between both methods, with 41.6% in the natural cycle group and 40.6% in the medicated group. This suggests that natural ovulation is as effective as hormone therapy for preparing the uterus for embryo implantation.

However, an analysis of maternal complications during and after pregnancy revealed notable distinctions.

Women utilizing natural cycles exhibited a lower likelihood of preeclampsia, a severe condition marked by elevated blood pressure, along with fewer incidences of early pregnancy loss. They were also less prone to develop placenta accreta spectrum, a condition that makes the placenta difficult to detach following childbirth. Additionally, this group had reduced rates of cesarean sections and severe postnatal hemorrhage.

“These risks impact both maternal and fetal health during pregnancy and hold significance for long-term postpartum health,” states Wei.

“This research is vital,” notes Tim Child, Chair of the Scientific and Clinical Progress Advisory Committee of the UK Human Fertilization and Embryology Authority. The clinic now advises individuals with regular menstrual cycles that both natural and medicated methods yield similar success rates.

However, Child points out that there is evidence suggesting natural cycles may lower the risk of preeclampsia. This reduction may be attributed to the presence of the corpus luteum, which regulates hormones necessary for preparing the uterus for pregnancy.

“This extensive study corroborates and expands on previous findings, especially concerning significantly lower rates of preeclampsia, early miscarriage, placenta accreta, cesarean sections, and postpartum hemorrhage linked to the natural cycle approach,” Child asserts.

Wei’s team is set to analyze blood samples gathered during the trial to identify potential biomarkers that could shed light on the differences observed in pregnancy complications.

Topics:

Source: www.newscientist.com

New Study Uncovers the Optimal Walking Pace for Longevity and Health

Walking slightly faster than usual can markedly enhance the health of seniors, according to new research from the University of Chicago.

Specifically, researchers discovered that frail or at-risk adults can bolster their health and quality of life by increasing their walking speed by at least 14 steps per minute over their normal pace.

“Increased walking speed is a well-documented protector against mortality,” stated Dr. Daniel Rubin, associate professor of anesthesia and critical care at the university, as reported by BBC Science Focus. “Older adults who walk more briskly tend to live longer.”

The study involved 102 participants from 14 retirement communities, implementing a structured walking program over four months.

During this period, 56 participants maintained a normal walking pace while the remaining 46 were encouraged to walk quickly yet safely.

At the conclusion of the program, each participant’s walking speed was assessed during a 6-minute walk.

While all participants reaped benefits from the walking program, those who managed around 100 steps per minute showed the most significant improvement in their frailty levels from the start to the end of the study.

Researchers had long recognized that walking speed correlates with the health of older adults, but previous recommendations on how to enhance pace were often subjective and challenging to quantify.

Traditionally, older adults were advised to walk at a pace where talking was easy but singing was difficult.

Frail adults are at increased risk of falls, hospitalization, and loss of independence. Warning signs include weakness, unintentional weight loss, and fatigue. Image Credit: Getty.

“We can offer the elderly straightforward and targeted advice like, ‘Try to walk five steps per minute faster than your normal pace.’

Healthcare providers and researchers can use wearable technology, such as accelerometers, to track walking speed. Rubin and his team are currently developing an app for individuals to measure their speed at home.

In the meantime, Rubin suggests utilizing a metronome to establish a baseline walking pace, syncing steps with the metronome’s beat.

“Once a comfortable pace is established, you can gradually add 5-10 steps per minute to enhance your cadence,” he noted. “The target is to aim for an increase of 10-15 steps per minute, which is acceptable.”

Nonetheless, Rubin emphasizes that seniors must walk safely and monitor for any symptoms such as chest pain, shortness of breath, or dizziness.

“Our hope is that older adults will find this a practical strategy for guiding walking intensity, enabling them to live longer and continue engaging in activities they enjoy,” he added.

read more:

About our experts

Dr. Daniel Rubin is a physician at the University of Chicago and an assistant professor of anesthesia and critical care. His interest in gait studies stems from his clinical experience with elderly patients preparing for surgery.

Source: www.sciencefocus.com

The Optimal Method for Dropping Eggs

The Egg Drop Challenge is a time-honored tradition for many physics students. Participants often wrap eggs in cotton balls, tape, and various materials before dropping them from a school rooftop. Anyone who’s taken part knows how challenging it can be to design a structure that keeps the eggs intact upon impact. (That wasn’t my finest creation back in middle school!)

After the eggs break, teachers often share insights about the physics involved, suggesting that eggs dropped vertically tend to crack less than those resting flat.

But is that really accurate?

Following her experience with the egg drop challenge, Tal Cohen, an engineering professor at MIT, began to question whether traditional claims about falling eggs held up under scrutiny.

“It relates to the static behavior of the egg,” she remarked. “The dynamics of the impact are quite different.”

To validate her hypothesis, she conducted tests in the lab with eggs. Her findings turned out to be more complex; Thursday’s paper in the journal Communications discusses how eggs resting horizontally are actually less prone to cracking.

To carry out their experiments, the research team procured over 200 eggs from Costco (an advantage when prices were lower in 2023). They employed devices to crush some eggs and measure the force necessary to crack the shell. Remarkably, they found that eggshells broke under similar forces, regardless of whether the eggs were horizontal or vertical.

Next, they actually dropped the eggs. For testing purposes, they dropped them from a modest height of about 8 mm, allowing them to observe varying outcomes. When dropped from a greater height, all the eggs broke, regardless of their orientation.

Significant differences in outcomes were noted. Eggs dropped on their sides were much less likely to crack. Upon landing, their shells could compress, absorbing some of the impact. Conversely, eggs landing on their ends exhibited more rigid shells with no similar flexibility.

Joseph E. Bonavia, a graduate student in engineering at MIT and co-author of the paper, noted this similarity to human physiology.

“When falling from a height, you want to avoid locking your knees, as that can lead to fractures,” he explained. “Instead, you bend your knees—much like the eggs do.”

The way we typically cook eggs may have contributed to the misconception that eggshells are most fragile, according to Brendan M. Uniquewicch, another MIT graduate student and co-author. We often break eggs at their midpoint, which results in a long crack that allows for clean separation. As these experiments illustrate, breaking at that point causes the shell to cave inward—an undesirable outcome for omelet-making.

Indeed, the experiments challenge our intuitions about how objects behave when they fall, Dr. Cohen noted. This highlights the importance for engineering students to remain open to questioning established beliefs.

Has anyone tasted one of these eggs? Due to university policy, researchers can’t consume experimental materials in the lab. However, Dr. Cohen’s dog enjoyed a hearty meal under such restrictions.

Source: www.nytimes.com

The strategies used by 9 sleep researchers to achieve optimal rest

Strategic naps can help you recover from sleep deprivation

Jean Gaumi/Magnum Photo

Sleep researchers devote their careers to understanding how and why we sleep. So what do they do to get a better night’s rest?

It may be comforting to know that even experts don’t always practice what they preach. “I think you’ll find that a lot of sleep researchers are terrible at sleep,” he says. Malcolm von Schantz At Northumbria University, Newcastle upon Tyne, UK.

This article is part of a special series exploring important questions about sleep. Click here for details.

But what many of them agree on is that consistency is key. Here’s what else they had to say:

make a plan

“It’s all about prioritization and planning. For example, I’m a night owl and like to go to bed late and wake up late, so I try not to have meetings before 10am. I’m thinking ahead about the timing of my daily rhythm in terms of what works best for me and how I can adjust my schedule to support that.”

stephen lockleytime shifter

control the lighting

“We keep the lights in our house pretty dim when the sun goes down, turn on as many indoor lights as possible in the morning, and make sure to open the blinds to let some sunlight into the house as soon as the sun goes down. I think it’s really important to minimize night light and maximize morning light.

christopher depnerUniversity of Utah

keep cool

“Sleep science is about how your body [temperature] I need to drop my degree completely…

Source: www.newscientist.com

Optimal AI Implementation Can Enhance Healthcare and Save Lives

Physicians as a whole are a very smart group, but they can be resistant to change. The most famous example is probably the 19th century surgeon who refused to wash his hands when going from the mortuary to the delivery room, spreading undiscovered microorganisms that led to the infant's death. Hungarian doctor Ignaz Semmelweis collected statistics to argue that soap and water can save lives, but was ridiculed and ostracized.

Today, we live in more enlightened times and medical practices are generally supported by evidence, but do we always have the right evidence to make changes? For example, do we always have the right evidence to make changes? There are also indications that bringing it into clinical practice could save lives. As we report in “AI Helps Radiologists Detect Breast Cancer During Physical Exams,” radiologists who choose to use image classification AI to help detect breast cancer are detected one extra case per 1,000 people. Across the health system, the impact can be significant.

Does that mean we should encourage doctors to ditch the scrubs and let the machines do it? Far from it. AI systems with large language models like ChatGPT can pass multiple-choice medical tests, but do poorly at conversational diagnosis (see “AI Chatbot Fails Conversational Diagnosis of Patients”). ). Physicians with a good bedside manner and a listening ear remain essential for now.

We should be bolder when testing medical AI systems in real-world settings

Instead, there are two conclusions that can be drawn from these studies. The first is that we need to be careful in using the general term “artificial intelligence.” Although the two systems we report share underlying neural network technology, image classification is a completely different task than text generation, and the latter risks the AI ​​spitting out plausible but inaccurate results. much higher. In other words, not all AIs are created equal.

The second conclusion is that we need to be more bold in testing medical AI systems in real-world settings, not just in the lab or in simulations. The breast cancer study showed that AI can be a useful tool, giving radiologists control over when to use it. This effort to obtain more evidence could save lives, as it did for Semmelweis, who is now considered a medical hero.

topic:

Source: www.newscientist.com

The optimal times to consume caffeine in the morning: a guide to maximize productivity.

It’s not just called go juice. Caffeine is the most popular performance-enhancing drug in the world. It’s not a nutrient, but a drug, and it’s the most widely consumed psychoactive stimulant by humanity.

In the UK, 98 million cups of coffee are consumed every day. Apart from kickstarting your morning, it has been shown to enhance motor skills like muscle strength and endurance, as well as cognitive skills such as attention, reading speed, and problem-solving abilities.

“There’s a long list of substances believed to enhance performance,” says James Betts, Professor of Metabolic Physiology at the University of Bath. “But I would put caffeine at the top of that list because its effects are so powerful and consistent, affecting almost every tissue in the body.”

Fun fact: Coffee beans are actually seeds from the fruit of the coffee tree – Credit: Sam Brewster

These effects are driven by a diverse biology. Caffeine stimulates the nervous system, increases adrenaline, reduces fatigue, promotes fat burning for energy, and helps conserve glycogen stores, thus improving endurance.

Additionally, it blocks adenosine receptors, a neurotransmitter promoting sleep. This is why coffee makes us feel alert and energized. However, excessive caffeine consumption can lead to irritability, anxiety, and insomnia.

It’s important to time your caffeine intake correctly for optimal effects. Research by Betts suggests that consuming strong coffee after a night of poor sleep can impair blood sugar control over time.

Poor blood sugar control can increase the risk of diseases like type 2 diabetes and heart disease, emphasizing the importance of strategic caffeine consumption.

For improved performance during workouts or activities, Betts recommends consuming coffee 45 to 60 minutes before starting. The effects of caffeine are long-lasting, lasting up to one to two hours in heavy consumers and four to six hours in moderate consumers.

In the 16th century, coffee was banned in Mecca because it was believed to stimulate radical thinking – Photo credit: Getty

While caffeine can enhance cognitive tasks, excessive consumption can lead to poor academic performance due to disrupted sleep quality and daytime sleepiness.

Overall, Betts believes caffeine consumption, especially in the morning, is beneficial for waking up and functioning well throughout the day. It has been linked to preventing various diseases and promoting a healthy, active lifestyle.


About our experts

James Betts is a Professor of Metabolic Physiology at the University of Bath with expertise in nutrition, exercise, and metabolism.


Read more:

Source: www.sciencefocus.com

How health trackers may be hindering your journey to optimal health | Life & Style

ohOne thing after another happened, and I was lying shirtless on the couch, with a wrinkled nose as a cardiologist explained that everything was fine, but that my heart was a little… weird. I can’t remember the exact words, but it was probably just above “quirky,” but not quite weird. He was looking at something else entirely, and had noticed that the valves at the top of my heart were a little weird. It had absolutely nothing to do with why I’d come here, and was unlikely to affect my future health in any way, he said. But now that he’d seen it, he thought it best to tell me. I asked if it was good to know, and he shrugged. “Sometimes?” he said vaguely. “It’s complicated.”

At home, I paid more attention than usual to my heartbeat, listening for any unusual sounds. A few months later, when I experienced what turned out to be indigestion, I went to the doctor, worried that my valve was about to burst. I had no history of anxiety disorders and had never paid much attention to what was going on inside my body, thinking it was inevitably unfathomable, like anything going on in the vast depths of the ocean. But once this flaw was revealed, I became uncomfortably aware of every moving part, of everything that might go wrong.

When I read Caroline Crampton’s recent detailed study of hypochondria, A body made of glass aptly describes health anxiety disorder as “a bodily illness that exists only in the mind,” and my hand immediately went to my chest. From 18th-century quack medicine to today’s health industry, Crampton traces the rise of drugs and devices promising relief from imagined ailments, such as the Zeebo pill (currently £73 on Amazon), which is promoted as a placebo and “you yourself are the active ingredient,” and plans for technology that can observe every part of our minds and bodies. But, she asks, can we ever know too much? Reading recent criticisms of blood glucose monitoring and the rise of the Zoe app, I thought of Crampton’s book. These are part of a growing trend for personalized diets, but along with other criticisms (such as a lack of evidence about their effectiveness), Professor Partha Carr, the NHS’s national diabetes adviser, told the BBC that using a continuous glucose monitor (designed for diabetics) for no health reason can make people obsessed with the numbers and, in some cases, “can lead to eating disorders.”

These are apps for “worried people” – healthy people who worry about their health – a growing market at a time when new technology and the old internet are stoking anxiety by providing vast amounts of knowledge to anyone with Wi-Fi. It’s a successful business model, in that they’re both apps for anxious people and apps that create anxious people. Parents are especially susceptible to marketing, with health anxieties projected onto their children. This month’s New YorkerJia Tolentino detailed her efforts to hide her pregnancy from her phone, which meant not buying baby clothes online, not using a period tracker, and not using pregnancy apps. She wanted to avoid being watched, which can be especially hard when you’re encouraged to watch yourself.

In the time it took me to give birth to my two children, there had been an explosion in the technology offered to parents who wanted to both track their pregnancies (through additional ultrasound scans, for example) and keep an eye on their babies (with devices like stuffed toys with hidden cameras or disks that attach to diapers that alert you when your baby rolls over). By 2020, I was surprised at how hard it was to buy, for example, a baby monitor that didn’t include a camera, didn’t require a Wi-Fi connection, and didn’t capture any data. And yet, despite the desire for parenting technology, Tolentino found that it rarely led to better outcomes for babies, but rather exacerbated or, worse, created the anxieties that led to the purchase of these devices. The control that anxious people seek by monitoring their babies and their bodies is an illusion.

This is disturbing, given the growing number of products targeted directly at them. The global wearable technology market (fitness trackers and other devices) is expected to be valued at $61.3 billion in 2022, and to expand significantly by 2030. My 9-year-old’s school friends regularly compare FitBits. But for some, trackers and the like may be doing more harm than good. New Statesman In 2019, a professor of cardiovascular medicine criticized a large study of atrial fibrillation (a common heart rhythm problem) in Apple Watch owners, saying there was no significant health benefit to testing low-risk people, “the kind of people who wear Apple Watches,” and that the study would “inflict substantial distress” on healthy people who would receive notifications about their irregular heartbeat.

Health anxieties have evolved alongside scientific knowledge, with phrases like “cyberchondria” (anxiety heightened by information found online) emerging and some research suggesting that our new loose connection to medical knowledge is making people more anxious rather than lessening it. I resent the way tech companies prey on these anxieties, creating new concerns for profit. I believe it’s true that we can know too much.

Every now and then, a small pain or memory in my chest will raise a chill and I’ll think about my deformed heart, but in those moments I will tell myself sternly that it’s none of my business what’s going on under the sea, or deep inside my body (as long as it doesn’t affect my life).

Email Eva at e.wiseman@observer.co.uk or follow her on X. Eva Wise man

Source: www.theguardian.com

Ensuring Optimal Brain Function: Tips for Peak Performance

Rawpixel.com/Shutterstock k

Thomas Edison says: He held a steel ball in each hand as he prepared for a nap.. When he nodded, they would fall and wake him up so he could write down ideas that came to him in the moments just before sleep, when he believed he was most creative. But are there really specific times when our brains perform better? And more broadly, are we better at different kinds of thinking at different stages of life? If so, it's worth asking how you can make the most of these mental peaks and maximize your brain's capabilities.?

Edison's methods may have been unorthodox, but It turned out that he was onto somethingas Delphine Audinet It was discovered in 2021 by the Paris Brain Institute and colleagues. They gave 103 slightly sleep-deprived people a seemingly complex math problem that they could solve with simple creative insight. Participants who woke up immediately after falling asleep were almost three times more likely to take a creative leap and solve a problem than those who stayed awake throughout the experiment.

This knowledge may be useful if you are looking for inspiration. But if that's the memory you're trying to optimize, deep sleep is when your brain does the heavy lifting, accumulating new long-term memories from the day's experiences. To get the most out of this, you need plenty of sleep. Adults need 7 to 9 hours of sleep each night. If you are among them, A lot of people…

Source: www.newscientist.com