Lifestyle Medicine Research Hub

Creatine Across a Woman's Life: A Research Map from First Period to Menopause

A comprehensive 2025 review finds women store 70-80% less creatine than men at baseline, meaning supplementation may matter more for women, not less, though large longitudinal studies remain scarce.

Eight Weeks of Creatine in Perimenopause: A Small Trial on Brain and Mood

In a small randomised trial, a medium dose of creatine hydrochloride modestly but significantly improved reaction time and raised frontal brain creatine levels in perimenopausal and menopausal women over eight weeks.

The FDA's Peptide Vote: What Actually Happened in July 2026

An FDA advisory panel narrowly voted to allow six of seven peptides (including BPC-157) to be compounded, directly against the advice of the FDA's own scientific staff, who cited insufficient safety and efficacy evidence for all seven.

BPC-157: What the Actual Human Evidence Shows

A rigorous systematic review screened 544 articles on BPC-157 and found only one human clinical study met its inclusion criteria, meaning the popular peptide's tissue-healing reputation rests almost entirely on animal data.

Why Hormone Therapy Might Make Tirzepatide Work Even Better

In a Mayo Clinic study, postmenopausal women using hormone therapy alongside tirzepatide lost about 35% more weight than women on tirzepatide alone, though the study cannot prove hormone therapy caused the difference.

The Muscle Question: What Large-Scale Data Shows About GLP-1 Drugs and Lean Mass

An analysis of over 670,000 real-world patients found greater lean-body-mass decline with tirzepatide than with semaglutide, using a new method of extracting body-composition data directly from medical records.

Urolithin A and the Immune System: A New Trial in Middle Age

Four weeks of daily urolithin A improved immune cell composition and mitochondrial function while reducing markers of immune exhaustion in a placebo-controlled trial of 50 healthy adults aged 45 to 70.

The First Human Trial of Urolithin A: Is It Safe?

The original first-in-human trial of urolithin A found it safe and well-tolerated at all doses tested, and four weeks of supplementation produced measurable changes in mitochondrial gene activity in elderly participants.

Urolithin A, Spermidine and Fisetin: Comparing the Longevity Compounds

A 2026 review comparing four leading longevity compounds concludes they target genuinely different cellular repair processes, meaning they are likely complementary rather than interchangeable choices.

Six Weeks of Interval Training: A Metabolic Reset After Menopause

Six weeks of cycling interval training improved fat-burning capacity and heart-rhythm complexity in active postmenopausal women, using sessions of just 20 minutes, three times a week.

What Losing Ovarian Hormones Does to the Brain's Energy Supply

In aged mice, losing ovarian hormones reduced proteins linked to brain synaptic connections and mitochondrial energy production, and oestrogen therapy partially, but not completely, restored them.

Why Male and Female Mitochondria Aren't the Same

A 2026 review synthesises evidence that oestrogen, testosterone and progesterone each shape mitochondrial function differently, producing distinct mitochondrial profiles across pregnancy, menopause and other hormonal transitions.

The Stress-Grey Hair Connection Is Real, and It Can Reverse

Tracking individual hairs against personal stress diaries, researchers found that grey hairs can genuinely return to their original colour once a period of intense stress ends, pointing to mitochondria as the likely mechanism.

Mitochondria as Social Creatures: A New Way to Think About Cellular Energy

A influential review argues mitochondria should be understood as social organelles, dividing tasks, forming networks, and communicating with each other in ways that echo social behaviour in animals.

The Energy Resistance Principle: A New Framework for Health and Ageing

A 2025 framework proposes that health depends on a balanced 'energy resistance' in the body's electron flow, where too much or too little resistance, not simply more or less energy, drives ageing and disease.

A Five-Day Fast and What It Does to Your Cellular Powerhouses

Five days of supervised periodic fasting significantly increased mitochondrial DNA and two longevity-linked sirtuin genes in the blood of 51 men and women.

Diet and Exercise Together: A Mitochondrial Reset in Later Life

A 12-month Mediterranean diet and exercise programme reshaped mitochondrial structure and function in older adults with obesity, with the pattern of change differing by each person's underlying metabolic health.

What's Actually in Olive Oil That's Good for Your Mitochondria

A 2025 review identifies three specific compounds in extra virgin olive oil, hydroxytyrosol, oleuropein and oleocanthal, that activate cellular pathways supporting mitochondrial repair and energy production.

The Twin Study That Isolated Sleep's Effect on Mitochondria

In pairs of identical twins who differed in habitual sleep duration, the twin who slept less consistently had lower mitochondrial DNA copy number, a marker of mitochondrial health.

Poor Sleep, Fewer Mitochondria: A Study of 238 Adults

In 238 healthy middle-aged adults, poor sleep quality, and long sleep latency in particular, was independently associated with lower mitochondrial DNA copy number.

When Fatigue, Poor Sleep and Low Mood Combine, Mitochondria Show It

Adults with chronic fatigue who also had both insomnia and depressive symptoms had significantly lower mitochondrial DNA copy number than those with fatigue alone.

Why Melatonin May Be More Than a Sleep Hormone: Its Role in Mitochondrial Repair

A 2024 review details how melatonin, made and used directly inside mitochondria, helps clear damaged mitochondria and restore energy production, beyond its familiar role in sleep.

A Mother's Stress, Measured in Her Mitochondria

Mothers under chronic caregiving stress showed measurably lower mitochondrial health than mothers without that stress, and mitochondrial health tracked with mood in the days just before, not after, blood was drawn.

What We Actually Know About Stress and Mitochondria: A Systematic Review

A systematic review of 23 studies found consistent evidence that psychological stress alters mitochondrial function in animals, but noted that solid human evidence remains scarce, with only six observational studies available.

Mitochondrial Allostatic Load: The Theory Behind Why Stress Ages Cells

An influential 2014 paper proposed that mitochondria are not just victims of stress hormones but active participants, meaning chronically elevated cortisol may directly reshape mitochondrial structure and function over time.

Why Brain Fog Has a Cellular Cause: Perimenopause and Bioenergetic Decline

Perimenopausal and postmenopausal women show measurably reduced brain glucose metabolism and mitochondrial enzyme activity compared with premenopausal women of the same age.

The 30% Drop: How Estrogen Withdrawal Reshapes Cellular Energy

A 2026 review estimates that ATP production efficiency falls by roughly 30% in postmenopausal women, tied to reduced activity in a key mitochondrial enzyme complex.

When Fatigue Has a Measurable Cause: Mitochondria and Ageing

Older adults reporting persistent fatigue showed measurably lower mitochondrial respiration in blood cells than those without fatigue, using precise laboratory oxygen-consumption testing.

Exercise as Cellular Medicine: What Endurance Training Does to Mitochondria

A meta-analysis of randomised trials found that endurance exercise significantly boosts PGC-1α, the master regulator of new mitochondria production, regardless of whether training was continuous or interval-based.

Why the Uncertain Middle Is More Stressful Than Bad News

Tracking stress responses while people awaited a possible electric shock, researchers found that a 50% chance of the shock produced significantly more stress, measured through pupil dilation, skin conductance and self-report, than either a certain shock or certain safety.

What Decades of Research Say About Job Insecurity and Health

Pooling decades of research, this meta-analysis found that job insecurity, the ongoing uncertainty about whether a job will continue, was consistently linked to poorer physical and mental health, lower job satisfaction, and reduced organisational commitment.

Why Some People Find Not-Knowing Worse Than Bad News

Measuring brain activity during a feedback task, researchers found that people high in the personality trait neuroticism showed a stronger neural stress response to ambiguous, uncertain feedback than to clear negative feedback, suggesting some people genuinely find not-knowing more distressing than knowing something is wrong.

The Brain Science Behind Why Not-Knowing Feels So Draining

Synthesising the neuroscience of anxiety, this review proposes that it isn't the threatening event itself but the anticipatory uncertainty beforehand, the not-knowing when, whether, or how bad something will be, that does most of the psychological damage in anxiety.

The Famous Study on How Money Worries Eat Into Thinking

In a shopping-mall experiment and a study of Indian sugarcane farmers tested before and after harvest, researchers found that financial concerns measurably reduced cognitive performance, equivalent to roughly 13 IQ points, in people experiencing scarcity but not in people who were financially comfortable.

The Critique That Complicated 'Poverty Impedes Cognitive Function'

Reanalysing the original scarcity study's data without artificially splitting participants into rich and poor groups, the authors found the pattern held for income treated as a continuous measure across everyone, not just the poor, and flagged that easy, short cognitive tests may have produced misleading ceiling effects.

Why Having Too Little of Anything Can Lead to Borrowing Too Much

Across several lab experiments using time or money as the scarce resource, researchers found that scarcity itself, regardless of the specific resource, led people to focus intensely on the immediate problem while over-borrowing against their future budget, mirroring real-world patterns like poverty-related overborrowing.

The Researchers Who Retested Their Own Famous Scarcity Findings

Running new, higher-powered versions of their own earlier scarcity experiments, the original authors found that the attentional-shift and overborrowing results held up well, but the specific finding that scarcity produces cognitive fatigue on a later task did not reliably replicate.

The Study That Defined What 'Switching Off' Actually Means

Developing and testing a new measurement tool across several working samples, researchers identified four distinct ways people recover from work stress during off hours, psychological detachment, relaxation, mastery experiences, and control, and found each was linked differently to wellbeing outcomes like exhaustion and life satisfaction.

Why Mentally 'Switching Off' Protects You Specifically When Work Is Hardest

Tracking employees over time, researchers found that psychological detachment from work during off hours specifically buffered the negative effects of high job demands on wellbeing and engagement, meaning detachment mattered most precisely when the job was most demanding.

The Largest Study Yet on What Actually Helps You Recover From Work

Pooling 316 samples and over 99,000 participants, researchers found that psychological detachment reliably reduced negative outcomes like exhaustion, but didn't measurably boost positive outcomes like job performance, while relaxation and mastery experiences did both.

Which Kind of Downtime Fights Fatigue Best?

Pooling 54 independent samples, researchers found that psychological detachment after work had the strongest link to reduced fatigue among all four recovery experiences, while having genuine control over one's leisure time had the strongest link to increased vigour and energy.

What Three Decades of Research Say About Faking It At Work

Pooling 95 studies, researchers found that surface acting, faking or suppressing emotions to meet a job's expectations, was substantially linked to poorer wellbeing and worse job attitudes, while deep acting, genuinely trying to feel the required emotion, showed weak links to harm and was instead linked to better customer outcomes.

Two Years of Faking It at Work, and What It Predicted

Surveying healthcare workers at nursing facilities twice, two years apart, researchers found that those reporting more surface acting at baseline were at significantly higher risk of developing depressive symptoms two years later.

Why Faking a Smile All Day Can Lead to a Drink After Work

Analysing a nationally representative sample of 1,592 U.S. service workers, researchers found that surface acting was robustly linked to heavy drinking, and specifically linked to drinking after work among employees who were either naturally impulsive or had low autonomy in their job.

The Study That Separated the Two Ways of Managing Emotions at Work

Comparing employees across five distinct occupational groups, researchers found that surface acting predicted a specific burnout symptom, depersonalisation or emotional detachment from the people one serves, while genuinely trying to feel the required emotion was instead linked to a stronger sense of personal accomplishment.

The Study That Showed Chronic Caregiving Ages Cells Directly

In healthy mothers, those caring for a chronically ill child for the longest number of years had significantly shorter telomeres, lower telomerase activity, and higher oxidative stress, equivalent to roughly a decade of additional cellular ageing in the most highly stressed women.

How Years of Caregiving Wear Down the Immune System's Own Repair Cells

Comparing 41 family caregivers of Alzheimer's patients to 41 matched non-caregivers, researchers found caregivers had significantly shorter telomeres in their immune cells alongside higher depressive symptoms and altered immune signalling, pointing to a genuine biological toll of chronic caregiving stress.

Why Some Caregivers' Bodies Wear Out Faster Than Others'

In postmenopausal women, including dementia caregivers and matched non-caregivers, those whose cortisol spiked more sharply in response to a lab stress test, and whose daily cortisol pattern was flatter than the normal steep morning-to-night decline, had significantly shorter telomeres.

The Study That Showed Caregiver Strain Can Be a Matter of Life and Death

Tracking over 800 older married couples for an average of 4.5 years, researchers found that spousal caregivers who reported experiencing mental or emotional strain from caregiving had a 63% higher risk of dying than non-caregivers, while caregivers who reported no strain showed no increased mortality risk at all.

The Overlooked Cause of Menopausal Exhaustion No One Talks About

In over 2,300 women tracked across the menopause transition, those who had three or more episodes of heavy menstrual bleeding in the previous six months were 62% more likely to feel tired and 44% more likely to feel worn out, an association rarely discussed alongside hot flushes and sleep as a cause of menopausal fatigue.

How a Fluctuating Hormone Can Set Off a Stress Hormone Cascade

Tracking weekly hormone and mood measurements in 30 perimenopausal women, researchers found that sharper week-to-week increases in oestrogen were linked to higher cortisol and worse mood specifically in women with a current or past history of depression, but not in women with no such history.

The Biological Model for Why Perimenopause Hits Some Women So Much Harder

Synthesising evidence across reproductive mood research, this review proposes that fluctuating ovarian hormones during the menopause transition disrupt the brain's regulation of the stress-response system, offering a biological explanation for why some, but not all, women experience a sharp rise in depression risk during this period.

What Months of Cortisol Exposure Look Like in Menopausal Sleep

In 145 perimenopausal and postmenopausal women, higher cortisol levels measured in hair, reflecting weeks to months of exposure, were significantly associated with poorer self-reported sleep quality.

The Famous Study That Made 'Decision Fatigue' a Household Term

Analysing over 1,100 Israeli parole board rulings, researchers found the rate of favourable decisions started at roughly 65% after each break and fell close to zero by the time the next break arrived, then jumped straight back to 65% once judges had rested and eaten.

The Rebuttal That Complicated the 'Hungry Judge' Story

Interviewing court personnel and examining additional case data, the authors argued that case order in the parole hearings wasn't random, unrepresented prisoners were systematically heard last in each session, offering a non-fatigue explanation for the declining approval rate.

Could Simple Scheduling, Not Fatigue, Explain the 'Hungry Judge' Effect?

Using computer simulations built on reasonable, rational scheduling assumptions rather than any fatigue effect, this study showed that a very similar declining pattern of favourable rulings could emerge purely from how case complexity interacts with break timing.

A Steadier Signal for Decision Fatigue, in Doctors' Prescribing Pads

Analysing nearly 22,000 primary care visits for respiratory infections, researchers found doctors became 26% more likely to prescribe antibiotics, including for conditions where antibiotics are never appropriate, by the fourth hour of a clinical session compared with the first.

The Original 'Willpower Is a Muscle' Study

In a series of small lab experiments, people who had just exercised self-control on one task, such as resisting chocolate in favour of radishes, performed worse on a completely unrelated self-control task immediately afterwards, giving rise to the influential idea that willpower is a single, limited resource.

The Meta-Analysis That First Cast Doubt on Ego Depletion

Reanalysing the published ego-depletion literature while correcting for small-study and publication bias, this meta-analysis found the true underlying effect was statistically indistinguishable from zero, despite the published average appearing moderate-sized.

23 Labs Tried to Replicate Ego Depletion, and It Didn't Show Up

In a coordinated, preregistered replication involving 23 independent laboratories and over 2,100 participants using a single standardised protocol, the ego-depletion effect was found to be small and statistically indistinguishable from zero.

The Largest Test Yet of Whether Willpower Runs Out

In the largest test to date, 36 laboratories and over 3,500 participants worldwide found no reliable evidence for ego depletion, with a Bayesian analysis showing the data were four times more likely under 'no effect' than under a genuine, moderate effect.

The Heart Cost of Running on Empty

Pooling 11 prospective studies of more than 60,000 people, researchers found that vital exhaustion, a state of persistent fatigue, irritability and demoralisation, was associated with a 36% increased risk of a first heart disease event.

Why Chronic Exhaustion Is a Bigger Risk for Women's Brains Than Men's

In a cohort of over 9,000 adults, women with the highest vital exhaustion scores had more than double the risk of ischaemic stroke, while no such association was found in men.

How Chronic Exhaustion Shows Up in Your Blood, Even Without Symptoms

In over 11,500 middle-aged adults without heart disease, higher vital exhaustion was independently associated with elevated levels of three separate cardiac and inflammatory biomarkers, and the combination of severe exhaustion with elevated biomarkers predicted the highest risk of future cardiovascular events.

The Full Body of Evidence on Chronic Exhaustion and Heart Disease

Pooling 13 prospective studies covering more than 52,000 people, this review found vital exhaustion was associated with a 50% increased risk of coronary heart disease in healthy populations, and roughly double the risk of a repeat cardiac event in people who already had heart disease.

Mindfulness Meditation Outperforms Standard Sleep Advice in Older Adults

In 49 older adults with sleep disturbances, six weeks of structured mindfulness meditation training improved sleep quality, insomnia symptoms, depression symptoms and fatigue more than standard sleep hygiene education.

Does Mindfulness Meditation Actually Beat Other Ways to Improve Sleep?

Pooling 18 trials and over 1,600 participants, researchers found mindfulness meditation significantly improved sleep quality compared with generic control activities, but showed no advantage over established, specific sleep treatments such as cognitive behavioural therapy for insomnia.

How Mindfulness Meditation Compares With Exercise for Sleep

In 413 healthy adults aged 30 to 69 with no prior sleep problems, both an eight-week mindfulness-based stress reduction course and matched moderate-intensity exercise training improved sleep quality over seven months compared with a wait-list control, with neither approach clearly outperforming the other.

Who Benefits Most From Mindfulness Training for Sleep

In 200 older adults, an eight-week mindfulness-based stress reduction programme improved overall sleep quality compared with a wait-list control, with the largest benefit seen in those who had the most disturbed sleep to begin with.

Testing Magnesium as a Treatment for Insomnia in Older Adults

In 46 elderly adults with insomnia, eight weeks of daily magnesium supplementation significantly improved sleep time, sleep efficiency, and blood markers linked to sleep regulation compared with placebo.

What the Evidence Actually Says About Magnesium for Sleep

Pooling the only three randomised trials that exist on the topic, this review found magnesium supplementation shortened the time it took older adults to fall asleep by around 17 minutes, but the overall quality of the underlying evidence was rated low to very low.

A Fresh Trial on Magnesium for Everyday Poor Sleepers

In 31 adults with average age 46 and non-clinical poor sleep, two weeks of daily magnesium supplementation improved sleep quality and mood compared with placebo, with each participant tested on both conditions.

Food-Based Magnesium Versus the Supplement: What Actually Tracks With Better Sleep

Analysing nearly 22,000 adults, researchers found that higher dietary magnesium intake from food was independently linked to normal sleep duration, but magnesium taken as a supplement showed no such association.

Why Sleeping In Doesn't Undo a Week of Short Sleep

In a controlled two-week study, adults who slept only five hours on weeknights but were allowed unlimited weekend sleep showed no metabolic improvement over those who were sleep-restricted throughout, and in some measures, their insulin sensitivity was worse.

How Many People Actually Catch Up on Sleep Debt? Not Many

In a representative sample of over 12,000 French adults, more than one in three were short sleepers, and among those with the most severe weekday sleep debt, roughly three in four did not manage to compensate for it through napping or weekend catch-up sleep.

Does Weekend Catch-Up Sleep Actually Protect Your Heart? A Large Study Says No

Tracking over 73,000 UK adults' sleep with wrist accelerometers for eight years, researchers found that weekend catch-up sleep was not associated with a reduced risk of death or cardiovascular disease, contradicting earlier, smaller studies based on self-reported sleep.

One Place Weekend Catch-Up Sleep Might Actually Help

In 215 adults aged 65 and older, those who got weekend catch-up sleep, measured by both sleep diary and accelerometer, had roughly 73 to 74% lower odds of showing signs of cognitive dysfunction than those who didn't.

The Case Reports That Named 'Orthosomnia'

Describing three patients who sought treatment for self-diagnosed sleep problems based entirely on their sleep tracker data, researchers coined the term 'orthosomnia' for a perfectionistic pursuit of ideal sleep numbers that can itself worsen sleep.

How Common Is Sleep-Tracker Anxiety, Actually?

In a general population sample of 523 adults, between 3% and 14% met criteria for orthosomnia depending on how strictly it was defined, and those who did had significantly more severe insomnia symptoms than those who didn't.

Why the Numbers Making You Anxious Might Not Be Accurate

Pooling data across multiple validation studies, researchers found that wristband Fitbit devices consistently overestimated total sleep time and sleep efficiency, and underestimated time spent awake, compared with clinical polysomnography.

The New Scale for Measuring an Unhealthy Obsession With Sleep

Surveying nearly 1,000 adults, researchers developed and validated the first purpose-built questionnaire for orthosomnia, identifying two distinct components: how much sleep worry interferes with daily life, and a rigid, all-or-nothing mindset about achieving perfect sleep.

How the Body Clock's Monthly Hormone Swing Shows Up in Sleep

In 20 women in the early menopausal transition, sleep was measurably more disrupted in the progesterone-rich luteal phase than the follicular phase, with more awakenings and less deep sleep, whether or not the woman had insomnia.

The Hormone Shift That Predicts a Rougher Night's Sleep

In 27 premenopausal women, a steeper rise in progesterone from the follicular to the mid-luteal phase was linked to significantly more fragmented sleep, measured objectively, offering the first direct evidence connecting the pace of this hormonal shift to disrupted sleep.

Why the Follicular Phase Can Leave You Sharper or Duller Overnight

In 16 premenopausal women kept awake for over two days in a laboratory, those in the follicular phase performed measurably worse on overnight attention and reaction-time tasks than those in the luteal phase, an effect driven by core body temperature rather than the sex hormones directly, and one that light exposure could reverse.

Why PMS Can Feel Like Bad Sleep Even When the Data Says Otherwise

In 18 women with severe premenstrual syndrome compared with 18 controls, those with PMS reported significantly worse sleep quality in the premenstrual phase, but objective sleep recordings showed no corresponding disruption specific to PMS, an effect that tracked closely with anxiety levels rather than measurable sleep.

How Your Sleep Habits Predict Your Vaccine Response

In 125 adults aged 40 to 60 tracked with wrist actigraphy, those who slept fewer hours in the natural course of their lives produced a weaker antibody response to the hepatitis B vaccine and were less likely to be fully protected six months later.

Why Short Sleepers Catch More Colds

In 164 adults whose sleep was tracked objectively for a week before deliberate exposure to a cold virus, those sleeping six hours or less a night were roughly four times more likely to develop a confirmed cold than those sleeping seven hours or more.

The Evidence Linking Sleep to How Well Vaccines Actually Work

Pooling data across multiple studies, researchers found that objectively measured short sleep around the time of vaccination was associated with a substantially weaker antibody response, though the effect was clearly established in men and did not reach statistical significance in women, likely reflecting too few studies rather than a true absence of effect.

What Your Sleep Pattern Does to Whole-Body Inflammation

Pooling 72 studies and more than 50,000 people, researchers found that sleep disturbance and unusually long sleep, more than eight hours, were both associated with higher levels of inflammatory markers linked to cardiovascular disease and diabetes, while short sleep duration alone showed a weaker, less consistent link.

The Study That Put a Number on 'Beauty Sleep'

In 60 premenopausal women, poor sleepers showed more signs of skin ageing, including fine lines and reduced elasticity, and recovered more slowly from sun exposure and skin barrier disruption than good sleepers.

The Study That Gave 'Beauty Sleep' Its Scientific Backing

When 65 independent observers rated photographs of the same people after a normal night's sleep and after sleep deprivation, the sleep-deprived photos were consistently rated as less healthy, less attractive, and more tired.

What Other People Actually Notice When You're Sleep-Deprived

Following up on earlier 'beauty sleep' findings, this study identified the specific visible cues, hanging eyelids, red and swollen eyes, dark circles, pale skin, and downturned mouth corners, that observers actually associate with a night of lost sleep.

What Six Nights of Short Sleep Does to Skin in Your Forties

In 32 Korean women in their forties, restricting sleep to four hours a night for six nights significantly worsened skin hydration, elasticity, gloss, and the visible depth of crow's feet and frown lines, with hydration declining from the very first night.

Does Melatonin Actually Help With Jet Lag?

A Cochrane review of ten trials found that melatonin taken at the destination bedtime significantly reduced jet lag symptoms after crossing five or more time zones, with the benefit greatest when flying eastward and over more time zones.

How to Start Adjusting to a New Time Zone Before You Even Fly

In 26 young adults, gradually advancing bedtime by one to two hours a day for three days before a simulated eastward flight, combined with timed morning bright light, shifted the body clock by up to several hours before travel even began.

What Eastward Travel Costs You, According to the NBA

Analysing 11,481 NBA games across ten seasons, researchers found that teams experiencing jet lag from eastward travel performed measurably worse at their own home games, with a reduced chance of winning, fewer points, and fewer rebounds, an effect not seen with westward travel.

The Full Picture on Jet Lag, and What Actually Helps

This comprehensive review distinguishes jet lag, caused by circadian misalignment, from simple travel fatigue, and concludes that behavioural strategies, timed light exposure, sleep scheduling, and selective use of melatonin, are better supported than sedatives or stimulants for easing the transition.

What Actually Happens to Sleep When You Share a Bed

In twelve young couples studied with simultaneous overnight brainwave monitoring, sharing a bed with a partner increased REM sleep by around ten percent and made it less fragmented compared with sleeping alone, with sleep stages between partners becoming measurably synchronised.

Why Co-Sleeping Can Cost Women More Than Men

Tracking ten couples over 28 nights at home, researchers found that sharing a bed measurably reduced women's objective sleep efficiency, while men's sleep efficiency was unaffected by their partner's presence unless sexual contact occurred.

What Having a Steady Partner Is Linked to in Midlife Women's Sleep

In 367 women followed through midlife, those with a consistent partner over six to eight years had better objectively measured sleep continuity than women who were unpartnered, gained a partner, or lost one, even after accounting for other health and demographic factors.