High intensity interval training (HIIT) may be the optimal exercise for reducing body fat while maintaining muscle mass in older adults, according to new research led by Australian academics.
“We found that high, medium and low intensity exercises all led to modest fat loss but only HIIT retained lean muscle,” said lead author and exercise physiologist Dr Grace Rose of the University of the Sunshine Coast.
The study examined how the intensity of different exercises could influence body composition in healthy older adults.
“While moderate training reduced fat mass, it also caused a small decline in lean muscle,” she said. “Both high and moderate intensities improved the composition of weight carried around the middle. Further analysis is needed of the low intensity results.” Dr Rose said the findings were particularly useful because body composition was implicated in the progression of many chronic diseases as people aged.
More than 120 healthy older adults from the Greater Brisbane region participated in the study, completing three exercise sessions a week in the gym for six months.
Their average age was 72 years old and average body mass index was 26kg/m2, categorised as normal for people aged over 65.
UniSC Associate Professor of Physiology and co-author Mia Schaumberg welcomed the the paper published in the journal Maturitas, with collaborators including UniSC’s Healthy Ageing Research Cluster and The University of Queensland.
“High intensity training in this study involved repeated short bursts, or intervals, of very hard exercise – where breathing is heavy and conversation is difficult – alternated with easier recovery periods. More than 120 healthy older adults from the Greater Brisbane region participated in the study, completing three exercise sessions a week in the gym for six months.
Their average age was 72 years old and average body mass index was 26kg/m2, categorised as normal for people aged over 65.
UniSC Associate Professor of Physiology and co-author Mia Schaumberg welcomed the timing of the paper published in the journal Maturitas, with collaborators including UniSC’s Healthy Ageing Research Cluster and The University of Queensland.
“High intensity training in this study involved repeated short bursts, or intervals, of very hard exercise – where breathing is heavy and conversation is difficult – alternated with easier recovery periods,” she said.
“HIIT likely works better because it puts more stress on the muscles, giving the body a stronger signal to keep muscle tissue rather than lose it.”
Two specific weather patterns have been identified as capable of increasing the risk of headaches and migraines, thanks to physicians at the University of CincinnatiCollege of Medicine, along with researchers at the Icahn School of Medicine at Mount Sinai, Errex Inc. and Teva Pharmaceuticals.
Headaches and migraines are often associated with weather variables such as barometric pressure, precipitation, humidity and temperature. As weather patterns vary around the world, evidence suggests their impacts vary across geographic regions, seasons and population groups.
For this study, researchers analysed weather patterns in the Northeast U.S. to determine whether any are associated with new-onset headaches in patients with episodic migraines.
“What is significant about this headache research is that we are one of the first to look at weather patterns with a combination of variables, instead of a single weather variable,” said Martin. “We further examined those weather patterns by region and season.”
Which weather patterns are linked to higher headache risk?
They found that two specific weather patterns were associated with a higher risk of new-onset headaches in the Northeastern region. One is an approaching cold front, or low-pressure system, with precipitation, which can occur in all seasons. The other is the Bermuda High, a high-pressure system that heavily dictates summer weather across the eastern half of the U.S.
“This is one of the first studies to more closely implicate frontal passage in the onset of headache,” said Al Peterlin, a co-investigator and meteorologist from Errex Inc.
This is one of the first studies to suggest that a preventive medication might reduce the likelihood of a weather-associated headache.
Brinder Vij, MDLead author, professor of clinical medicine & director of the Division of Headache Medicine in the Department of Neurology and Rehabilitation Medicine
To determine their findings, researchers compared thousands of daily headache diary entries from participants at the Northeastern U.S. sites of the HALO-EM and HALO-LTS studies, both randomised, double-blind, placebo-controlled Phase 3 clinical trials that established the safety and efficacy of the prescription medication fremanezumab (Ajovy) for the preventive treatment of episodic migraines. They linked the headache data to daily meteorological data from the National Climatic Data Center, tracking four years of weather patterns organised into three-day windows.
Researchers also confirmed that at least six months of treatment with fremanezumab significantly reduced the rate of new-onset headaches compared with no medication across all weather patterns, including conditions considered high risk for new headache onset.
“We saw the weather and headache relationship wiped out with the use of this medication,” said Fred Cohen, MD, a co-investigator and faculty member at Icahn School of Medicine at Mount Sinai. “We started to notice its effectiveness as early as one month after the start of the medication.”
“This is one of the first studies to suggest that a preventive medication might reduce the likelihood of a weather-associated headache,” said lead author Brinder Vij, MD, a professor of clinical medicine and director of the Division of Headache Medicine in the Department of Neurology and Rehabilitation Medicine.
He further stated that this study offers new hope for the millions of people with migraine experiencing weather-associated headaches.
To understand what might explain the paradox, my colleagues and I conducted a study that directly compared sleep quality ratings and objective sleep measures between men and women.
We found that women complained more of sleep problems – but slept objectively much better than men. We think this paradox can probably be explained by men overestimating their sleep quality as they’re less able to perceive how often they wake up at night.
A total of 238 randomly selected women participated in the study, plus 238 men who were matched on age and BMI with the women to ensure similar participants were compared against each other.
Sleep was recorded in each participant’s home using a recorder that measured brain waves (electroencephalography – EEG), muscle tension (electromyography – EMG) and eye movements (electrooculography – EOG). These devices tracked what stage of sleep a participant was in and for how long, how much time they spent awake and how quickly they fell asleep.
A researcher visited the participant’s home in the evening, mounted the recording equipment and left. The participant went to bed and awoke at their usual time.
In the morning, the participant rated the degree of difficulty they had falling asleep, if their sleep was restless, if they woke up early, how often they thought they’d woken up, how long it took them to fall asleep, how long they slept and their overall sleep quality.
The sleep recording was scored by a sleep technician based on visual inspection of the EEG, EOG and EMG recordings. The data was then analysed to understand the objective quality of each participant’s sleep and its relation to gender and age.
Analyses were also adjusted for factors such as gender, age and alcohol consumption and smoking, which may affect sleep.
Sleep quality
The results show that women subjectively reported significantly lower sleep quality than men. Yet women actually had considerably fewer nighttime awakenings, less stage one (superficial) sleep and higher sleep efficiency (they spent more time asleep while in bed). Women also experienced more stage three (deep) sleep and slept longer (400 minutes versus 382 minutes for men).
When women did wake up at night, they spent more time awake on average. Photo by Cottonbro on Pexels
The results suggest that women objectively had a good nights’ sleep, compared to men. The only variable that suggests worse sleep in women was that when they did wake up at night, they spent more time awake than men did – around nine minutes each time for women versus just under seven minutes for men.
It only takes around five minutes of being awake at night for a person to remember it the next morning. This may explain why women were better able to remember if they’d woken up the night before and estimate how many times they had. Men, on the other hand, grossly underestimated their number of awakenings (by 72% compared to women’s 37%).
For other quantitative measures, like time to fall asleep, sleep duration and time awake, men and women were equally good at estimating their objective values. And they were relatively correct.
We took this further and found that men who only woke up for a short period of time during the night (around eight minutes or so each time they woke up) often didn’t remember they had.
When this group of men was removed, no gender difference in subjective sleep quality remained. This suggests that men with short nighttime awakenings report better sleep quality than would be expected from their objective sleep measures as they didn’t remember they’d woken up.
It’s also noteworthy that men’s objective sleep deteriorated faster with age than women. This was particularly obvious for stage three sleep. While women aged over 65 got around 80 minutes of stage three sleep each night, men had only 53 minutes. Among those between 30 and 50 years of age, the amount was similar for men and women (around 70 minutes).
Sleep and wellbeing
A key reason women may complain of having a worse nights’ sleep than they objectively had may therefore be the amount of time they spent awake when they woke up, making it easier for them to notice. Likewise, men may overestimate their sleep quality because they’ve spent less time awake when they’ve woken up, so they don’t remember it happening.
Both findings would work towards reducing subjective sleep quality in women and increasing it in men. We assume then, that the experience of awakenings has an important influence on subjective sleep quality.
As our study was only conducted over one night, it will be important for future research to investigate whether these findings remain when participants are studied over longer periods of time.
Future studies may also want to explore the reasons for poor sleep in men – especially since common sources of disturbed sleep, such as alcohol, smoking and BMI, were all adjusted for in our analysis. Researchers may also want to investigate why men’s sleep becomes objectively worse as they get older.
Our research illustrates how sleep quality doesn’t just involve the physiological aspects of sleep. It also includes our own subjective experiences, which can impact our wellbeing and how rested we feel.
It also suggests that because many men overestimate their sleep quality, they may also overlook any sleep problems they’re experiencing. This could mean that some men aren’t getting help for conditions that could be affecting their health and wellbeing.
Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are widely prescribed for diabetes and obesity, but studies have found evidence that the medications may also influence behaviour, such as supporting impulse control and reducing substance use and alcohol consumption by potentially interacting with the brain’s reward and stress systems. New research in Criminologyadds to this growing evidence.
When investigators analysed data from a 2025 nationally representative US survey involving 821 adults who had ever used GLP-1 medications, they found that while impulsivity and alcohol use were strongly associated with committing violent crime, these associations were significantly weaker among current GLP-1 RA users compared with former users. So even when a GLP-1 RA user drinks or acts impulsively, the situation is less likely to escalate into engaging in violent criminality. More thorough analyses showed that this finding was especially consistent related to impulsivity, but less so with alcohol use.
The findings suggest that GLP-1 RAs may lessen the extent to which certain established risk factors translate into violent behavior.
“As GLP-1 medications become increasingly widespread, understanding their broader behavioral effects becomes an important public health and criminological question that requires careful study,” said corresponding author Daniel C. Semenza, PhD, of Rutgers University.
New research suggests Alzheimer’s disease may affect the brain’s ability to adapt before memory problems become obvious, offering clues for earlier interventions.
When most people think about Alzheimer’s disease, memory loss is usually the first thing that comes to mind. Forgetting a loved one’s name, missing appointments or repeatedly misplacing everyday items are often considered early warning signs.
But what if the disease begins affecting the brain long before memory problems become noticeable? New research from scientists at Texas A&M Health suggests that another change in brain function may appear even earlier: difficulty adapting when circumstances change.
In a recent study, researchers found that animal models with Alzheimer’s-related brain changes developed problems with cognitive flexibility months before they showed signs of memory impairment. Cognitive flexibility refers to the brain’s ability to adjust behavior, learn new rules and adapt when situations change.
“We found that this function was impaired before we could detect deficits in spatial memory,” said neuroscientist Jun Wang, PhD, professor in the Texas A&M University Naresh K. Vashisht College of Medicine at Texas A&M Health.
The findings suggest memory loss is not always the earliest sign of Alzheimer’s disease. Instead, they suggest that by the time memory problems become noticeable, disease-related brain changes may already be underway. Paying attention to earlier changes in executive function may provide additional clues about the earliest stages of the disease.
Testing the brain’s ability to adapt
To investigate these early changes, researchers used a widely studied animal model of Alzheimer’s disease known as 5xFAD. These models develop amyloid-beta plaques, one of the key features found in the brain of humans with Alzheimer’s disease.
The research team focused on measuring cognitive flexibility through a method called reversal learning. In this type of test, animal models first learn that a particular action leads to a reward. Once that association is established, researchers change the rules and reward a different action instead.
Healthy animal models quickly adjusted and learned the new rule. 5xFAD models struggled to adapt, continuing to follow the original rule even after it no longer led to a reward. What made the finding particularly significant was that although they struggled to adapt to change, the animal models still performed normally on tests of spatial memory, which is the ability to remember where things are and helps us navigate our surroundings.
A hyperactive brain circuit
The researchers then discovered abnormally high activity in the medial prefrontal cortex, the region involved in decision-making, behavioral flexibility and goal-directed actions. This hyperactivity extended through a network connecting the prefrontal cortex and the striatum, two brain regions that work together to help people adjust their behaviour when circumstances change.
The team also found reduced activity in a specialised group of brain cells called cholinergic interneurons. These cells play an important role in learning and behavioral adaptation, and their decreased activity closely matched the cognitive flexibility deficits observed in the animal models.
Together, the findings suggest that Alzheimer’s disease may affect neural circuits involved in executive function and adaptability before causing noticeable memory problems.
Breaking a harmful cycle
Scientists have known that amyloid-beta production increases when neurons are highly active. At the same time, amyloid-beta can make neurons even more excitable. This creates a potentially harmful cycle in which increased brain activity promotes amyloid accumulation, which then drives even more activity.
Wang describes this cycle as a “chicken-and-egg” problem. To test whether breaking this cycle could help, the researchers used a targeted approach to quiet the overactive brain pathway. The method worked like a temporary “dimmer switch,” allowing the team to reduce the activity of selected brain cells in the front part of the brain that send signals to the striatum, a region involved in flexible behaviour.
The intervention improved cognitive flexibility, restored more normal patterns of brain activity and reduced amyloid-beta accumulation. The benefits persisted after treatment ended, suggesting lasting changes within the affected neural circuits.
Implications for Alzheimer’s research
Although the study was conducted in animal models and further research is needed to determine whether the same pattern occurs in humans, the findings point to a promising new direction for Alzheimer’s research and potential future treatments.
Rather than focusing exclusively on memory loss, scientists may need to pay closer attention to early changes in cognitive flexibility and executive function that may provide clues that Alzheimer’s-related changes are already underway. The findings also suggest that abnormal brain activity may be more than just a consequence of the disease. Reducing activity in the overactive brain circuit improved cognitive flexibility and reduced amyloid-beta accumulation, suggesting that targeting these neural networks could help slow disease progression.
Wang is hopeful that if future research confirms these findings, cognitive flexibility tests could potentially complement existing diagnostic evaluations. That may help identify people at earlier stages of the disease, perhaps years before more obvious memory symptoms appear.
“One thing that most people in the field agree on is that early diagnosis is extremely important,” Wang said. “Alzheimer’s disease is progressive. Neurons continue to degenerate over time. If we can identify the disease earlier, then treatment has a much better chance of helping.”
