A new study led by Professor Jan de Jonge, a work and sports psychologist at Eindhoven University of Technology in the Netherlands (and Adjunct Professor at the University of South Australia), found that insufficient and poor-quality sleep significantly increases the chance of getting hurt while running.

In a survey of 425 recreational runners, the researchers discovered that participants who reported shorter sleep duration, lower sleep quality, or frequent sleep problems were almost twice as likely to experience an injury compared to those who slept well.

The results, published in Applied Sciences, provide what Prof de Jonge calls "compelling evidence that sleep is a critical yet often overlooked component of injury prevention."

"While runners specifically focus on mileage, nutrition and recovery strategies, sleep tends to fall to the bottom of the list," he explains. "Our research shows that poor sleepers were 1.78 times more likely to report injuries than those with stable, good quality sleep, with a 68% likelihood of sustaining an injury over a 12-month period. That's a strong reminder that how well you rest is just as important as how hard you train."

Sleep: The Missing Element in Runner Recovery

Recreational running remains one of the most popular sports worldwide, yet it carries a substantial risk of injury. Studies estimate that up to 90% of runners will be injured at some point, resulting in millions of dollars lost each year in medical bills and missed work.

Prof de Jonge's team took a comprehensive approach, examining sleep not only in terms of duration but also quality and disorders. This broader view helped identify how different aspects of sleep contribute to physical vulnerability.

"Sleep is a vital biological process that allows the body and mind to recover and adapt to the physical and mental demands of training," says Prof de Jonge. "When sleep is disrupted or insufficient, the body's ability to repair tissues, regulate hormones and maintain focus diminishes, all of which can increase injury risk."

The study revealed that runners who struggled with falling asleep, woke up frequently during the night, or rarely felt rested were the most prone to injury. In contrast, those who maintained consistent sleep schedules and felt well-rested reported significantly fewer injuries.

Rethinking Training: Why Sleep Deserves Equal Priority

Prof de Jonge emphasizes that the research carries important lessons for both recreational and competitive runners, as well as for coaches and health professionals.

"We often assume that more training equals better performance, but that's not necessarily the case," he notes. "Runners (especially those balancing training with work, family and social commitments) may actually need more sleep than average adults to recover properly. Sleep should be treated as a performance priority, not an afterthought."

Experts generally recommend seven to nine hours of sleep per night, though athletes often benefit from additional rest, including short naps, to enhance both physical and mental recovery.

To improve sleep quality, consistent bedtimes, limiting screen use before sleep, reducing caffeine and alcohol, and maintaining a quiet, cool environment are all advised.

"Sleep quality and sleep duration are both important, but quantity often provides the bed-rock," Prof de Jonge concludes. "Sleep should be recognized not only as a recovery tool, but also as a potential predictor of injury vulnerability in recreational sports."

The study, "Sleep Matters: Profiling Sleep Patterns to Predict Sports Injuries in Recreational Runners," was published in Applied Sciences.

The results indicate that even after treatment, the nerves of Alzheimer's disease (AD) patients remain damaged and the brain's natural waste-removal ability does not recover quickly. This finding highlights the disease's complexity and the need for therapies that target more than one biological pathway at once.

Alzheimer's Disease: A Complex and Multifactorial Disorder

The study adds to growing evidence that Alzheimer's is a multifaceted disease. It is the most common form of neurodegenerative disorder, yet remains one of the most difficult to treat because it develops through several overlapping causes.

One major contributor to nerve cell damage in AD is the buildup of the protein amyloid-β (Aβ) in the brain. In healthy individuals, a network called the glymphatic system circulates cerebrospinal fluid through spaces around arteries into brain tissue. There, it mixes with interstitial fluid to remove metabolic waste, including Aβ. The term "glymphatic" comes from the glial cells that play a key role in this process.

How Alzheimer's Disrupts the Brain's Cleanup System

In people with Alzheimer's, Aβ accumulates and causes arteries to stiffen, slowing the flow of fluids between brain tissue and cerebrospinal fluid. This disruption blocks the brain's ability to clear out waste, setting off a cascade of damaging neurodegenerative effects that lead to the symptoms of the disease.

Lecanemab, a recently approved antibody therapy, is designed to reduce the buildup of amyloid-β. To test its effects, the Osaka Metropolitan University team examined the glymphatic system in patients before and after receiving lecanemab treatment. They used a specialized imaging measure known as the DTI-ALPS index to track changes.

No Short-Term Improvement Detected

Despite expectations, the researchers found no significant difference in the DTI-ALPS index between pre-treatment and three months after therapy.

They concluded that while anti-amyloid drugs like lecanemab can lower plaque levels and slow cognitive decline, they may not be enough to restore lost brain function. By the time symptoms appear, both neuronal damage and waste clearance impairments are likely well established and difficult to reverse. This underscores how Alzheimer's involves a network of biological problems, not just plaque buildup.

Next Steps: Understanding Why the Brain Doesn't Recover

"Even when Aβ is reduced by lecanemab, impairment of the glymphatic system may not recover within the short-term," Oura said. "In the future, we want to look at factors like age, the stage of the disease, and degree of lesions in the white matter to further understand the relationship between changes in the glymphatic system due to lecanemab treatment and the outcome of treatment. This will help understand the best way to administer treatment to patients."

The research was published in the Journal of Magnetic Resonance Imaging.