Monday, July 07, 2025

 

Everything we thought about running injury development was wrong, Danish study shows




Study with over 5,200 runners shows that running injuries do not develop gradually over time – but most often occur during a single running session.

Millions of runners are therefore receiving incorrect guidance from sports watches, researcher warns.



Aarhus University





A new study from Aarhus University turns our understanding of how running injuries occur upside down.

The research project, which is the largest of its kind ever conducted, shows that running-related overuse injuries do not develop gradually over time, as previously assumed, but rather suddenly – often during a single training session.

"Our study marks a paradigm shift in understanding the causes of running-related overuse injuries. We previously believed that injuries develop gradually over time, but it turns out that many injuries occur because runners make training errors in a single training session," explains Associate Professor Rasmus Ø. Nielsen from the Department of Public Health at Aarhus University, who is the lead author of the study.

The study followed 5,205 runners from 87 countries over 18 months and shows that injury risk increases exponentially when runners increase their distance in a single training session compared to their longest run in the past 30 days. The longer the run becomes, the higher the injury risk.

Incorrect guidance for millions of runners

According to Rasmus Ø. Nielsen, the results cast critical light on how the tech industry has implemented so-called "evidence." Millions of sports watches worldwide are equipped with software that guides runners about their training – both for training optimization and injury prevention.

However, the algorithm used for injury prevention is built on very thin scientific grounds, according to Rasmus Ø. Nielsen.

"This concretely means that millions of runners receive incorrect guidance from their sports watches every day. They think they are following a scientific method to avoid injuries, but in reality they are using an algorithm that cannot predict injury risk at all," he says.

 

 

Non-existing evidence behind guidance

The current algorithm, called "Acute:Chronic Workload Ratio" (ACWR), was introduced in 2016 and is now implemented in equipment from companies that produce sports watches, while organizations and clinicians, such as physiotherapists, also use the algorithm.

The ACWR algorithm calculates the ratio between acute load (last week's training) and chronic load (average of the past 3 weeks). The algorithm recommends a maximum 20% increase in training load to minimize injury risk.

According to Rasmus Ø. Nielsen, the algorithm was originally developed for team sports and was based on a study with 28 participants. Due to the few participants in the study combined with data manipulation, the evidence base for using the algorithm to prevent running injuries is therefore "non-existent."

Realtime guidance

The research team has therefore worked for the past eight years to develop a new algorithm that will be much better at preventing injuries for runners.

Rasmus Ø. Nielsen emphasizes that he and the other researchers behind the study have no commercial interests in launching a new algorithm as a potential replacement for a method he himself criticizes.

The algorithm will be made freely available to runners, companies, clinicians and organizations who can use it actively to guide training and injury prevention.

Rasmus Ø. Nielsen hopes that the new insights will be implemented in existing technology.

"I imagine, for example, that sports watches with our algorithm will be able to guide runners in real-time during a run and give an alarm if they run a distance where injury risk is high. Like a traffic light that gives green light if injury risk is low; yellow light if injury risk increases and red light when injury risk becomes high," explains Rasmus Ø. Nielsen.

 

Facts about the study

The Garmin-Runsafe Running Health Study followed 5,205 runners from 87 countries over 18 months.

Participants recorded 588,071 running sessions, and 35 percent of participants sustained a running-related injury during the study.

The study documents concrete risk increases with increased running distances compared to the longest run in the past 30 days: 

10-30 percent increase: 64 percent increased injury risk

30-100 percent increase: 52 percent increased injury risk

Over 100 percent increase: 128 percent increased injury risk

The study also shows that injury risk increases with progressions over 1 percent (in the interval between 1 and 10 percent), which questions whether the frequently used 10% rule for safe training progression is accurate.

 

About the research results

Study type: Cohort study with 18 months follow-up period

Collaborators: Garmin International (participant recruitment) and researchers from Denmark, Sweden, Luxembourg and Australia.

External funding: The study received external funding from Aarhus University Research Foundation and the Danish Rheumatism Association. Garmin and external funders had no influence on study design, research questions, data collection, data processing and statistical analysis and/or interpretation of data as well as the writing and publication process.

Conflict of interest: None

Link to scientific article: How much running is too much? Identifying high-risk running sessions in a 5200-person cohort study | British Journal of Sports Medicine

Plate tectonics – Mineral olivine is crucial for heat transport in the mantle




University of Potsdam
subducting slab 

image: 

Sketch of subducting slab and transport of water-bearing minerals to the Mantle Transition Zone

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Credit: Enrico Marzotto





Due to the radiative thermal conductivity of the mineral olivine, only oceanic plates over 60 million years old and subducting at more than 10 centimeters per year remain sufficiently cold to transport water into the Earth's deep mantle. This was found by scientists from the University of Potsdam and from the Helmholtz Centre for Geosciences (GFZ) Potsdam, together with international colleagues, by measuring the transparency of olivine under conditions in Earth’s mantle for the first time. Their results were published in the journal “Nature Communications”.

The outer layer of our planet, the lithosphere, is fragmented into several rigid plates, which are drifting on top of the warm and relatively soft mantle. The collision between plates causes the heavier plate to sink into the Earth's mantle. This sinking process takes the name of ‘subduction’, while the subducting plate is called ‘slab’. Usually, the oceanic lithosphere is heavier than the continental one, because it is made of denser minerals like olivine, which accounts for 80 percent of the oceanic lithosphere. Olivine is also the predominant mineral in the Earth's outer shell, representing 60% of the upper mantle (40-410 km of depth). While subducting, the cold slabs are progressively heated by the warm ambient mantle through heat diffusion, a process that involves heat conduction and heat radiation. Understanding slab heating processes is fundamental to explaining the occurrence of deep earthquakes, and the presence of water at more than 600 km of depth.

“We measured, for the first time, the transparency of olivine inside the Earth,” says geodynamicist Enrico Marzotto from the Institute of Geosciences of the University of Potsdam. “These measurements demonstrate that olivine is infrared transparent even at the extreme pressure and temperature conditions of Earth’s interior.” The heat transport by radiation accounts for approximately 40 percent of the total heat diffused in the olivine-rich upper mantle. Therefore, radiative thermal conductivity plays an important role in slab heating and can have far-reaching effects on the density and the rigidity of the subducting plates, and their capacity to carry water into Earth’s interior.

With two-dimensional slab thermal evolution models the team could show that the rapid heating enhanced by radiative heat transport induces the breakdown of water-bearing minerals at shallower depth. “This could potentially explain the occurrence of earthquakes in the slab at more than 70 kilometers of depth,” says Marzotto. “Consequently, only slabs that are more than 60 Million years old and sinking faster than 10 centimeters per year, remain sufficiently cold to transport the water-bearing minerals down to the Mantle Transition Zone (MTZ) in 410 to 660 kilometers depth.” The MTZ is considered the largest water reservoir on our planet, potentially containing up to three times more water than the Earth's oceans.

“Our study also provides numerical tools to compute the lifetime of thermal anomalies in the mantle and their geodynamic behavior,” adds Enrico Marzotto. These anomalies can be hot (like the plumes rising from the Earth's deep mantle) or cold (like the subducting slabs).

 

Link to Publication: Marzotto, E., Koptev, A., Speziale, S. et al. Olivine’s high radiative conductivity increases slab temperature by up to 200K. Nat Commun 16, 6058 (2025). https://doi.org/10.1038/s41467-025-61148-8

 

 Image: Sketch of subducting slab and transport of water-bearing minerals to the Mantle Transition Zone. Visualisation: Enrico Marzotto.

 

 Journal

 

Researchers found a better way to teach large language models new skills




North Carolina State University





Researchers have developed a technique that significantly improves the performance of large language models without increasing the computational power necessary to fine-tune the models. The researchers demonstrated that their technique improves the performance of these models over previous techniques in tasks including commonsense reasoning, arithmetic reasoning, instruction following, code generation, and visual recognition.

Large language models are artificial intelligence systems that are pretrained on huge data sets. After pretraining, these models predict which words should follow each other in order to respond to user queries. However, the nonspecific nature of pretraining means that there is ample room for improvement with these models when the user queries are focused on specific topics, such as when a user requests the model to answer a math question or to write computer code.

“In order to improve a model’s ability to perform more specific tasks, you need to fine-tune the model,” says Tianfu Wu, co-corresponding author of a paper on the work and an associate professor of computer engineering at North Carolina State University. “However, these models are so large that it is not feasible to re-train the entire model. Instead, you want to determine the smallest number of changes necessary to improve the model’s performance. We’ve developed a technique, called WeGeFT (pronounced wee-gift), that represents a significant advance for fine-tuning these large models.”

The big break-through for fine-tuning these large models was called LoRA, which came out in 2022. LoRA works by using mathematical tools to identify a small subset of key parameters that are most likely to improve a model’s performance on a specific task. There have been many attempts to improve upon LoRA, but Wu and his collaborators found these previous efforts either required significantly more computational power to improve performance, or used the same amount of computing power without improving performance.

“WeGeFT builds on LoRA, but incorporates additional mathematical tools that allow us to determine which of the key parameters the model is already familiar with and which parameters the model would need to ‘learn,’” says Wu. “By placing more weight on the truly novel parameters, we are able to improve model performance compared to LoRA without incorporating significant new computational demands.”

In proof-of-concept testing, the researchers found that WeGeFT performed as well as or better than LoRA and its many variants across a variety of downstream tasks: commonsense reasoning, arithmetic reasoning, instruction following, code generation, and visual recognition.

“We think this is a valuable step forward,” Wu says. “We are now exploring ways that WeGeFT could also be used to identify elements of the model that are responsible for harmful outputs, with the goal of improving AI alignment and ‘surgery’ to improve model safety and outputs. We expect that work to be forthcoming.”

The paper, “WeGeFT: Weight-Generative Fine-Tuning for Multi-Faceted Efficient Adaptation of Large Models,” will be presented July 17 at the International Conference on Machine Learning, being held in Vancouver, Canada. Co-corresponding author of the paper is Chinmay Savadikar, a Ph.D. student at NC State. The paper was co-authored by Xi Song, an independent researcher.

This work was done with support from the National Science Foundation under grants 1909644, 2024688 and 2013451; and from the Army Research Office under grants W911NF1810295 and W911NF2210010.

 

Mediterranean bacteria may harbor new mosquito solution




American Society for Microbiology




Highlights:

  • Mosquitoes that carry pathogens often develop resistance to insecticides.
  • Biopesticides offer an ecologically friendly way to control the pests and mitigate resistance, but options are limited.
  • Researchers recently identified bacteria in Crete producing metabolites that quickly kill mosquito larvae in lab tests.
  • The compounds might be useful for the development of new biopesticides, though developing the right formulations and delivery method remains a challenge.


Washington, D.C.—Mosquito-borne diseases kill more than 700,000 people every year, according to the World Health Organization, and the mosquitos that spread the disease are difficult to control. Most species have developed resistance to all major classes of synthetic insecticides, many of which pose both environmental and health risks.

Biopesticides, derived from living organisms, may mitigate chemical insecticide resistance and offer an environmentally friendly way forward. This week in Applied and Environmental Microbiology, researchers report that bacterial isolates collected from the Mediterranean island of Crete act as insecticides against Culex pipiens molestus mosquitoes, which can transmit human pathogens such as West Nile Virus and Rift Valley Fever Virus. In lab tests, extracts containing metabolites produced by 3 of the isolates killed 100% of mosquito larvae within 24 hours of exposure. 

Those metabolites might guide the development of biopesticides with minimal ecological side effects, the researchers noted. “They degrade more quickly in the environment and therefore don’t accumulate, and they often don’t kill such a wide range of different insect species as chemical insecticides,” said George Dimopoulos, Ph.D., a molecular entomologist and microbiologist at Johns Hopkins University in Baltimore and at the Institute of Molecular Biology and Biotechnology (IMBB) in Crete. He co-led the new study, conducted in Crete, together with molecular biologist John Vontas, Ph.D., at the IMBB.

Dimopoulos’ research focuses on mosquitoes that transmit human pathogens, and over the past 15 years his group has found microbes that produce metabolites that interfere with the pathogens that cause malaria and dengue, and some bacteria that can kill mosquitoes. More recently, they have been investigating mosquito-killing bacteria in the Mediterranean region as part of the MicroBioPest project, funded by the European Union.

For the new work, they collected 186 samples from 65 locations across Crete. The samples included topsoil, soil from around plant roots, plant tissues, water samples and dead insects. They then exposed C. pipiens molestus larvae to water solutions containing some of the most promising isolates found in the samples. More than 100 of the isolates killed all the mosquito larvae within 7 days, and 37 of those killed the larvae within 3 days. Those 37 isolates represented 20 genera, many of which have not previously been identified as potential biopesticides, said Dimopoulos. 

Further analyses showed that the rapid-acting bacteria killed the larvae not through infection but through the production of compounds like proteins and metabolites. This is promising, Dimopoulos noted, because it suggests that an insecticide based on these bacteria would not depend on the microbes staying alive. The findings have implications not only for controlling mosquitoes but also as safe biopesticides to use for controlling agricultural pests. 

The researchers have now begun studying the chemical nature of those insecticidal molecules more closely and identifying whether they are proteins or metabolites. They’re also mapping out the spectrum of pesticidal activity demonstrated by the bacteria, including screening the isolates against other strains of pathogen-bearing mosquitoes and agricultural pest insects. 

Biopesticides often degrade quickly and require multiple applications, Dimopoulos said, and finding the right way to formulate and deliver the compounds will be a challenge in the future. The new study represents the discovery phase. 

“It’s now entering the basic science phase to understand the molecules’ chemical structures and modes of action, and then we’ll shift to a more applied path, really aiming at prototype product development,” he said. “There is a major push toward developing ecologically friendly insecticides.” 
 

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The American Society for Microbiology is one of the largest professional societies dedicated to the life sciences and is composed of over 37,000 scientists and health practitioners. ASM's mission is to promote and advance the microbial sciences. 

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