Medical Bulletin 15/November/2025 - Video

Here are the top medical news for the day:

Weight training outperforms running for weight loss, diabetes control, Study Finds

Scientists have found some great news for those who dislike aerobic exercises like running: weightlifting might actually be better at burning fat and improving blood sugar control. A new study conducted on mice by researchers at Virginia Tech, published in the Journal of Sport and Health Science, compared the effects of running and weightlifting on obesity and diabetes-related health issues.

Weight training offers unique benefits that make it especially effective for improving body composition and metabolism. Unlike aerobic exercises like running, which burn more calories during the activity, weightlifting builds lean muscle mass that burns more calories even when at rest. This increased muscle mass raises the resting metabolic rate, helping the body burn fat long after the workout is over. Weight training also improves insulin sensitivity, aiding blood sugar control and reducing the risk of metabolic diseases. Additionally, it strengthens bones and joints, reducing injury risk. Combining weightlifting with cardio provides the best overall health benefits.

The study involved three groups of mice fed a high-fat diet to induce obesity. One group performed resistance training by lifting weighted lids to access food, mimicking weightlifting. The second group ran voluntarily on wheels, simulating endurance exercise. The third group did not exercise. Over eight weeks, researchers monitored the mice's weight, fat levels, insulin sensitivity, and muscle function.

Results showed that both running and weightlifting helped reduce abdominal and under-the-skin fat and improved blood sugar regulation through better insulin signaling in muscles. However, weightlifting outperformed running by more effectively lowering fat and improving glucose tolerance, which is crucial for preventing diabetes and obesity. Weightlifting also enhanced muscle strength and metabolism, supporting long-term fat loss.

Lead researcher Zhen Yan explained that while aerobic exercise is beneficial for the heart and calorie burning, resistance exercise builds muscle mass, which burns more calories even at rest and helps regulate blood sugar better. He emphasized that combining both endurance and resistance training provides the greatest health benefits.

The study's findings underline the importance of including muscle-strengthening activities like weightlifting, resistance bands, or body-weight exercises such as pushups and lunges in fitness routines. While cardio builds endurance, weight training may be more effective in targeting obesity and improving metabolic health.

REFERENCE: Robert J. Shute, Ryan N. Montalvo, Wenqing Shen, Yuntian Guan, Qing Yu, Mei Zhang, Zhen Yan; Weightlifting outperforms voluntary wheel running for improving adiposity and insulin sensitivity in obese mice; Journal of Sport and Health Science; 2025; https://doi.org/10.1016/j.jshs.2025.101100.

Vitamin D3 found to cut second heart attack risk by half: Study

Heart attack survivors face a high risk of recurrence, but a breakthrough study from Intermountain Health offers hope — personalized vitamin D3 treatment can halve that risk. In a large randomized clinical trial called TARGET-D, scientists used a precision approach, adjusting vitamin D3 dosages to reach and maintain optimal blood levels, transforming a simple nutrient into a powerful lifesaver.

While previous studies on Vitamin D3 and heart health have suggested mixed results, it is essential to note that this is a preliminary finding presented at The American Heart Association Scientific Sessions (2025), but it has yet to be published in a peer-reviewed journal.

Low vitamin D has long been linked to poor heart health, yet past trials using fixed supplementation doses failed to reduce heart attack rates. The Intermountain researchers took a different tack: instead of one-size-fits-all dosing, they closely monitored blood vitamin D levels and tailored supplements to raise levels above 40 nanograms per milliliter, a target considered ideal. This “target-to-treat” strategy ensured each patient received the right amount to impact their heart health.

The TARGET-D trial enrolled 630 heart attack survivors within one month of their event and followed them through early 2025. Patients were randomly assigned either to standard care or to active vitamin D3 management involving dose adjustments and frequent monitoring.

Initially, 85% of participants had levels below 40 ng/mL, with many requiring high doses of 5,000 IU—far above typical recommendations. Blood levels were checked every three months in those not yet at target and yearly once the optimal range was achieved.

Although the overall incidence of major cardiac events (including strokes and heart failure) did not differ significantly, targeted vitamin D3 treatment dramatically cut the chance of a second heart attack by 50%. Importantly, no adverse effects were observed with higher doses, underscoring safety along with effectiveness.

Researchers plan larger trials to confirm and expand on these promising results, aiming to solidify vitamin D3’s role in cardiac care. This study marks a pivotal shift from generic supplementation toward personalized, monitored micronutrient therapy that could save lives after a heart attack.

REFERENCE: Intermountain Healthcare. "Vitamin D3 breakthrough halves risk of second heart attack." ScienceDaily. ScienceDaily, 10 November 2025. .

Study uncovers how mental fatigue causes the brain to zone out

A new study reveals what happens in the brain when sleep deprivation causes attention lapses — the brain flushes out cerebrospinal fluid (CSF) in large pulses, a mechanism normally seen during sleep, but intruding into wakefulness with a cost to focus. This breakthrough research, published in Nature Neuroscience, provides fresh insights into why we struggle to pay attention after a sleepless night.

Sleep deprivation is notorious for impairing mental performance, yet the brain mechanisms behind this have been unclear. The study involved 26 healthy adults aged 19 to 40 participating in well-rested and totally sleep-deprived conditions about 10 days apart.

Using simultaneous EEG caps to measure brain waves, functional MRI scans to track blood and CSF flow, and eye-tracking to capture pupil size, researchers monitored brain and body activity. Participants performed attention tasks responding to visual and auditory cues, while baseline rest data was also collected.

Findings showed that attention failures during sleep deprivation occur alongside large pulses of CSF flowing out of the brain, followed by a reverse flood when attention recovers. These CSF pulses closely mimicked patterns seen in non-REM sleep stages N1 and N2, accompanied by slow brain waves and changes in blood flow and pupil size.

The flushing out of CSF coincided exactly with moments participants “zoned out,” revealing a synchronized brain-body response. This suggests the sleep-deprived brain transiently slips into a sleep-like state without fully sleeping.

Lead researcher Laura Lewis explained that this coupling of CSF flow, brain waves, blood circulation, and pupil changes was unexpected but shows a tightly integrated system.

The study highlights the role of the autonomic nervous system in orchestrating these dynamics. While the exact functional implications remain to be explored, this work opens new avenues for understanding cognitive impairment from sleep loss and identifying potential treatments for sleep disorders.

These results underscore the biological consequences of even one night without sleep, revealing a brain desperately attempting to perform restorative “cleaning” at the cost of alertness and attention.

REFERENCE: Yang, Z., Williams, S.D., Beldzik, E. et al. Attentional failures after sleep deprivation are locked to joint neurovascular, pupil and cerebrospinal fluid flow dynamics. Nat Neurosci (2025). https://doi.org/10.1038/s41593-025-02098-8