Sleep strengthens muscle and bone by boosting growth hormone levels. UC Berkeley researchers discover how

From news.berkeley.edu

Growth hormone released during sleep is critical not only for childhood growth but also for adult metabolism. A new study reveals the complex brain circuits involved, offering fresh insights into health and fitness 

As every bodybuilder knows, a deep, restful sleep boosts levels of growth hormone to build strong muscle and bone and burn fat. And as every teenager should know, they won’t reach their full height potential without adequate growth hormone from a full night’s sleep.

But why lack of sleep — in particular the early, deep phase called non-REM sleep — lowers levels of growth hormone has been a mystery.

In a study published in the current issue of the journal Cell, researchers from University of California, Berkeley, dissect the brain circuits in mice that control growth hormone release during sleep and report a novel feedback mechanism in the brain that keeps growth hormone levels finely balanced.

The findings provide a map for understanding how sleep and hormone regulation interact. The new feedback mechanism could open avenues for treating people with sleep disorders tied to metabolic conditions like diabetes, as well as degenerative diseases like Parkinson’s and Alzheimer’s.

“People know that growth hormone release is tightly related to sleep, but only through drawing blood and checking growth hormone levels during sleep,” said study first author Xinlu Ding, a postdoctoral fellow in UC Berkeley’s Department of Neuroscience and the Helen Wills Neuroscience Institute. “We’re actually directly recording neural activity in mice to see what’s going on. We are providing a basic circuit to work on in the future to develop different treatments.”

Because growth hormone regulates glucose and fat metabolism, insufficient sleep can also worsen risks for obesity, diabetes and cardiovascular disease.

The sleep-wake cycle

The neurons that orchestrate growth hormone release during the sleep-wake cycle — growth hormone releasing hormone (GHRH) neurons and two types of somatostatin neurons — are buried deep in the hypothalamus, an ancient brain hub conserved in all mammals. Once released, growth hormone increases the activity of neurons in the locus coeruleus, an area in the brainstem involved in arousal, attention, cognition and novelty seeking. Dysregulation of locus coeruleus neurons is implicated in numerous psychiatric and neurological disorders.

Researchers recorded brain activity in sleeping and awake mice while stimulating neurons in the brain’s hypothalamus.

Yang Dan lab/UC Berkeley

“Understanding the neural circuit for growth hormone release could eventually point toward new hormonal therapies to improve sleep quality or restore normal growth hormone balance,” said Daniel Silverman, a UC Berkeley postdoctoral fellow and study co-author. “There are some experimental gene therapies where you target a specific cell type. This circuit could be a novel handle to try to dial back the excitability of the locus coeruleus, which hasn’t been talked about before.”

The researchers, working in the lab of Yang Dan, a professor of neuroscience and of molecular and cell biology, explored the neuroendocrine circuit by inserting electrodes in the brains of mice and measuring changes in activity after stimulating neurons in the hypothalamus with light. Mice sleep for short periods — several minutes at a time — throughout the day and night, providing many opportunities to study growth hormone changes during sleep-wake cycles.

Using state-of-the-art circuit tracing, the team found that the two small-peptide hormones that control the release of growth hormone in the brain — GHRH, which promotes release, and somatostatin, which inhibits release — operate differently during REM and non-REM sleep. Somatostatin and GHRH surge during REM sleep to boost growth hormone, but somatostatin decreases and GHRH increases only moderately during non-REM sleep to boost growth hormone.

Released growth hormone regulates locus coeruleus activity, as a feedback mechanism to help create a homeostatic yin-yang effect. During sleep, growth hormone slowly accumulates to stimulate the locus coeruleus and promote wakefulness, the new study found. But when the locus coeruleus becomes overexcited, it paradoxically promotes sleepiness, as Silverman showed in a study published earlier this year.

“This suggests that sleep and growth hormone form a tightly balanced system: Too little sleep reduces growth hormone release, and too much growth hormone can in turn push the brain toward wakefulness,” Silverman said. “Sleep drives growth hormone release, and growth hormone feeds back to regulate wakefulness, and this balance is essential for growth, repair and metabolic health.”

Because growth hormone acts in part through the locus coeruleus, which governs overall brain arousal during wakefulness, a proper balance could have a broader impact on attention and thinking.

“Growth hormone not only helps you build your muscle and bones and reduce your fat tissue, but may also have cognitive benefits, promoting your overall arousal level when you wake up,” Ding said.

The work was funded by the Howard Hughes Medical Institute (HHMI), which until this year supported Dan as an HHMI investigator, and the Pivotal Life Sciences Chancellor’s Chair fund. Dan is the Pivotal Life Sciences Chancellor’s Chair in Neuroscience. Other co-authors of the paper are Peng Zhong, Bing Li, Chenyan Ma, Lihui Lu, Grace Jiang, Zhe Zhang, Xiaolin Huang, Xun Tu and Zhiyu Melissa Tian of UC Berkeley; and Fuu-Jiun Hwang and Jun Ding of Stanford University.

https://news.berkeley.edu/2025/09/08/sleep-strengthens-muscle-and-bone-by-boosting-growth-hormone-levels-uc-berkeley-researchers-discover-how/

"I Banished My Insomnia With One Quick Sleep Hack"

From cnet.com/health 

By Adam Benjamin

Forget counting sheep. This quick hack can help you get to sleep without tossing and turning

Everyone knows that getting a good night's sleep is crucial to functioning the next day, but that doesn't mean going to sleep comes easily. Insomnia might start when you've had a stressful day, or when you have a big event coming up, and before you know it, each night getting quality rest becomes a struggle.

Millions of people struggle to fall asleep, often lying awake for hours. Calming sounds like rain or thunderstorms can definitely help, but they're not your only option. There's a simple trick that might help you drift off faster -- and it only takes five minutes to try.

For me, back in high school, falling asleep was nearly impossible. I knew what was ahead each night: lying awake for hours and rarely getting more than four hours of sleep. It's a torturous, vicious cycle, and I wasn't alone. Insomnia is estimated to affect almost half the population. While I never sought out an insomnia diagnosis, the struggle plagued me nightly.

Fortunately, over time, I managed to regain control of my sleep schedule, and now, on most nights, I fall asleep within 15 minutes. Many things in my life have changed since then, but one particular change had a shockingly positive effect on my ability to fall asleep: I started writing to-do lists every night before bed. 

Creating a to-do list and clearing my mind works wonders

When I started making nightly to-do lists, I didn't have any idea it was going to help me sleep -- I just wanted a way to better track my priorities and productivity from day to day. So every night before bed, I would write down three things I wanted to do the next day. I would also note one good thing that happened during the day, no matter how small. The whole process takes me five minutes at most.

I later learned there may be a connection between clearing our minds and falling asleep. According to a study by researchers from Baylor and Emory universities, making a list of upcoming tasks can help you fall asleep faster. 

The Baylor and Emory study looked at people who journaled before bed about completed tasks and activities and compared them with a second group who made a to-do list of things they needed to do over the next day or two before bed. The study showed that writing to-do lists helped people fall asleep significantly faster than writing about completed activities. 

The researchers speculate that writing out to-do lists eases the stress and anxiety about upcoming events that tend to keep people up at night. In short, writing things down can help offload worries from your brain onto the page. 

Expert advice on ways to get better sleep

Sleep allows your brain to rest and reset, allowing you to function properly tomorrow.   

James Martin/CNET

If you're curious about other ways to get a good night's sleep, I spoke with Dr. Saroja Sripathi, sleep medicine chair for Kaiser Permanente Northern California, for other ideas. She said good sleep is a matter of three factors: the quality of sleep you get, how long you sleep and the timing of your sleep. The best way to maximize all three is to focus on what sleep experts call "sleep hygiene," the behaviours that help you sleep better.

If you have trouble falling asleep at night, Sripathi has research-backed recommendations for improving your sleep quality:

• Stay away from electronic screens for at least half an hour before bed.
• Avoid caffeine and alcohol before bed (alcohol might help you fall asleep, but it's likely to decrease the quality of your sleep).
• Create a consistent routine that helps signal to your body that it's time for sleep.
• Go to bed at the same time every night and wake up at the same time each morning.
• Save your bed for sleep and sex -- keep your reading, snacking and watching to other parts of your home.
• If you need to wind down at the end of the night, listen to podcasts or guided meditation instead of scrolling through social media or other sites.

If you've tried these techniques and are still having issues sleeping, it might be time to seek professional help. Your doctor can work with you to diagnose and treat any potential issues.

Factors that affect your quality of sleep 

Getting good and sufficient sleep can be a challenge. For most of us, there's usually more to do than we can fit in a day, and it's tempting to cut time out of the 7-plus hours that experts recommend adults sleep every night. But how important is sleep, really?

Sripathi told me that sleep affects more than just how rested you feel the next day. "Our overall physical and emotional well-being is affected by sleep," she said, so it's important to prioritize sleep.

Hearing about the benefits of good sleep made me appreciate just how much influence sleep has on our lives. Here are a few things Sripathi said sleep affects:

• Our mood: Good sleep improves mood, and people experiencing issues like depression and anxiety typically complain about sleep problems. 
• Our judgement: Getting better-quality sleep charges our minds and can help us think more clearly so we can make better decisions. We have better judgment and can work faster.
• Our memory: Calling all college students -- pulling all-nighters while studying is ultimately counterproductive because our brains need to sleep to consolidate what we've learned during the day.
• Our immune system: Better sleep can help us stay healthy because our bodies scan for illness while we're sleeping. Sleep can even help with heart health, an important factor in avoiding heart disease.
• Our bodies: For kids, sleep helps with body development. That's why children need more sleep than adults -- as much as 18 hours per day for newborns.

By creating a good sleep environment and building healthy sleep habits, you have a good chance of helping to program your body to sleep better at night. For me, making a to-do list for the next day was a helpful part of that programming, and I've been snoozing much more easily ever since.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.

https://www.cnet.com/health/sleep/i-banished-my-insomnia-with-one-quick-sleep-hack/