A No No for 9-9-6 and Sleep

Questioning the 9-9-6 Schedule

Recently we were made aware of a new work schedule trend: the adoption of the "996" work schedule (working from 9 a.m. to 9 p.m., six days a week) by segments of the Bay Area tech community. While it isn't a surprise that many industries have long working hours and high productivity demands, this trend concerns us because it represents a challenge to established principles of health and wellness, particularly concerning sleep. This relentless schedule appears to systematically minimize the hours available for necessary rest. Given the clear biological imperative for sufficient sleep to maintain cognitive function, regulate mood, and mitigate the long-term risk of neurodegenerative disease and other chronic health issues, we are not a fan of this emerging example of work culture. Sleep as you know is extremely important!

Why Sleep is Non-Negotiable
Sleep is far more than just "downtime." It is a critical, complex biological process that is essential for both physical and mental health. During sleep, your body and mind engage in vital restoration and maintenance.
Here is a brief look at what happens when you sleep:

• Memory Consolidation: Sleep helps solidify memories and learning.
• Physical Restoration: Your body repairs muscle tissue, synthesizes hormones, and eliminates toxins.
• Emotional Regulation: Adequate sleep is crucial for managing mood, stress, and overall mental health.
• Sleep affects almost every type of tissue and system in the body—from the brain, heart, and lungs to metabolism, immune function, mood, and disease resistance.

Ignoring your need for sleep has consequences, including decreased cognitive function, weakened immunity, and an increased risk of chronic diseases.
Recent research published in the Journal of the American Heart Association and highlighted by Medscape reveals that "night owls"—individuals with a natural preference for late-night activity—face a 16% higher risk of experiencing major cardiovascular events like heart attack and stroke compared to those with intermediate sleep patterns. The study, which followed over 300,000 adults for nearly 14 years, found that this increased risk is largely driven by modifiable lifestyle factors, such as poorer diet quality, higher rates of nicotine use, and insufficient sleep. The association was particularly pronounced in women, who showed significantly lower scores on the American Heart Association’s "Life’s Essential 8" cardiovascular health metrics. 

How much sleep do you need
Human sleep needs dramatically decrease as we age, starting from a high of 18 hours for infants down to just 5 hours for older adults. While children and teenagers still require a solid 10 hours to support their development, adults typically level off at around 9 hours of rest. This trend highlights how our biological demand for sleep shifts from a state of rapid growth to one of maintenance and maturity.










​Credit: NIH 




Understanding Your Brain's Cleaning System: The Glymphatic System and Sleep
Just as your body has a lymphatic system to remove waste from tissues, your brain has its own specialized network that clears out harmful metabolic waste products that accumulate throughout the day called the glymphatic system. The glymphatic system works through a series of fluid-filled channels that surround your brain's blood vessels. Cerebrospinal fluid (the clear fluid that cushions your brain and spinal cord) flows through these channels, washing away waste products and toxic proteins that your brain cells produce during normal activity. This waste includes proteins like amyloid-beta and tau, which are associated with Alzheimer's disease when they accumulate.

How Does Sleep Activate This System?
The glymphatic system is most active during deep sleep, particularly during the stage called non-REM (NREM) sleep or slow-wave sleep. During deep sleep, several important changes occur in your brain. The spaces between brain cells expand by up to 60%, allowing more fluid to flow through and flush out waste products more efficiently. Blood vessels in the brain undergo rhythmic pulsations approximately every 50 seconds during deep sleep. These pulsations act like a pump, propelling cerebrospinal fluid through the brain's cleaning channels. Research has shown that the clearance of harmful metabolites mostly occurs during sleep and is essentially inactive during waking hours.  

What Happens When You Don't Get Enough Sleep?
Sleep deprivation therefore significantly impairs your brain's ability to clear waste. Studies using PET scans have shown that even a single night of poor sleep leads to accumulation of amyloid-beta protein in the healthy brain. Over time, chronic sleep problems may contribute to:
- Increased risk of neurodegenerative diseases like Alzheimer's and Parkinson's disease
- Cognitive decline and memory problems
- Accumulation of toxic proteins in brain tissue

Mastering Sleep Hygiene
Sleep hygiene refers to a set of behavioral and environmental practices that promote consistent, high-quality sleep. While sleep hygiene alone may not resolve chronic insomnia (which typically requires cognitive behavioral therapy), these evidence-based recommendations form the foundation of healthy sleep habits.
Sleep-Wake Schedule

• Maintain a consistent wake time every morning, including weekends. This helps regulate your body's internal clock and strengthens your natural sleep drive.
•  Go to bed only when sleepy, not based on the clock. If you cannot fall asleep within 20 minutes, get out of bed and return only when sleepy again.
• Aim for 7-9 hours of sleep per night

Bedroom Environment

• Keep your bedroom temperature between 24-26°C (75-79°F), as higher temperatures reduce deep sleep and overall sleep efficiency.
• Minimize noise exposure, as it significantly reduces sleep efficiency, particularly in women.
• White/Pink noise machines/sounds which are commonly used has actually been associated with worse sleep than ear plugs- so put those in instead
•  Use blackout curtains or eye masks to eliminate light exposure during sleep hours

Light Exposure

• Maximize bright light exposure during daytime hours, especially in the morning, to strengthen circadian rhythms.
•  Reduce bright light exposure in the evening, particularly blue-enriched light from screens, for at least 1-2 hours before bedtime.
•  Use dim, warm-toned lighting in the evening to support natural melatonin production.

Caffeine Management

• Avoid caffeine consumption at least 8-9 hours before your intended bedtime.
• A standard cup of coffee (107 mg caffeine) consumed later than this window reduces total sleep time by approximately 45 minutes and decreases sleep efficiency by 7%.
•  Higher doses, such as pre-workout supplements, should be avoided for at least 13 hours before bedtime.
•  Caffeine particularly reduces deep sleep (slow-wave sleep) and increases the time needed to fall asleep.

Alcohol and Nicotine

• Avoid alcohol within 4 hours of bedtime. While alcohol may initially promote drowsiness, it significantly fragments sleep, reduces sleep efficiency, and suppresses deep sleep throughout the night.
•  Avoid nicotine within 4 hours of bedtime, as it reduces sleep efficiency by approximately 1.7% and increases nighttime awakenings

Daytime Behaviors

• Limit or eliminate daytime napping, as naps reduce nighttime sleep drive.
• If napping is necessary, keep it brief (20-30 minutes) and before 3 PM. Engage in regular physical activity, but avoid vigorous exercise within 2-3 hours of bedtime.
•  Avoid large meals close to bedtime, though a light snack may be appropriate if hungry.

Bedroom Use

• Reserve your bed and bedroom exclusively for sleep and intimacy—no reading, watching television, working, or using electronic devices in bed.
•  This strengthens the mental association between your bedroom and sleep.

When to Seek Additional Help

• If sleep difficulties persist despite consistent adherence to these practices for 2-4 weeks, consult your healthcare provider. Chronic insomnia typically requires cognitive behavioral therapy, which is more effective than sleep hygiene education alone and provides superior long-term outcomes compared to medication

Sleep Trackers like Oura and WHOOP
As digital health technologies and consumer wearables become increasingly integrated into our daily routines, sleep trackers offer a highly accessible way to monitor general health and wellness. However, it is essential to understand both their capabilities and their limitations when evaluating the data they produce. While these devices are excellent for identifying broad lifestyle patterns, their output does not always align with your subjective symptoms; you may wake up feeling completely refreshed despite your wearable recording a night of highly fragmented rest, or vice versa. Additionally, the accuracy of these algorithms is not universal. A recent study evaluating these devices demonstrated that commercial sleep trackers are significantly less accurate in older adults, frequently underestimating total sleep time and mischaracterizing deep sleep stages compared to younger populations. Because of these physiological variables and algorithmic blind spots, commercial trackers cannot currently replace gold-standard diagnostic sleep studies, such as in-lab polysomnography. Ultimately, while they cannot be used to officially diagnose clinical sleep disorders, they remain valuable supplementary tools for personal wellness tracking when viewed and interpreted in the proper context 

If you have more questions and especially if you suspect you may have a sleep disorder, consult a healthcare professional. 
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​*The information provided on this blog does not constitute medical advice; always consult with a qualified healthcare provider regarding any health or medical conditions
References:
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