Nutrition Diet: What is the 90 minute rule for coffee?

October 1, 2025 •

4 min read

According to sleep experts, drinking coffee immediately upon waking can dull its energizing effects and lead to a mid-afternoon crash. This is the premise behind the increasingly popular theory known as the '90 minute rule for coffee', which suggests that timing your first cup can significantly impact your energy levels and overall well-being.

Quick Summary

The 90-minute coffee rule, championed by neuroscientists like Andrew Huberman, advises delaying your first cup of coffee until 90 to 120 minutes after waking. This strategy aims to align caffeine consumption with the body's natural cortisol and adenosine cycles for more sustained energy and better sleep.

Key Points

Delay for optimal energy: Waiting 90-120 minutes after waking to drink coffee can lead to a more sustained energy boost and prevent the afternoon crash.
Align with cortisol: This timing aligns with your body's natural cortisol peak, ensuring caffeine doesn't interfere with your internal wake-up response.
Minimize adenosine impact: Delaying allows your body to clear residual adenosine naturally, making the caffeine more effective at blocking sleepiness later.
Support long-term energy: The rule can help reduce caffeine dependency, encouraging your body to rely more on its natural wakefulness mechanisms.
Improve sleep quality: By preventing an excessive need for afternoon caffeine, this practice can lead to better quality sleep and a more regular circadian rhythm.
Consider individual factors: The best timing can vary, so listening to your body and experimenting with the rule is key to finding what works best for you.

For many, a cup of coffee is the non-negotiable start to the day, consumed almost immediately after the alarm sounds. However, an emerging school of thought, popularized by neuroscientists and wellness experts, suggests that this habit might be undermining your body’s natural energy systems. The concept, commonly known as the 90-minute rule, proposes a strategic delay in your morning caffeine intake to achieve a more potent and stable energy boost.

The Science Behind the 90-Minute Rule

To understand why this strategy is beneficial, one must first appreciate the intricate interplay of two key biological components: cortisol and adenosine.

The Cortisol Awakening Response

Upon waking, your body experiences a natural surge of cortisol, often called the Cortisol Awakening Response (CAR). This stress hormone helps you feel alert and awake by elevating blood sugar and metabolism. For the average person, this cortisol peak occurs within the first 30 to 60 minutes of rising. Proponents of the 90-minute rule argue that consuming caffeine during this natural high can lead to a few potential issues:

It can blunt the effectiveness of your coffee, essentially stacking an external stimulant on top of your body's own natural alerting system.
It may cause your body to become more reliant on the external caffeine boost, decreasing your natural cortisol production over time and making you feel more groggy on days you don't have coffee right away.
Overstimulation from the combined effect of caffeine and high cortisol can lead to anxiety, jitters, and a sharper energy crash later in the day.

The Role of Adenosine

In addition to cortisol, adenosine is another key player in the sleep-wake cycle. This neurotransmitter promotes sleepiness, and its levels build up in the brain the longer you are awake. During the night, your brain clears out this accumulated adenosine. The 90-minute rule posits that if you drink coffee too early, it begins blocking any remaining adenosine receptors before your body has had a chance to clear it naturally. When the caffeine eventually wears off, there is a subsequent rebound effect where the build-up of adenosine can suddenly bind to its receptors, leading to the dreaded mid-afternoon energy crash. By waiting, you allow your body's natural adenosine levels to drop more effectively, making the caffeine more impactful when it is finally introduced.

Practical Steps to Implement the 90-Minute Rule

Shifting your morning routine doesn't have to be a major overhaul. Here are some actionable steps to start implementing the 90-minute rule:

Start with hydration: Instead of coffee, begin your day with a large glass of water. As caffeine is a diuretic, proper hydration can help mitigate some of its effects.
Get natural light: Exposing your eyes to natural sunlight soon after waking is a powerful way to regulate your circadian rhythm and signal your body to be awake. Go for a short walk or sit by a window.
Move your body: Engage in some light physical activity, like stretching or a brief walk. This can increase your core body temperature and help naturally boost alertness.
Pair with a balanced breakfast: When you do have your coffee, consider drinking it with or after a balanced breakfast. A meal with protein and healthy fats can help stabilize blood sugar levels and provide sustained energy, smoothing out the caffeine’s effects and minimizing jitters.

Immediate Coffee vs. Waiting 90+ Minutes

To better understand the potential impact, consider the two scenarios side-by-side:


Aspect	Immediate Coffee (within 30 mins)	Delayed Coffee (90+ mins after waking)
Energy Level	Quick, intense spike followed by a sharper crash.	Smoother, more sustained boost without the dramatic drop.
Cortisol Levels	Adds a stimulant on top of a natural cortisol peak, potentially increasing jitters and stress response.	Caffeine is introduced as cortisol levels begin to decline, providing a more balanced energy lift.
Adenosine Effect	Blocks residual adenosine from the night, which can cause a bigger 'rebound' crash later.	Allows the body to naturally clear adenosine, making the later caffeine more effective.
Caffeine Tolerance	May increase your body's reliance on caffeine to feel alert, potentially building tolerance over time.	Can reduce dependency, allowing your body to use its natural mechanisms for wakefulness more effectively.
Sleep Quality	Earlier coffee consumption may necessitate later-day caffeine, which can disrupt sleep patterns and reduce deep sleep.	Promotes better circadian rhythm alignment, leading to improved sleep quality.

Conclusion: Finding the Right Rhythm for Your Body

While the science behind the 90-minute rule is compelling, it's worth noting that individual responses to caffeine can vary, and some long-term habitual drinkers may already have adapted. Nevertheless, experimenting with this simple timing adjustment is a low-risk way to potentially boost your daily energy, improve your sleep, and foster a healthier relationship with caffeine. By respecting your body's natural hormonal cycles and circadian rhythm, you can get more out of every cup and avoid the frustrating energy rollercoaster. For more information on caffeine and its effects, consider exploring research from reputable sources, such as the Harvard T.H. Chan School of Public Health, which provides a comprehensive overview of coffee and its health impacts.

What is the 90 minute rule for coffee: A step-by-step guide

Skip the immediate coffee. The moment you wake up, resist the urge to head straight for the coffee maker.
Hydrate first. Drink a large glass of water to rehydrate your body after sleep and support digestion.
Get natural light. Expose yourself to daylight for at least 10-15 minutes, ideally outside, to signal your body to wake up.
Wait 90-120 minutes. This allows your natural cortisol levels to peak and recede, preventing an interference with your body’s internal systems.
Enjoy your coffee. After the waiting period, have your first cup, ideally with or after a nutritious breakfast.
Avoid late consumption. Cut off caffeine intake 6-8 hours before bed to ensure it doesn't disrupt your sleep cycle.

Frequently Asked Questions

The rule is based on two biological concepts: the Cortisol Awakening Response (CAR) and the role of adenosine. The theory suggests that delaying coffee until after the morning cortisol peak, and after lingering adenosine has cleared, makes caffeine more effective at providing a sustained energy boost.

Yes, many people report a reduction in the mid-afternoon energy slump by waiting to consume their first coffee. By allowing your body's natural wakefulness systems to work first, the crash that occurs when caffeine wears off is less severe.

To help with morning grogginess, try incorporating a few habits before your coffee. Prioritize hydration by drinking water, get some natural sunlight exposure, and engage in light physical movement to naturally elevate your energy levels.

The same principles related to cortisol and adenosine apply to other caffeinated beverages and supplements, such as tea, energy drinks, and caffeine pills. Timing their consumption 90-120 minutes after waking is recommended for similar benefits.

To avoid disrupting sleep, it is generally recommended to have a caffeine cut-off time. Most experts suggest stopping caffeine intake at least 6 to 8 hours before your planned bedtime.

Drinking coffee on an empty stomach can increase stomach acid, which may cause digestive issues, anxiety, or jitters in some individuals. Having a balanced breakfast alongside or before your coffee can help mitigate these effects.

The theory is based on well-established principles of chronobiology regarding cortisol and adenosine. However, some experts note that robust, specific research proving the 90-minute delay's direct benefit over immediate coffee is limited. For habitual drinkers, the body may also adapt, reducing the cortisol spike's significance.