TLDR;
This episode of the Huberman Lab podcast focuses on cortisol, a crucial hormone for managing energy, mood, sleep, and immune function. It emphasizes the importance of maintaining a healthy 24-hour cortisol rhythm, with high levels in the morning and low levels at night, to avoid burnout and optimize overall well-being. The discussion covers practical tools and protocols for controlling cortisol levels, including light exposure, hydration, exercise, nutrition, and supplementation.
- Cortisol is essential for energy deployment, not just stress response.
- Maintaining a proper 24-hour cortisol rhythm is vital for health.
- Practical tools like light exposure, hydration, and exercise can regulate cortisol levels.
Cortisol [0:00]
The episode introduces cortisol as a critical hormone that influences mood, sleep, the immune system, and overall well-being. It highlights the importance of understanding and controlling cortisol levels to avoid burnout. The primary focus is on maintaining a healthy 24-hour cortisol rhythm, characterized by high levels in the morning and low levels at night, which is crucial for overall health, wellness, and performance.
Stress, Tool: Daily Cortisol Rhythm [1:29]
Cortisol is a hormone released in response to stress, but it's also involved in other important functions. The key is to have high cortisol levels in the morning and low levels at night. This rhythm is essential for health, wellness, and performance. Addressing issues like morning anxiety and low energy throughout the day can be achieved by correcting the cortisol rhythm.
Cortisol & Directing Energy, Glucose, Adrenals [3:16]
Cortisol is not just a stress hormone but a hormone that directs energy to tissues, especially the brain, by releasing glucose into the bloodstream. It is produced in the adrenal glands, which also produce adrenaline. Cortisol acts on a slower timescale than adrenaline and is essential for various energy-demanding tasks.
Sponsors: Carbon & BetterHelp [6:39]
This section contains advertisements for Carbon, a diet coaching app, and BetterHelp, an online therapy service.
Daily Cortisol Phases & Rhythm, Waking Up & Cortisol [10:14]
Cortisol levels change throughout the day, following a 24-hour rhythm. There are four phases: minimal secretion during the hours before and after sleep, a slight rise in the third to fifth hour of sleep, a rapid increase during the sixth to eighth hour of sleep, and a further increase in the first hour after waking. The first hour after waking is crucial for amplifying cortisol levels and setting the tone for the day.
Cortisol Release & Regulation, Hypothalamic-Pituitary-Adrenal (HPA) Axis [17:55]
Cortisol is produced in the adrenal glands upon instruction from the brain. The process begins in the hypothalamus, which releases corticotropin-releasing hormone (CRH). CRH stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH), which then travels to the adrenal glands, prompting the synthesis and release of cortisol. As cortisol levels rise, they trigger a negative feedback loop, shutting down further CRH release to maintain balance.
Rapid & Delayed Stress Response, HPA Axis [24:57]
The hypothalamic-pituitary-adrenal (HPA) axis is crucial for cortisol synthesis and the 24-hour rhythm. Stress activates the HPA axis, leading to a rapid response via adrenaline and a slower response via cortisol. Adrenaline causes immediate changes, while cortisol's effects take about 10 minutes to manifest and last longer.
Bright Light & Cortisol Release, Tool: Increase Morning Cortisol & Sunlight [28:42]
The suprachiasmatic nucleus (SCN), the brain's central circadian pacemaker, also controls cortisol release. A parallel pathway from the SCN to the adrenal glands, activated by bright light, allows for increased cortisol release in the morning. Getting bright light, ideally sunlight, in the eyes within the first hour of waking boosts cortisol levels, improving mood, focus, and alertness.
Sponsors: AG1 & David [36:58]
This section contains advertisements for AG1, a vitamin mineral probiotic drink, and David, a protein bar.
Viewing Bright Light & Mood, Depression, Seasonal Affective Disorder (SAD) [39:48]
Viewing morning sunlight or bright light can increase cortisol levels by up to 50%, which is clinically significant for improving mood and offsetting seasonal depression (SAD). This practice is especially important in areas with limited sunlight during winter.
Increase Morning Cortisol, Tools: Hydration, Delaying Caffeine Intake [41:44]
Besides bright light, hydration also boosts morning cortisol levels. Drinking 16 to 32 ounces of water upon waking increases alertness. For habitual caffeine users, delaying caffeine intake by 60 to 90 minutes can prolong cortisol's effectiveness and prevent afternoon crashes.
Exercise, Entrainment Cues & Cortisol Rhythm, Tool: Boost Energy & Exercise Schedule [49:30]
Exercise increases cortisol, but the effect is less pronounced with familiar routines. Regular exercise at the same time each day acts as an entrainment cue, reinforcing the cortisol rhythm and boosting energy levels. Exercising within the same two to three-hour window daily can lead to an anticipatory rise in cortisol, providing more energy for workouts.
Does Deliberate Cold Exposure Increase Cortisol?, Energy & Mood [57:52]
Deliberate cold exposure, like cold showers, increases epinephrine and dopamine, boosting mood and energy. However, it only increases cortisol significantly if done occasionally (no more than twice per week). Regular cold exposure does not chronically elevate cortisol but still provides benefits from increased dopamine and epinephrine.
Sponsor: LMNT [1:01:19]
This section contains an advertisement for LMNT, an electrolyte drink.
Increase Morning Cortisol & Nutrition, Grapefruit, Black Licorice [1:02:51]
Grapefruit extends the life of cortisol by inhibiting enzymes that break it down, increasing cortisol's duration by 25-50%. Black licorice contains glycyrrhizin, which potently increases cortisol levels by inhibiting the enzyme that converts cortisol to cortisone. However, those with hypertension or who are pregnant should avoid black licorice.
Afternoon & Evening Cortisol Rhythms, Sunlight, Screens [1:11:34]
In the afternoon, bright light does not increase cortisol but can improve mood. In the evening, artificial light, especially from screens, can significantly increase cortisol due to heightened sensitivity.
Lower Evening Cortisol, Tools: Dim Lights, Light Color [1:14:30]
To lower evening cortisol, dim indoor lights, turn off overhead lights, and use table or floor lamps. Avoid short-wavelength light by using red light bulbs or screen filters. Glasses that block short-wavelength light can also be helpful.
Lower Evening Cortisol, Tools: Caffeine Timing; Stress Response & Exhales; Starchy Carbohydrates [1:20:54]
Avoid caffeine in the late afternoon to prevent prolonged cortisol elevation. Manage stress with exhale-emphasized breathing, such as the physiological sigh. Consuming starchy carbohydrates with dinner can also help keep cortisol levels low by increasing blood glucose.
Low-Carb Diets & Cortisol, Metabolic Syndrome [1:30:42]
Low-carbohydrate diets can initially increase cortisol levels for about three weeks, but levels normalize afterward. If sleep is good on a low-carb diet, there's no need to worry. However, those transitioning to a low-carb diet may experience increased stress. In individuals with metabolic syndrome, cortisol levels may increase due to insulin insensitivity.
Evening Exercise & Cortisol, Tool: Spike Your Morning Cortisol [1:35:30]
Exercising late in the day can spike cortisol levels, disrupting sleep. If evening workouts are necessary, consume protein and starchy carbohydrates afterward, practice long exhale breathing, and avoid bright light to lower cortisol. Spiking cortisol at night can blunt the next morning's cortisol response, so take extra effort to boost morning cortisol if this occurs.
Supplements to Reduce Cortisol, Ashwagandha, Apigenin, Magnesium [1:44:32]
Supplements like ashwagandha (300-900 mg) and apigenin can help reduce cortisol levels in the evening. Ashwagandha can reduce cortisol by 11-29%, while apigenin, found in chamomile tea, has a milder effect. Magnesium threonate may also indirectly help suppress cortisol.
Burnout, Cushing's & Addison's, 2 Burnout Patterns [1:50:57]
Burnout is a real condition, but it's not due to adrenal failure. It's distinct from medical conditions like Cushing's (hyper-elevated cortisol) and Addison's (adrenal insufficiency). There are two main patterns of burnout: waking up stressed and exhausted later, or waking up exhausted and stressed at night.
Early-Phase Burnout, Tools: NSDR/Yoga Nidra, Boost Morning Cortisol, Caffeine [1:55:23]
For early-phase burnout (stressed in the morning, exhausted later), use non-sleep deep rest (NSDR) or yoga nidra to reduce cortisol levels upon waking. Hydrate, get bright light to shift the cortisol peak, and delay caffeine intake to flatten the cortisol curve.
Late-Phase Burnout, Tools: Reduce Evening Cortisol [2:01:35]
For late-phase burnout (stressed at night, exhausted in the morning), focus on reducing evening cortisol levels. Avoid bright light, caffeine, and stress. Practice long exhale breathing and consider a relaxing walk at sunset.
Age, Male vs Females, Lifespan, Cancer; Menopause; Brain Health [2:08:02]
Cortisol secretion patterns are similar in males and females until age 40, after which the morning cortisol peak tends to decrease with age. In women transitioning to menopause, there is a characteristic flattening of the cortisol rhythm. Maintaining a high morning cortisol peak and managing stress can improve survivability in chronic illnesses like cancer.
Zero-Cost Support, YouTube, Spotify & Apple Follow & Reviews, Sponsors, YouTube Feedback, Protocols Book, Social Media, Neural Network Newsletter [2:13:41]
The episode concludes with ways to support the podcast, including subscribing on YouTube, following on Spotify and Apple, leaving reviews, checking out sponsors, and providing feedback. It also mentions the upcoming book "Protocols" and encourages listeners to follow Andrew Huberman on social media and subscribe to the Neural Network Newsletter.
