TLDR;
This episode of the Huberman Lab podcast focuses on cortisol, a crucial hormone for managing energy, stress, and overall well-being. It highlights the importance of maintaining a healthy cortisol rhythm, with high levels in the morning and low levels in the evening, to avoid burnout and optimise health. The discussion covers practical tools and science-backed strategies to control cortisol levels throughout the day, addressing issues like burnout, sleep disruption, and mood disorders.
- Understanding cortisol's role in energy deployment, not just stress.
- Importance of light exposure, hydration, and exercise for regulating cortisol.
- Practical tools for managing cortisol levels to avoid burnout and optimise health.
Cortisol [0:00]
Cortisol is a vital hormone that influences mood, sleep, the immune system, and overall well-being. It's often associated with stress, but it primarily functions to deploy and direct energy to tissues, especially the brain. Maintaining a proper cortisol rhythm is essential, with high levels in the morning and low levels at night, to reinforce health, wellness, and performance.
Stress, Tool: Daily Cortisol Rhythm [1:29]
Cortisol is released in response to stress, but it's also crucial for various other functions. The key is to manage cortisol levels effectively, ensuring they are high in the morning and low before sleep. This rhythm is vital for overall health, and correcting it can resolve issues like burnout, lack of morning energy, and insomnia.
Cortisol & Directing Energy, Glucose, Adrenals [3:16]
Cortisol directs energy to tissues that need it most by releasing glucose into the bloodstream. It's produced in the adrenal glands and acts more slowly than adrenaline. Cortisol crosses the blood-brain barrier, affecting brain regions like the hippocampus, which is important for memory and understanding chronic stress.
Sponsors: Carbon & BetterHelp [6:39]
This section features sponsors, Carbon, a diet coaching app, and BetterHelp, an online therapy service.
Daily Cortisol Phases & Rhythm, Waking Up & Cortisol [10:14]
Cortisol levels vary throughout the day in four phases: minimal secretion during the four hours before and two hours 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. This 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 production is regulated by the hypothalamic-pituitary-adrenal (HPA) axis. Neurons in the hypothalamus release corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to release adrenocorticotropic hormone (ACTH). ACTH then stimulates the adrenal glands to produce cortisol. Cortisol levels are self-regulated through a negative feedback loop, where high cortisol levels inhibit further CRH release.
Rapid & Delayed Stress Response, HPA Axis [24:57]
The HPA axis is activated by stress, leading to both rapid and delayed responses. The rapid response involves adrenaline and noradrenaline release, while the delayed response involves cortisol synthesis and glucose release, taking about 10 minutes. This explains why stress can persist even after the stressor is resolved.
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. Bright light exposure, especially in the morning, activates the SCN, boosting cortisol levels through a parallel pathway. Getting sunlight in your eyes within the first hour of waking is recommended to increase morning cortisol, energy, and mood.
Sponsors: AG1 & David [36:58]
This section features sponsors, AG1, a vitamin mineral probiotic drink, and David, a protein bar.
Viewing Bright Light & Mood, Depression, Seasonal Affective Disorder (SAD) [39:48]
Morning sunlight exposure significantly increases cortisol levels, improving energy, mood, and focus. This practice is clinically significant and can offset seasonal affective disorder (SAD) and mild depression.
Increase Morning Cortisol, Tools: Hydration, Delaying Caffeine Intake [41:44]
Besides bright light, hydration is crucial for increasing morning cortisol and alertness. Drinking 16 to 32 ounces of water upon waking can modestly increase cortisol release. For habitual caffeine users, delaying caffeine intake by 60 to 90 minutes can extend 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.
Does Deliberate Cold Exposure Increase Cortisol?, Energy & Mood [57:52]
Deliberate cold exposure can increase cortisol, but this effect diminishes with regular practice. Occasional cold exposure can boost catecholamines, dopamine, epinephrine, and norepinephrine, improving mood and energy.
Sponsor: LMNT [1:01:19]
This section features sponsor, LMNT, an electrolyte drink.
Increase Morning Cortisol & Nutrition, Grapefruit, Black Licorice [1:02:51]
Grapefruit extends cortisol's life by inhibiting enzymes that break it down, increasing its duration by 25 to 50%. Black licorice contains glycyrrhizin, which potently increases cortisol levels by inhibiting its conversion 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 has a calming effect due to the circadian dead zone. However, in the evening, bright light, especially from screens, can cause significant cortisol increases.
Lower Evening Cortisol, Tools: Dim Lights, Light Color [1:14:30]
To lower evening cortisol, dim indoor lights, turn off overhead lights, and use red or amber-coloured lights. Dimming screens and using blue-light-blocking glasses can also help.
Lower Evening Cortisol, Tools: Caffeine Timing; Stress Response & Exhales; Starchy Carbohydrates [1:20:54]
Avoid caffeine in the late afternoon and manage stress with exhale-emphasised breathing techniques like the physiological sigh. Consuming starchy carbohydrates in the evening can also help lower cortisol levels.
Low-Carb Diets & Cortisol, Metabolic Syndrome [1:30:42]
Low-carbohydrate diets can initially increase cortisol levels, but they typically normalise after three weeks. If sleep is good on a low-carb diet, there's no need to worry. However, those with metabolic syndrome may experience elevated cortisol due to insulin insensitivity.
Evening Exercise & Cortisol, Tool: Spike Your Morning Cortisol [1:35:30]
Exercising late in the day can spike cortisol levels, so it's important to take steps to bring them down afterwards, such as eating starchy carbohydrates, doing long exhale breathing, and avoiding bright light.
Supplements to Reduce Cortisol, Ashwagandha, Apigenin, Magnesium [1:44:32]
Supplements like ashwagandha and apigenin can help reduce cortisol levels in the evening. Ashwagandha can reduce cortisol by 11% to 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, distinct from medical conditions like Cushing's and Addison's. There are two main patterns of burnout: waking up stressed and exhausted in the afternoon, 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, characterised by morning stress and afternoon exhaustion, non-sleep deep rest (NSDR) or yoga nidra can help reduce cortisol levels. Hydrate and get bright light in your eyes upon waking, and delay caffeine intake.
Late-Phase Burnout, Tools: Reduce Evening Cortisol [2:01:35]
For late-phase burnout, characterised by morning exhaustion and nighttime stress, focus on reducing evening cortisol levels. Avoid bright light, caffeine, and stress, and practice long exhale breathing.
Age, Male vs Females, Lifespan, Cancer; Menopause; Brain Health [2:08:02]
Cortisol secretion patterns are similar in men and women until about age 40, after which women tend to have lower basil levels. As people age, the morning cortisol peak tends to flatten, which is associated with lower lifespan and poorer outcomes in chronic illnesses like cancer. Maintaining a high morning cortisol peak and a steep decline into the afternoon is crucial for longevity and health.
Zero-Cost Support, YouTube, Spotify & Apple Follow & Reviews, Sponsors, YouTube Feedback, Protocols Book, Social Media, Neural Network Newsletter [2:13:41]
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