The Peter Attia Drive, Episode #126, with Matthew Walker

“One of the problems with alcohol is that it’s a sedative, and that what most people think of as a benefit of a nightcap is not really a benefit. Yes, I would say you lose consciousness faster. When you put yourself into bed, it’s hard to say you’re putting yourself into natural sleep. Your sleep becomes more fragmented, because the alcohol will actually stimulate the fight-or-flight branch of the nervous system. It also releases weight-promoting chemicals. That’s why you wake up more frequently. And the third part is that alcohol will decrease the amount of REM sleep you get, particularly toward the middle and the later hours. And of course, what you said there, what is happening, very understandably, that you are trying to find a way to manage your anxiety.”

So, to recap:

  • Alcohol is a sedative

  • The nightcap is NOT a benefit

  • Alcohol makes you lose consciousness faster

  • Alcohol does not induce natural sleep

  • It makes your sleep more fragmented

  • PREVENTS restorative sleep

  • It stimulates the fight-or-flight branch of the nervous system

  • It releases weight promoting chemicals

  • It makes you wake up more frequently

  • It decreases the amount of REM sleep you get

  • It decreases REM more toward the middle and waking hours

To extrapolate, alcohol would therefore, in almost every way, be completely counterproductive to all physiological recovery, both for the brain and for performance.

Causes insulin resistance

Causes gout

Disrupts sleep

Is a toxin

Is expensive

Causes oxidative stress in cells

The Institute of Human Anatomy

YouTube Video

  • The liver

  • is the second largest organ in the human body

  • can regenerate itself

  • The Brain

    • Gray matter is where the neurons communicate with each other

    • Billions of connections

    • Neurotransmitters

      • Dopamine

      • Serotonin

      • Gamma Glutamate

    • Alcohol lowers inhibitions (occurs in the brain)

    • Alcohol disturbs the decision making faculties

    • Hypothalamus

      • Secretes hormones that control the pituitary

      • Ethanol present, signals to the pituitary to release adrenaline

      • Slows down the release of ADH (vasopressin), which works to maintain blood pressure, water volume in tissues, and blood volume.

      • This causes you to lose more water than you are drinking: peeing all the time

      • Dehydration

      • This also means that the kidney is also excreting a lot of electrolytes

      • Lowered ability to rehydrate

      • Urine is just liquid that used to be blood.

    • Pituitary Gland

    • HPA Axis: These two structures control your entire hormonal system

    • Alcohol disturbs hormonal function

  • Protein Synthesis

  • Alcohol prevents proteins from being built inside the skeletal muscle tissue

  • Stimulates Sympathetic Nervous System

  • Females are affected more dramatically than males, due to higher body fat %

  • Acetaldehyde is more toxic than the ethanol itself

  • The liver converts it to acetate and the lungs excrete it

The New England Journal of Medicine

Effect of Alcohol (Ethanol) Administration on Sex-Hormone Metabolism in Normal Men


To determine whether ethanol per se affects testosterone metabolism, alcohol was administered to normal male volunteers for periods up to four weeks, resulting in an initial dampening of the episodic bursts of testosterone secretion followed by decreases in both the mean plasma concentration and the production rate of testosterone. The volunteers received adequate nutrition and none lost weight during the study, which tended to exclude a nutritional disturbance as the cause of the decreased testosterone levels. The changes in plasma luteinizing hormone suggested both a central (hypothalamus-pituitary) and gonadal effect of alcohol. In addition, alcohol consumption increased the metabolic clearance rate of testosterone in most subjects studied, probably owing to the combined effects of a decreased plasma binding capacity for the androgen and increased hepatic testosterone A-ring reductase activity. These results indicate that alcohol markedly affects testosterone metabolism independently of cirrhosis or nutritional factors. (N Engl J Med 295:793–797, 1976)



Volume 23, Issue 6, June 1974, Pages 921-928

Effect of ethyl alcohol on plasma testosterone level in mice


The effect of ethanol ingestion on testicular steroidogenesis in mice was evaluated by measuring plasma testosterone level. Four groups of CBA/J male mice were treated with one of the following doses of ethanol: 1.240, 0.620, 0.310 or 0.155 g ethanol/Kg body weight. A control group was given water. The data showed no effect of the treatment on testicular weight. The concentration of testosterone in the plasma was significantly reduced in animals treated with alcohol. There was also a significant relationship between the dose of alcohol and the plasma testosterone level, with the decrease in testosterone being from 2 to 18 fold in various groups.


Heart rate variability (HRV) and resting heart rate are two of the most useful metrics for quantifying your fitness on a daily basis. Consuming alcohol causes your HRV to drop (bad) and your resting heart to rise (also bad).