The following are my notes from the TED Talks Daily podcast, Why sleep matters now more than ever | Matt Walker.

Matt Walker has an impressive set of credentials related to sleep science. View his website at

Notes on Sleep, the Immune System, and COVID-19

Individuals that reported getting less than 7 hours of sleep reported a 3-fold increase of getting the Rhinovirus.

The body requires sleep in order to produce a proper immune response to even vaccines. Studies found that participants in flu shots who had less sleep for the week leading up to the shot had a 50% drop in antibody response.

This means that when the COVID-19 vaccine is released, individuals must make sure they get enough sleep for a minimum of a week beforehand.


Sleep prepares the brain for learning, almost like a dry sponge ready to absorb new things. Additionally, sleep (after learning) performs something like a “file transfer” mechanism where it transfers the learnings from a short-term reservoir to a more permanent reservoir.

Sleep will actually take new memories and associate them with pre-existing stores of information, almost like sleep alchemy.

This leads to a 3-fold increase in creative insights (hence why you’ve been told to sleep on a tough problem).


The quality of your sleep impacts two hormones in your body that relate to your consumption and perception of food:

  • Leptin - hormone that tells your brain when you’re full
  • Ghrelin - hormone that tells your brain when you’re still hungry

When you lose sleep, these two hormones go in opposite directions. The signals from leptin are reduced, so we don’t know when we’re full, and the signals from ghrelin are increased, so we continue to eat even though we have reached a sufficient level of food intake.

Additionally, when sleep loss occurs, the preference for food groups shifts: You start to desire more heavy-hitting carbohydrates and more simple processed sugary foods, rather than more healthy macro-ingredients.

Tips on Enhancing Sleep Quality

  • Keep the room cool before bed and during the night.
  • Keep the lights dim (personally, switching Philips Hue lights to a dim red works well).
  • No caffeine many hours before bedtime. (not from the podcast, but I recommend 6+ hours)
  • Manage your sleep/awake cycle consistently, regardless of if you had a full night’s sleep.
    • If you did not go to bed at a good hour, do not sleep in. Instead, suffer through it for the day, and wake up at the same time every day.
  • Avoid napping to make up for lost sleep.
  • If you’re having trouble falling asleep for more than 30-45 minutes, do not let anxiety take over:
    • Get up, do something away from screens, bright lights, etc (such as reading a book under dim lighting)
    • Do the above until you feel sleepy.
    • This pattern creates a predictable pattern for the body to follow. Instead of associating your bed with a place of stress, only going to bed when you’re properly tired allows the body to properly maintain an effective sleep routine.
    • Sleeping is a bit more like landing a plane than an on/off switch.
  • Consider removing all visible clocks from your room. Knowing the time does not help with managing stress when you’re failing to fall asleep.

Devices Before Bed

We’ve probably all heard this, but using social media on your devices within a reasonable amount of time before bed and after waking up causes spikes in stress. Avoid checking notifications and social media for a minimum of 5 minutes before and after bed for starters - the longer you can avoid it, the better.


Melatonin (Wikipedia) can be used to help regulate the sleep cycle. However, it will not resolve other sleep issues. It is akin to a gun shot to start a sprint race - the gun is responsible for starting the race, but the participants in the race are still responsible for working through the race itself.

7-9 hours of sleep. A small amount of people can innately sleep 5-6 hours. You’re probably not one of them.

Personal Recommendation

From me, not Matt Walker:

  • I recommend a comfortable sleeping face mask as well. I tried a few before settling on the one linked.
  • A fan to create white noise can help cancel out other noises as well as keep your room cool overnight.
  • The website Sleep Like the Dead provides a unique filtering mechanism for actual mattresses.
  • Exercise helps regulate the sleep cycle. Exercising in the morning ensures that you’re tired by the time 8pm rolls around.


  • Reduce sources of anxiety and blue light when it comes time to sleep.
  • Consistent sleep cycles are critical, regardless of how late you go to bed.
  • Sleep promotes weight management, immune response, and problem solving skills.