Updated: Dec 17, 2018
Sometimes I want to learn a little more about a topic but I don't want to commit to a weekend course, a whole book or a PubMed search. This is typically when I'll turn to podcasts. Podcasts are a great way to dip your toes into a topic before you decide to take the plunge.
I've read my fair share of sleep books but I still learned something from each of the following podcasts. Here are my notes. Hopefully you'll learn something as well.
Chris Kresser’s Revolution Health Radio Podcast with Harpreet Rai
Who is Harpreet Rai? Harpreet is the CEO of OURA Health. OURA Health manufactures the OURA ring that tracks sleep, HRV and physical activity.
There are so many choices for wellness tracking and wearables these days. I'm a bit biased attributing much of my success in overcoming years of on/off insomnia to the information and changes that the OURA ring helped me make. They recently came out with a new version and Chris Kresser interviews their CEO.
How is the OURA ring different from other fitness/health trackers?
The OURA ring is focused on sleep. Clear correlation between health and sleep (chronic disease and longevity) but also in the short term: Sleep is the best performance enhancing drug out there.
Why focus on sleep?
1/3 of population gets less than 6 hours. Over last 30-40 years the amount of sleep we get as a society has dropped by one hour. There is a link between sleep deprivation and several if not all chronic diseases.
Sleep is a form of checking in. The OURA ring is an awareness enhancer. It helps remind us to pay attention to what is needed for behavior change.
The benefit to using technology to track your sleep is:
immediate feedback on changes you may have implemented the day/night before.
How does the OURA ring do this?
In addition to looking at percentage of time spent in the different phases of sleep the ring measures your heart rate variability (HRV)
HRV not just about assessing performance readiness. It is one of the best objective ways to measure stress response.
What is HRV? The inter-beat interval variation of your heart beat and an indicator of how you are dealing with stress. Low HRV is more tied to chronic disease and higher insulin resistance, higher fasting glucose levels. Low HRV is leading indicator for stroke and heart attack. Also an indicator for short term stress.
How does the ring measure HRV?
OURA rings sample heart rate throughout the night. They feel using a ring is the most effective way to do this for a couple reasons. The skin in your hand is extremely thin. The arterial pulse in your finger is 50-100X stronger than your wrist (which is more of a venous pulse)
Sampling occurs with Infrared light shining at 250 Hz: (compared to 10-26 Hz on most other wearables)
Recently published abstract in the medical journal Sleep showed that OURA HRV compared to EKG is 98% correlated
Measuring HRV during the night reflects the accumulation of stresses throughout the day and gives a clearer signal of HRV. There is a cycle: Your night will be the mirror image of your day. So stress management during day is critical for a good night's sleep. Likewise, how you sleep at night sets you up for success on how you'll manage your day.
Benefits to OURA
Gathering metrics for health and wellness is complicated and likely filled with some amount of error. Comfort, ease of use and accuracy are the OURA rings purported strengths.
OURA uses infrared light compared to most other wearable that use green light. Green light is disruptive to your sleep. No LED indicators in the ring (like smart watches have)
For those that are concerned with EMF/wifi the OURA ring has an airplane mode and will store data up to 6 weeks before syncing. The amount of EMF is relatively small as compared to other devices. If you think about energy transfer. The OURA ring has a 15 mA battery and lasts approx a week and an iPhone battery is 50x bigger and lasts day.
Sleep is a systemic issue.
We often have to examine some deep core beliefs about who we are.
Sleep is a behavior and behavior change is difficult. We need to examine core beliefs and not expect changes to occur with just providing education/information.
“Well, if you’re not getting enough sleep, you’re not the best version of yourself the next day.”
Dr. Bubbs Performance Podcast with Chari Mah, MS
Who is Cheri Mah? Cheri Mah is a research fellow at the University of California SF (UCSF) Human Performance Center. She consults elite athletes and professional sports team in the NFL, NBA, MBA and NHL and in her free time is finishing up her 4th year at UCSF to obtain her medical degree.
Why is sleep so fundamental to human health?
1) Sleep has been engrained in our DNA for eons.
2) Sleep has multifaceted effects:
Cognitive (for athlete: impacts reaction time, attention, decision making)
Physiology (impair metabolism, affects hormone regulation: appetite and testosterone)
Immune function affected : more susceptible to illness with inadequate sleep
Physical performance: studies suggest physical decrements with inadequate
She emphasizes its not just about sleep duration ( but quality of sleep and chronological strategies)
Recommendation of average healthy adult: minimum of 7 hours - but individual sleep needs vary
Recommendation for High level athletes: 8-10 hours
How much you think you are getting can be quite different than what you are actually obtaining. ((go read notes from Chris Kresser podcast!)
Focusing on improving your sleep should be done with gradual changes. (add a half hour at a time, shifting bedtime to earlier is easier than shifting wake up to later for most)
Chronic sleep habits most important; athletes often struggle with sleep the night before a big competition.
Some studies show that that sleep banking might help in preventing some of the decrements that come with times of inadequate sleep
Young adults have a delayed body clock where they naturally want to go to bed later. Early morning training sessions may not be the most productive sessions. Schedule periodic recovery days (sleep in am) has shown to benefit recovery in athletes (specifically stress scores)
There is a definitely an impact of travel and time differences on performance and observed circadian misalignment between east and west coast teams.
Rule of thumb is that it takes one day per hour of time zone that you cross to re-acclimate your body clock
Tends to be harder to shift your clock going eastward because our body clock is slightly longer than 24 hours and we always need that exposure to the sun to lock our body clocks into our time zone
Best if you can travel with adequate time before you have to play or perform
NFL study looked at 25 years of night game match ups between east and west coast teams. Regardless of the coast that you are playing on. If you simply bet on the west coast team you'd beat the point spread 68% of the time. Reason why is that body clocks differ. Regardless of the coast where the game was played the west coast team was playing on 3 hour earlier body clock- Late afternoon is time when performance is typically enhanced.
Strategies to deal with jet lag
Most advantageous to prepare in advance.
Pre-flight strategies- Start to shift your body clock a couple days before you fly, go to bed a half hour earlier, sunlight exposure to influence body clock. Get adequate sleep before you travel.
In flight strategies- try not to nap so maintain a sleep drive that will facilitate a transition to new time zone, hydration is key is mitigating the effects of jet lag
Post-flight strategies- Mah is a fan of power naps of approximately 20 min. Timing is important for these too. She recommends in the afternoon because that is when we have a natural dip in our circadian clocks. Its easier to fall asleep. Timing can depend on when you want to have increased performance.
Too long of a nap will cause sleep inertia- a grogginess because you woke during deeper stages of sleep. May also decrease your sleep drive and affect your subsequent's night sleep
Naps should be used as an energy boost but not replace adequate sleep
The Caffeine nap (also called a Napaccino): you have to be sleep deprived to fall asleep quickly (within 5-10 min)
Consume your caffeinated beverage
Fall asleep quickly
Power nap 20 min
Nappaccinos have been shown to be more advantageous than just caffeine alone or just napping alone.
Nutrition: recommends a protein and complex card pre-sleep snack for athletes after games and to decrease fluids an hour before bed.
Nutrition research is starting to show effects on sleep architecture. Timing of meals can benefit sleep and is a significant strategy for mangling circadian clocks
How much sleep do you need? The amount of sleep we need doesn't change as we age but the type of sleep does change. Males in particular start to see a decrease in the percentage of deep sleep
Regarding the application of sleep science, there are 3 buckets to focus on
Sleep Quality (stress the wind down routine)
Timing of Sleep
Dr. Moira Junge and Dr. David Cunnington interview Professor Sean Cain
Who is Prof. Sean Cain? A PhD who is on faculty at Harvard Medical School studying circadian rhythms as they correlate to sleep and the impact on cognitive performance.
Circadian rhythm influences more than just sleep and wake times. It influences many things including mood.
The relationship between circadian rhythm and mood may help direct potential treatments for depressive symptoms and maintaining healthy moods.
Patterns observed between those with lower moods and going to bed later.
Sean Cain published on this.
People undergoing treatment with SSRIs for depression who were evening types had more depressive symptoms and more suicidality. They identified a phenotype that did not respond well to these types of anti-depressants
Circadian rhythms are hidden, under the surface and can't be assessed just by looking at sleep/ wake times. They are hard to measure. Hence they can be difficult to manipulate properly.
There are some types of treatments that can harm people with depression more than help them and it’s because of these hidden effects of circadian rhythms
What components of circadian rhythm impact mood?
-the phase/timing of the rhythm (ie, time of day) - esp in relation to sleep -wake behavior.
For example your melatonin onset in the evening is important. If your melatonin onset is 2 hours before your chosen bedtime, that's usually the optimal circadian time to go to sleep.
-amplitude of rhythms (the strength of rhythm) is a reflection of the strength of the signal for your body clock control your sleep-wake cycle but all the other systems that change over the day
Emerging research on circadian rhythms and depression:
Some early research shows that phase delayed individuals are more prone to depression.
Non-optimal sleep that often comes with phase delayed sleep results in disturbed emotional regulation and therefore gives us a more negative bias causing us to perceive negativity more easily.
Phase delay results in a push of your core body trough (your core body temp minimum). This should ideally occur 2-3 hours before you wake. So phase delayed individuals have a really hard time waking up because during the time of your core body temp minimum occurs when body clock has the strongest signal to sleep. This affects your ability to maintain alertness and positive mood all day long.