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Mental Health

Podcast 131: Understanding Stress and How it Affects Sleep Performance & Cognitive Functioning

July 13, 2021

This week’s episode is a deep dive on stress, including the results of a study on how sleep performance impacts your cognitive functioning.

By Will Ahmed

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WHOOP and McKinsey’s Executive Leadership Program in Australia recently partnered to investigate the relationship between sleep and executive function in the workplace, and what we found was really remarkable.

For every 45 minutes of sleep debt a person accrued, they had a 5-10% decrease in mental control the following day. Conversely, for every 30 minutes of slow wave sleep gained, that person saw a 5-10% increase in mental control the next day.

Dr. Jemma King and Nadia Fox helped lead this groundbreaking research. They sit down with our Vice President of Performance Kristen Holmes to break down everything you need to know about stress and how it affects your sleep, your memory, and your physiology. They also discuss how our brains react to stress, proper breathing and how it can calm your body down, and how light exposure at night affects your sleep.


Stress, Sleep and Cognitive Functioning Podcast Show Notes

3:33 – Studying Stress. “We had this extraordinary opportunity to integrate biopsychological information that helped us better understand how leaders make decisions in the presence of high levels of stress, and then how that stress manifests in WHOOP data. … There is an opportunity to really understand your body and understand how the stresses of day-to-day life influence your cognitive ability.”

5:15 – Evaluating Stress with WHOOP. Jemma explains how she has used WHOOP in her past research and why it was the perfect choice to measure stress, sleep, and memory performance.

11:00 – Managing What You Measure. “It’s really hard if you’re not quantifying aspects of your life that actually have a direct, linear relationship to performance, you’re probably leaving something on the table,” Kristen says.

14:18 – Study Findings. “For every 45 minutes of sleep debt that the [person] accrued, that led to a 5-10% decrease in mental control the following day. … [We also found] that every 30 minutes of slow wave (deep) sleep gained, led to about a 5-10% increase in mental control the next day. So we’re really seeing the benefits of sleep come through.”

16:46 – Major Takeaway. “The idea that just 45 minutes [of sleep] is going to have a massive influence on your ability to make decisions the next day [is remarkable]” Kristen says. “It’s hard to believe that, but it’s true. We were able to prove that in this research. … To understand that sleep debt correlates to working memory and executive functioning, that basically validates the sleep need metric [that WHOOP is] feeding you every night. So when WHOOP tells you that you need to spend X amount of time in bed, if you listen to it, you have a greater chance of waking up the next day and being a better decision maker.”

21:38 – Sleep Consistency. Kristen and Jemma discuss the importance of sleep consistency. “It keeps emerging in all of the research that we’re doing that sleep consistency is really the most important sleep behavior,” Kristen says.

22:49 – Sleep and Performance. “If you want to be a high performer and if you’re not sleeping, you’re kidding yourself because something is going to snap,” Jemma says.

26:55 – Light Exposure at Night. Kristen and Jemma discuss Dr. Andrew Huberman’s findings that if people view light between 11 pm and 4 am, it blocks the release of serotonin the next day. Check out Dr. Huberman’s appearance on the WHOOP Podcast.

30:56 – Stress and Sleep. “We can see that stress can impact how our sleep architecture looks during the night. Pre-sleep stress has been shown to suppress our body’s ability to achieve parasympathetic dominance through the night. [Stress] reduces our slow wave sleep.”

32:47 – The LeBron Approach to Sleep. Jemma quotes LeBron James, who said “A good night’s sleep starts the minute you wake up.”

35:13 – Sleep Behaviors. “There is this epidemic across the world around poor sleep behaviors,” Jemma says. Kristen shares some of the best behaviors you can adopt throughout the day to set you up for a good night’s sleep.

37:06 – Phone Light Before Bed. “You have to be super careful,” Jemma says. Even if you’ve got a blue light filter, we don’t know what the other [lights] are doing to your circadian rhythm.”

38:40 – Breathing and Stress. “If you slow your breathing down, what it does is it hacks into that primitive system and it tells your brain that you’re calm and you’re safe. From a hunter-gather perspective, there is no way you’d be breathing slowly if you were being chased by a bear,” Jemma says. “When we’re under stress, our brains will prioritize survival mechanisms and survival actions over deep thinking. If you’re breathing erratically, and when we’re stressed we have a tendency to have lots of short in-breaths and very little out-breaths, and we actually hold our breath when we’re stressed. This is a survival mechanism. …Think about this when you’re stressed next. Are you holding your breath?”

40:56 – Proper Breathing. Jemma and Kristen discuss how proper breathing can calm you down. Jemma notes that researchers have found enzymes in the paranasal sinuses that produce nitric oxide.

43:56 – Nutrition. “We should look at ourselves like high-performance machines. You wouldn’t put a can of coke into your McLaren P1. You’d get it oiled. You’d service it. We have to look at our bodies in the same way.”


Learn More: Impact of Stress on HRV, Resting Heart Rate & Recovery


Learn more about how WHOOP Unite can elevate well-being for all teams and people.

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Will Ahmed

Will Ahmed is the Founder and CEO of WHOOP, which has developed next generation wearable technology for optimizing human performance and health. WHOOP members include professional athletes, Fortune 500 CEOs, fitness enthusiasts, military personnel, frontline workers and a broad range of people looking to improve their performance. WHOOP has raised more than $400 million from top investors and is valued at $3.6 billion, making it the most valuable standalone wearables company in the world. Ahmed has recruited an active advisory board that consists of some of the world’s most notable cardiologists, technologists, marketers, and designers. Ahmed was recently named to the 2021 Sports Business Journal 40 under 40 list as well as 2020 Fortune 40 Under 40 Healthcare list and previously named to Forbes 30 Under 30 and Boston Business Journal’s 40 Under 40. Ahmed founded WHOOP as a student at Harvard, where he captained the Men’s Varsity Squash Team and graduated with an A.B. in government.