Dr. Jemma King Talks Managing Sleep & Stress to Optimize Performance at Work

Dr. Jemma King_WHOOP Q&A

Dr. Jemma King, who holds a PhD in human behavior, answered WHOOP members' questions via an in-app AMA on the science of sleep, stress and cognitive performance in the workplace.

Dr. Jemma King recently joined our podcast to discuss groundbreaking research she worked on in conjunction with WHOOP. The study investigated the relationship between sleep and executive function in the workplace. Among other things, findings indicated that when a person accumulated sleep debt it led to a decrease in mental control the next day, while increased slow wave (deep) sleep had an opposite positive affect.

Jemma also took part in an AMA with our members to dive deeper into the study, as well as answer other questions about stress in the workplace. Here are some of the highlights.


Question: I just listened to the podcast about your stress levels and cognitive performance study. My question is, what are effective ways to improve the cognitive level given that it is unlikely for the stress level to change dramatically?

Dr. Jemma King: The results of our study showed:

1. For every 45 minutes of sleep debt accrued the night before, the executives showed a 5-10% DECREASE in performance on mental control tasks the next day. When you fail to get all the sleep your body needs at night, you begin to accumulate sleep debt. Tracked by WHOOP, sleep debt is the amount of extra sleep you need tonight because of insufficient sleep on previous nights.

2. For every 30 minutes of slow wave sleep (SWS) obtained the night before, the executives showed a 5-10% INCREASE in performance on mental control tasks the next day. SWS (or deep sleep) is restorative sleep, particular for muscles growth and repair because it is during this stage of sleep that the body produces around 95% of its daily supply of growth hormones.

These results highlight the important role of sleep quality for next-day cognitive functioning. Therefore, one way for you to be functioning at your best cognitively, is to simply get enough sleep the night before. Another key factor in improving your sleep quality is to have good sleep consistency, which is going to bed and waking up at the same time each day. Regulating your sleep routine in this way will help your body follow a regular sleep pattern throughout the night, giving you a better chance of obtaining the right about of REM and SWS sleep.

Reducing alcohol is also a big one, it ruins REM sleep, the mentally restorative part of your sleep, making it hard for you to lay down the days’ memories or learn new skills. Eating a diet high in Omega’s has been shown to increase reaction time and speed of processing, and Vitamin B is good for neural health. Hydrating is also good for cognition and attentional focus. And finally, reduce fructose intake, it has been shown to create a phenomenon called hyperosmolarity, where high concentration of fructose in the cerebral spinal fluid draws water out of brain and capillary cells causing shrinkage and impaired cognitive performance.

Q: How important is this research to get the best performance out of people?

Jemma: As modern workplaces become more technologically complex, workers increasingly need high-functioning cognitive abilities to get the best performance and be competitive in the marketplace. Cognitive skills like mental flexibility, speed of processing, impulse control and working memory are critical to enable employees to think clearly, make quick and accurate decisions under pressure, troubleshoot and find solutions to complex problems, and manage staff.

Our results show that less sleep debt and higher slow wave sleep leads to better mental control the following day. So if companies want the best out of their employees, then they really need to encourage and support employees to achieve a life/work balance because it’s cognitively restorative and can be a competitive advantage. So, activities like high-quality sleep, will lead to happier and smarter employees, and in turn, better organizational outcomes.

Q: What implications does your study have for how companies can encourage their employees to maintain life/work balance?

Jemma: I think if organizations invest in a device such as the WHOOP, it demonstrates a strong commitment to improving employee health and wellbeing. The data doesn’t lie. If employees are over-worked, sleep deprived, sedentary, or not engaging in self-care strategies, the WHOOP data will provide the justification for change.

In my experience, WHOOP is one of the most effective passive behavior modifying tools around. Seeing the impact of lifestyle choices in their data, individuals have a very direct and quick feedback loop to gauge the effectiveness of change, or, the consequences of no-change. The data obtained from WHOOP can benefit both the employee and the organization by providing tangible metrics, such as sleep performancestrain and recovery to inform workload decisions.

We know from a large body of research these metrics strongly correlate with immune function and injury burden. For instance, the data gives employees objective proof of illness or overwork, or conversely work preparedness. For the organization, it can reduce burn-out and presenteeism (employees coming to work when sick), providing more protection for work colleagues and reducing overall absenteeism.

As the negative consequences (financial, physical) of sleep-deprived, burnt-out workforces are becoming more and more apparent, we increasingly see organizations engaging in friendly boost-your-sleep reward programs. These programs are doing wonders at eroding the antiquated but pervasive view that no-sleep and overwork is a badge of honor or a display of commitment.

Q: In your opinion, what has been the most interesting or surprising finding?

Jemma: My grandmother would laugh at this, but just how restorative a good hearty sleep is for cognitive function. When your Gran would say “just sleep on it my dear,” she was dead right. If you are having poor sleep night after night, you are literally losing IQ points and increasing your vulnerability to mental health disruption. I now really weigh up.. “Is that Netflix binge late into the night really worth it?”



Q: How do you feel this applies to those in the gig economy? People such as actors, musicians, etc who have sporadic periods of intense stress lasting up to 18-20 hours a day, and then months at a time of light but constant stress trying to book again?

Jemma: With any population that has a sporadic (high-low intensity) workflow, I like to draw on lessons I gained working with elite soldiers. They too have periods of extreme intensity, punctuated by lower-tempo periods, that are still nonetheless stressful. They would use a cup analogy, in that low-tempo times were used to fill the cup, engaging in recovery and endocrine replenishing/buffering modalities in preparation for when times were intense and depleting (sleep & calorie deprivation, cortisol & adrenaline saturation). WHOOP enabled them to quantify these periods of replenishment, so when in depletion mode they had the psychological advantage of knowing they had the built-up physical resources and resilience to cope.

Q: Have you conducted any research on the effects of shift work? Such as firefighters or other jobs that require 24, 48, or 72-hour shifts?

Jemma: Yes, we have a study in the pipeline at the moment to explore just that! Our upcoming study will investigate the impact of stress and shift work on junior doctors’ executive function and clinical decision making in the emergency department at a Queensland hospital. Understanding individual susceptibility and reactivity to work-related stress is of particular importance amongst medical personnel, as the effects of stress can be detrimental to key cognitive processes required for optimal clinical outcomes.

This research hopes to identify the daily work-related stressors faced by junior doctors and how these may impact their physiological, psychological, and work-based wellbeing and performance. WHOOP also did this nice post a while back on tips to improve sleep for shift workers that you might find interesting.

Learn More: Quantifying the Stress of Medical Training



Q: What is “stress” exactly and is it all bad?

Jemma: Stress can be defined as any type of external stimulus, thought, or change that causes physical, emotional, or psychological strain. Stress is your body’s response to anything that requires attention or action. It’s the signal that says move, act, do something!

No, it is definitely not all bad, there is eustress, which is known as a positive type of stress that can keep you energized. It’s associated with surges of adrenaline, such as when you are skiing or racing to meet a deadline. In fact, there is a heap of research that has found there are some benefits to experiencing short-term or acute stress. It can activate growth in some types of brain cells and give you a small boost in some types of immune function.

As you get psychologically inoculated to stress you can better deal with greater stressors later on, and you are more likely to reach out or have others reach out to you, which is nice. It can also make you innovative, industrious, and productive, provided it not chronic.

What is bad is the intensity combined with duration of stress. Chronic unmanaged stress has terrible consequences for your immune system, digestion, growth, repair, memory and mood, and it is very metabolically expensive to be in a stress state. How you perceive the strain in your life is critical–you will get a different cardiovascular/endocrine profile dependent on whether you think something is threatening or challenging.

Learn More: How to Rethink Anxiety – It Can Be a Sign Your Body is Ready to Perform!

Q: Do you have any suggestions on ways to reduce stress while in the office or during the work day?

Jemma: Hacks to reduce stress at work:

1. Ensure you have at least one positive social interaction that leaves you feeling connected or makes you laugh. Increased oxytocin from social interaction is a cortisol stress hormone antidote.

2. Avoid long stretches of inactivity. Our hunter-gather ancestors were never still during the day and we still possess the same neural architecture where inactivity tells your primitive brain you are either sick or injured, which makes you want to slow-down and retreat (it mimics depression symptoms).

3. Hydrate with water all day, it has a significant impact on HRV.

4. Horizon/panoramic gazing reduces mental exhaustion. Constantly focusing your gaze at a small focal point (phone, laptop, stuck indoors) activates the vigilance/attention reticular activating system in the brain. This system uses a lot of energy and stimulates stress hormones. Several times a day, let your focus dial out to panoramic, long-distance vision. It disengages the vigilance system, uses less metabolically expensive brain cells and reduces stress hormones.

5. Be aware and minimize your negative self-talk/rumination. This creates stress hormones, raises HR, takes up valuable cognitive resources and energy, and negatively colors your life lens. Create a worry hour where you pay attention to the mind nagging and write down concerns (“name to tame”). Preferably do this before a workout, but not too close to bed.

6. Burn off your stress fight or flight chemicals. Reset your primitive brain by doing a quick set of star jumps, brisk short walk (stair case) or vagus nerve reset (three swift thumps to the upper sternum) to pattern interrupt frenetic stress signaling up the vagus nerve.

7. Physiological sigh breath or resonant breathing. This breath calms your sympathetic nervous system, and tells your primitive brain its safe to down-regulate. Breathe through your nose, enzymes in your paranasal sinuses produce a vasodilating/blood-pressure reducing nitric oxide.

8. Nap, particularly if you slept poorly and have an important interaction or big decision to make and you feel tired. A 20-minute or 90-minute nap will improve cognitive functioning, do not wake up in between in slow wave sleep (e.g. after 40 minutes, you will experience sleep inertia/groggy feeling).

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

Q: If feeling stressed at work and overloaded, how do you recommend taking a pause to regroup and get back on track? Vacation or simply a day to regroup, etc?

Jemma: I think when we feel really burnt out and overloaded, we have this perception that nothing but a big vacation or a total retreat from daily live is going to make us feel normal again. But, then you think “there is no way I can take two weeks off now…” and it just exacerbates the feeling overwhelmed. Believe me I’ve been there! What I have found using WHOOP, is that by making small incremental and consistent tweaks to things like my sleep habits, alcohol reduction, meal timing, exercise, Iight exposure, etc, I started seeing more green recovery circles in the morning, which in effect dissipated the level of overwhelm-ment and depleted-ness.

I do however strongly recommend a 3-5 day digital detox, where you are really disciplined and only look at your technology once a day. I have found this to be incredibly mentally restorative.

Q: Can you speak to the correlative extend of the relationship between stress and strain? Since high-strain activities/workouts can act as effective means for stress relief, and stressful situations can increase HR and cardiovascular strain as well, I’d be curious to hear about the findings regarding healthy strain on the body.

Jemma: This is a great question! Yes you’re absolutely right, both stress and exercise lead to an increase in heart rate. Why is one considered positive, where the other isn’t?

The positive mechanisms of exercise are multi-faceted and not only based on an increase in HR. Exercise also increases oxygenation of the brain, it is vasodilating, moves lymphatic fluid through the body, produces endorphins, reduces blood pressure and blood sugar, and it also makes you sleep better and reduces activation on the fear centre in the brain.

Stress also raises the HR, however, the cardiovascular profile of stress, fear or threat is very different to enjoyable exercise. It is vasoconstricting, raises blood pressure, blood sugar, clotting agents in the blood, and you produce stress hormones which impact sleep repair and immunity. So, it is all the associated processes that make stress different from exercise.



Q: Where do you see a role for wearables in corporate wellness going?

Jemma: Wearables are already playing an important role in forward-thinking organizations, for example, the companies (and sporting teams) that are using the WHOOP respiratory rate metric for workforce protection with respect to COVID infection and prediction/detection. If you can have any indication an employee may have COVID prior to symptomology and before they leave their house, it just makes sense to use that data.

I also think the younger generations are much more trusting of having corporations or technology interface with their personal data, bodies and experiences. If elite and tactical athletes, leading knowledge workers or any individual that wishes to operate at a top level don’t use wearable technology, they may be at a significant disadvantage.

Q: Is there any discussion in your research communities about how to safeguard biometric data from corporations? Are there potential drawbacks for the worker if employers can see data like what WHOOP provides?

Jemma: You make a good point, I think the spirit of any organizational initiative like this should be to optimize employee wellness and safety while also maintaining user privacy. There is a natural tension here between advancing the scientific exploration of the human condition and privacy invasion. I can therefore understand why people may feel trepidatious to answer journal items honestly about behaviors that may devalue them in the face of the employer.

This is precisely why we use a model where we only receive employee group-level aggregated data in our research. WHOOP also abides by this model in engaging with organizations–individual data related to specific behaviors is proprietary to the individual and organizations are only able to see aggregate statistics.

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