WHOOP VP of Performance Kristen Holmes is joined by Dr. Allison Brager, a sleep expert. Dr. Brager is a neurobiologist and a Major with the United States Army, and her research has covered survival in extreme environments under sleep deprivation and stress. She sits on fatigue management and neuroenhancement working groups for NATO, the Office of the Army Surgeon General, and a variety of government agencies, including the Department of Defense and NASA. Dr. Brager is also a member of the WHOOP Women’s Performance Collective.
Kristen and Dr. Brager discuss how to understand sleep debt and sleep need, what we know about banking sleep before anticipated periods of less sleep, and why fragmented sleep can have such a negative effect on us. They also cover everything you need to know about caffeine and how it impacts the chemicals in your body.
Stay healthy and stay in the green!
3:38 – Defining Sleep Debt. “Sleep debt is different than poor sleep, because sleep debt is basically poor sleep accrued over time. “We think of sleep as a bank account: The more you take out, the more you have to repay.”
5:17 – Sleep Need. Dr. Brager says the international average sleep need is just over 8 hours, but notes that sleep need is extremely individualized. “8.4 [hours per night] is the human biological need for sleep, but there’s a huge standard deviation and standard error with that.”
9:26 – WHOOP Sleep Need. In a 2021 WHOOP study, individuals had a 5-10% decrease in next-day executive function and cognitive control after accumulating 45 minutes of sleep debt.
13:00 – Mindset, Sleep, Recovery & Performance. “The most predictive factor of if somebody will have detriments with their next day performance is if you ask somebody when they wake up in the morning, ‘How well did you sleep?’ And based on their answer, it almost mirrors how they perform.
16:48 – Caffeine. Dr. Brager explains how caffeine works and how it is not a replacement for sleep. “The reason why caffeine is effective is it prevents the release of the neurochemical adenosine. Adenosine is a neurochemical that is released by glial cells that increases as you become more sleepy. What caffeine can do is it can block the rate at which adenosine is increasing, and so thereby it can minimize overall sleepiness. The problem is even if caffeine is decreasing the slope of adenosine release, you still need to make sure that you replenish the system. Caffeine cannot do that. The system has to be replenished through sleep.”
20:28 – Sleep Fragmentation. One of the biggest culprits of poor sleep and the biggest contributors to all the health factors that result from poor sleep is sleep fragmentation,” Dr. Brager says. “People who have sleep disorders, it’s not so much their lack of sleep, it’s their inability to cycle effectively through sleep.”
23:06 – The Cost of Going Sleepless. “There’s almost irreversible brain damage that results from sleep deprivation,” Dr. Brager notes.
28:47 – Sleep and Wake Timing. “The time you go to bed and the time you wake up needs to be consistent. That is optimizing the circadian rhythms. So we have the biological clocks of the body, and there’s one at every single organ. … So even our skeletal muscle has a circadian clock that directly manipulates how quickly we get into restorative sleep.”
35:05 – Eating Close to Bedtime. Dr. Brager recommends eating low glycemic foods if you need to eat close to bedtime, saying sleep fragmentation can be caused by spikes in blood sugar.
37:54 – Mitigating Insufficient Sleep. Dr. Brager suggests napping, Yoga Nedra, breathwork, and heat or cold exposure as options for recovery on days where you didn’t get enough sleep.