When asked how the body repairs itself and replenishes its resources, most people will answer with one word: sleep. They’re mostly correct.
When you drift off at night, your brain and body take a much-needed vacation from the stress of living. Organs rest, muscles repair, immunity rebuilds, inflammation levels decrease, and the brain undergoes a sort of housecleaning that removes some of the toxic byproducts that naturally accumulate during the day.
Neuroscientists and sleep experts know that healthy brains essentially switch on and off throughout the night, toggling between one-second periods called upstates, when brain activity is high, and downstates, when brain activity is low. The consensus is that these downstates are responsible for sleep’s restorative benefits.
I’ve long been fascinated by this nightly voyage of repair and rejuvenation. As the director of a sleep lab, I spend my days witnessing the negative cognitive, emotional, and physical fallout experienced by people whose days are so packed with work and stress that they totally skimp on sleep, or who try to go to bed at a reasonable time only to struggle with unrefreshing sleep, middle-of-the-night awakenings, and insomnia. Without sufficient high-quality sleep, every system in the body suffers, from memory to heart health to immunity.
Getting your sleep in order is of utmost importance, of course, but there are also many things you can do during the day to refill your metaphorical gas tank in ways that are just as re-energizing and rejuvenating.
What is the downstate?
Borrowing from the upstate-downstate phenomenon that happens in the brain during sleep, I use the term downstate to describe the many activities and habits that accomplish the same rest and repair as the ups and, more importantly, the downs that occur all night long.
Downstate activities are simple ways of recharging via food, exercise, breathing, nature, and, yes, sleep, so you can squeeze the most activity, productivity, health, and joy out of each day.
Downstate activities promote autonomic balance, a healthy balance between the sympathetic nervous and the parasympathetic nervous systems.
The sympathetic nervous system is responsible for the fight-or-flight response that kicks in during moments of stress, as well as for all the thinking and doing that happen during the day. I call it rev.
The parasympathetic nervous system is the rest-and-digest system that calms you down, decreases inflammation, replenishes depleted resources, and supports mental and emotional processing. I call it restore.
The relentless pressure of life has most people revving too high and too long, with too little time and energy spent restoring. This is called autonomic imbalance. Pervasive in American culture, it’s responsible for premature aging, worsened memory and cognition, weakened immunity, and a host of chronic diseases, including heart disease, cancer, diabetes, and obesity.
Anytime you do something to help balance your autonomic nervous system, you are tapping into the power of the downstate, promoting healing and repair at a cellular level. Fortunately, there are downstate opportunities everywhere you look: You just need to know where to find them. They happen when you sleep, yes, but also when you practice mindfulness and focus on your breathing, take your dog for a walk in the sunshine, hug a loved one, or finish a challenging workout.
Ready to rebalance your nervous system and utilize your body’s natural healing powers? Try these three downstate activities.
Morning cardio workouts
When you get your heart pumping and body sweating, rev is in control. Post-workout, a series of processes designed to reverse all that wear and tear begins in an effort to give restore the upper hand: The heart rate slows, muscles relax, and body temperature drops. This signals the initiation of numerous recovery processes. Cells are flooded with reparative nutrients, levels of the stress hormone cortisol drop, and neuroprotective hormones that stimulate the growth of new brain cells are released.
Regular exercise also greatly enhances sleep. Just one session of moderate-intensity exercise increases time spent in slow-wave sleep, a critical phase of sleep during which the majority of our restorative functions take place.
It also improves heart rate variability (HRV), the amount of variation between heartbeats. High HRV is a recognized indicator of autonomic balance. It’s also linked with improved cognition, lower rates of heart disease and diabetes, healthier weight, and a better ability to tolerate stress.
So why morning cardio? The process of fully returning control from rev to restore takes nearly a day. If you work out early, this transfer of power will reach its peak effect during sleep, boosting your natural repairing, rebuilding, and replenishing powers. Morning exercise also gives your autonomic nervous system enough time to recover, unlike nighttime workouts, which can leave you so energized that it worsens sleep.
Limiting eating times
You’ve heard the phrase “You are what you eat,” but it turns out when you eat is just as important. Our ancestors hunted and gathered during the daylight hours and retired once the sun went down. Thanks to the invention of the lightbulb (and, more recently, the internet), we now stay up way past nature’s intended bedtime, often eating as we scroll or watch television.
But our metabolism and digestive organs aren’t designed to work late at night. During the day, the body can effectively and efficiently process nutrients, fats, and sugars. But at night, it longs to be in “rest and digest” mode, just like restore itself.
Pulling out a bag of chips at 10 p.m. reignites rev. Sugar from your food will stay in your blood longer and is more easily stored as fat, and your sleep will become fractured because you’re turning on bodily processes that were fully prepared to be in rest mode.
People who routinely confine their eating period to a shorter window—usually eight, 10, or 12 hours—give their bodies that much-needed break, improving HRV and restoring autonomic balance in the process.
Ease yourself in with a 14-hour window. After a week, reduce the window by one hour. Ten hours of eating a day is a reasonable goal for most people. You choose the start and stop times, such as 8 a.m. to 6 p.m. or 10:30 a.m. to 8:30 p.m. This is commonly called intermittent fasting or time-restricted eating.
In a study by renowned circadian scientist Satchin Panda, PhD, patients with metabolic syndrome, a cluster of conditions including high blood pressure, blood sugar, and cholesterol, plus excess belly fat, were instructed to restrict their eating times to 10 hours for 12 weeks. There was no calorie restriction. At the end, they saw their weight, waist circumference, blood pressure, and cholesterol drop, and their sleep improve.