Faceoff: Sleep vs. Fitness

Sleep scientist Matthew Walker explains why it’s not a choice.

It’s January 15 and you’re two weeks into your New Year’s resolution to get fit. You worked on a report late into the night, but that’s no excuse to hit the snooze button—it’s time to hit the gym.

Or is it? Not according to extensive research conducted and evaluated by sleep scientist Matthew Walker, PhD, a professor of neuroscience and psychology at UC Berkeley and the director of its Sleep and Neuroimaging Lab—and author of The New York Times best seller “Why We Sleep” (Scribner, 2017). Even occasional sleep loss taxes a multitude of physiological systems, undermining mental and physical performance. Walker shows how chronic lack of sleep undermines cardiovascular health permanently, for example—so run all you want, but you’re still 200 to 300 percent more likely to suffer a heart attack or stroke in your lifetime, compared to people who get adequate sleep.

What’s more, getting enough sleep has benefits that almost seem too good to be true. It’s the magic pill for weight loss, vitality, mental prowess—even learning physical skills more effectively—and yes, happiness. Walker says he is on a mission to help people understand what he calls a “singular, non-negotiable” fact: “Short sleep equals a shorter life.” So 24Life asked him to answer some burning questions we all have about sleep and fitness.

24Life: We all can relate to occasional or extended periods of not getting enough sleep, and the health effects described in the book are dramatic. Can we compensate for sleep deprivation?

MW: People need to understand that sleep is not like the bank, and you cannot accumulate a debt and then hope to pay it over the weekend, which is what many people believe. If you’ve been doing that for many years, you won’t get back what you lost, nor can you undo the risk that you have essentially put yourself in to this point.

However, it’s never too late to change. I say that scientifically because there is evidence, for example, in people who are in mid-life and older adults who had been suffering from a sleep disorder called sleep apnea. They had been undiagnosed and they were diagnosed with the disorder, and then they were treated. Now, some of those people adhered to the treatment and some didn’t, and researchers tracked them across 10 years. What they found was that those people who had been having bad sleep all along but now had corrected their sleep ended up staving off the onslaught of memory decline and dementia by almost 10 years, relative to those who continued to suffer from their disorder untreated.

[But] it can be you just deciding to finally prioritize what Mother Nature took 3.6 million years to put in place, which is something that we call 8 hours of sleep a night. If you embrace that, celebrate that, and prioritize that, you can at least prevent any further degradation and damage. So there is much reason to prioritize. There is much reason for hope.

24Life: Can eating right and exercising counteract or prevent some of the negative effects of being underslept?

MW: We know if you’re eating right but not exercising, or you’re exercising but not eating right, you don’t have the appropriate health outcome. So it’s not one or the other. The same is true for sleep. I used to say that sleep was the third pillar of good health alongside diet and exercise, but I’ve changed my tune. That’s not true. Sleep is actually the foundation on which those two other things sit.

The science is very clear that sleep is the most important thing that you can do every day to reset your brain and body health. If you’re trying to diet but you’re not getting enough sleep, 70 percent of all of the weight that you lose will come from muscle and not fat—because your body is stingy in giving up fat when it is underslept. [And if you’re thinking] “But I’m eating right, so I can get away with a lack of sleep,” well, that’s not going to give you the desired outcome.

The same is true for exercise. Firstly, if you’re not getting sufficient sleep, your motivation to actually just do any exercise is considerably lower. Secondly, even if you manage to get out the door and go out for a run or go to the gym, the intensity with which you work out will be significantly lower and therefore the return on the investment will be far lower…. The third thing is that when you are not getting sufficient sleep and working out, your injury risk escalates. [Waking up early to] get your workout in so you can stay awake for as long as you can is counterproductive. You’re going to get injured, based on the evidence.

I am not suggesting that people stop exercising or eating right. I’m simply saying that sleep should be as much of—if not more of—a priority…. We’ve had a revolution in people trying to eat more healthily. So I know that it’s not this human defect where we can’t make a change…. We just need to be flexible about sleep and change our priorities.

24Life: How does sleep improve athletic performance?

MW: Sleep actually helps fine-tune and improve motor skills. So the idea of the coach waking the athlete up at 5 a.m. in the morning [actually shortchanges] the brain of some critical motor-skill learning that would be happening at exactly that same time of day. … The refinements of motor memories happens in the brain [not the body]. And the puppet that plays out the improved motor memory or skill is the body. But don’t be fooled, all of the changes are residing within the brain itself.

24Life: What can we do in the workplace and in school to make sleep a bigger priority?

MW: We have to start celebrating and embracing sleep and not be embarrassed about it. … I think the work day needs to be much more flexible to encourage people to get the sleep that they need. … Less sleep does not equal more productivity [as explained in the book].

We can change it in the family context too. I think families, especially of teenagers, can chastise their teens who are sleeping in late. It’s not their fault, because they have a natural tendency to be more evening types as they go through adolescence. … [And] they are desperately trying to sleep off a debt that early school start times have encumbered them with during the week. There is this parent-to-child transmission of sleep neglect that must be broken. We know from surveys that well over 70 percent of parents think that their teenager is getting enough sleep, yet only 11 percent of those teenagers are actually getting the right amount of sleep.

In school systems that have delayed school start times, we know that academic grades increase when kids start sleeping more, truancy decreases, behavioral problems decrease, and psychiatric and psychological issues decrease. Life expectancy also increases because there is a marked reduction in road traffic accidents. Those are all good reasons that we need to embrace sleep in our youth.

Photo credit: Teddy Kelley, Unsplash; Courtesy Scribner