In my 20s, sleep was never an impediment to travel—I could get in from a flight at midnight, be home by 2am, and still be at work on-time, bright-eyed and bushy-tailed. Or I’d try to save money by getting the 5am flight no one wanted to be on—set an alarm for 2am and start my day there.

But in my late 20s and early 30s, something shifted. A bad night’s sleep meant feeling like a zombie—numb to the world and not fully mentally present—which is not a way I wanted to experience new places.

I thought it was just practice I was lacking—and if I got more used to being in different time zones, surely my body would adjust. But I think part of getting older is your body slowing down in different ways. I can still climb a hill and hit 20,000-step days, thank goodness. But the thing that I need most for a good trip is a good night’s sleep. Why?

Without proper rest, I’m starting my day like a car who’s gas tank is only half-full.

I’ve written before about how resting is the most productive thing I do while travelling—a piece that’s mostly about me battling the need to rush and instead, pace myself. But the foundation of rest is sleep. If I don’t fall into deep REM, when I get up I’m sluggish and tired—not at all the place I want my body to be if I’m exploring somewhere new.

Everything gets harder without enough sleep.

Executive disfunction goes up when I’m tired and irritable; that’s the brain function responsible for making decisions and taking action. Where I’ll eat lunch, whether I’ll walk or take public transit, whether I want to do a tour or explore on my own—all of these become headache-inducing questions when executive dysfunction enters the chat.

Memories don’t get made when sleep isn’t happening.

I’m not just talking about how worse travel days mean that you might miss out on special moments. Sleep plays a pivotal role in turning daily events into long-term memories. Remember that movie, 50 First Dates, where whenever Drew Barrymore fell asleep her short-term memory got wiped?Imagine that, but you never remember a trip again…that’s a horror movie. Not to mention that a big part of travel for me is learning, and poor sleep leads to lack of focus (meaning it’s harder to process new information) and memory retention problems.

Stimulants only help so much, and can lead to crashes later.

I’m not a big coffee drinker—it tends to upset my stomach, and even when it doesn’t, can lead to me feeling jittery and anxious. This feels like trading one problem for another—either be exhausted and slow-moving because every step feels heavy, or be wide-awake and unable to stop a speeding heart rate. Neither of these feel like great options for a day of sight-seeing, especially when coffee usually comes with an energy crash and an exhaustion headache later.

Exhaustion can make bad mental health days worse.

According to Mind.com, a lack of sleep can make certain mental health conditions worse. Those with persistent sleep issues are more likely to feel anxious and depressed; to feel lonely or isolated; to struggle to plan things, make decisions, or concentrate; or feel irritable and not have energy to do things. Any one of these things would be enough to put a damper on a day of travel!

Good sleep means bouncing back quicker.

Getting back from a trip and being well-rested—or coming home and being able to catch up on sleep—means you’re ready for your next trip sooner!

Travel isn’t just about days in a new place; it’s about learning, making memories, and being present. All of these things get so much harder without sleep, as does caring for your mental health. Taking care of your mental health is so important while travelling, and physical health can directly impact that. So be sure to include “a good night’s sleep” in your checklist next time you travel!