Float Like a Jellyfish

Did you know jellyfish are the most efficient swimmers in the ocean?

That’s right, they may not look like they’ve got anywhere to be, but wherever they go they use extremely little energy to get there.

When jellyfish swim, they pulse, undulating from the center and moving outward. This movement creates vortex rings of turbulent water that propel the jellyfish forward (check out this nature article for more info, and a cool video). There are two stages to the action—one is the movement itself and the other is the rest in between movements.

While 75% of a jelly’s movement happens during the active movement stage, 25% of forward motion occurs during inactivity. That means that 25% of forward motion requires no energy production at all. This reminded me of the heart—you didn’t think I’d miss the chance to talk about human physiology, did you? The heart has two main phases of movement too, systole and diastole. Systole is when the heart beats and pumps blood out to the rest of the body. Diastole is when the heart is relaxed and freshly oxygenated blood fills up the ventricles. This portion of a heart beat is crucial. The more time the heart relaxes, the more time that blood has to fill it up. It can beat more slowly if it pumps out more blood per beat (think about runners or cyclers with really low resting heart rates). On the other hand, if your heart rate climbs too far above 200 bpm, diastole shortens too much to collect a meaningful amount of blood. After a while, it’s basically ventricular fibrillation, and even though your heart is beating a LOT, it’s not going to be able to get enough blood to your body.

It turns out that jellyfish, hearts, and graduate students all have something in common.

We need rest to move forward, and periods of inactivity can still get us where we need to go. Here are two examples from my own career that came to mind when I considered the swimming habits of jellyfish.

1. Rest—or else.

“We’re not saying you should take 42 percent of your time to rest; we’re saying if you don’t take the 42 percent, the 42 percent will take you. It will grab you by the face, shove you to the ground, put its foot on your chest, and declare itself the victor.” Emily and Amelia Nagoski in Burnout: The Secret to Unlocking the Stress Cycle.
As it turns out, humans need sleep every night, but there can be quite a range for how much the individual needs. There are the “sleepless elite” who are extremely high functioning on just fours hours of sleep a night, and then there are those who naturally crave 10 hours a night—both are within the realm of normal.

There were about seven months recently during which I was getting between four and five hours of sleep. For a while, I felt like I had finally found a way to do it all. I would workout at 6am, go to work from 8-5, run or run errands or socialize in the afternoons, get ready for the next day, sleep a little, and then do it all over again.

Then I started to get REALLY annoyed by my friends. I fell asleep every day around lunch time. I couldn’t focus. I started to have weird, unexplained health issues and aches. It took a doctor’s appointment to realize that my body was begging me to get more sleep. I had been dealing with all this by doubling down into my routine and not letting myself rest, when all my body and mind wanted was a few more hours of shut eye.

I was metaphorically leaping into ventricular fibrillation trying to do more and more, when I really just needed a little bit more rest to be effective. I didn’t take rest, so the rest took me and forced me to slow down.

2. Progress when you can’t move forward

The busy season for my research project is in the summer. We have long days, often between 12-16 hours a few days a week. Though our work is very centered around datacollection during this time, in the summer of 2020 my advisor also expected me to move forward with writing for publications and dissertation preparations. I did not. I’m not quite sure how I spent my time when it wasn’t full of experiments, but I definitely didn’t make progress. It was all I could do to show up and run those experiments. I did what I could. It ultimately ended in a difficult conversation with my advisor, who kindly, but firmly, pointed out my lack of progress.

I felt like I had wasted a year due to my inability to mentally or creatively come to work. I felt so defeated.

Fast forward to today, this spring semester in 2022. I’m finishing up a paper to submit for peer-review, and trying to dive into writing my dissertation. I’ve painstakingly crafted figures that perfectly represent my data, and written paragraph after paragraph about the data and what it means. I couldn’t be where I am in my program today without that doldrum summer. I thought I had made no progress, I thought I had wasted time, but I showed up to do the bare minimum and that added up to something significant. It became foundational for my research project.

I was a jellyfish in between swimming strokes, or a heart between beats. I thought I had wasted that time, and yet I moved forward.

Just like a jellyfish, I don’t have to exert energy all of the time to keep moving. Periods of time where I can only manage minimal movement are still so important to my forward motion, and without periods of inactivity, my brain and body can’t recuperate like they need to. At this point in the semester, everyone I talk to is feeling chaotic and busy. Take the rest, don’t let the rest take you.