High school gym class can be mortifying. Unless you’re the punk who gets off on pelting volleyballs into pretty girls’ faces, the experience promises unlimited opportunities for humiliation. For many students, the only place more anxiety-inducing than the gymnasium is the pool.

If you were lucky, you went to a high school without swimming facilities. If you were unlucky, you were forced into participating in the most hated gym unit. Swim season meant weeks of sitting in academic classes with skin clogged with chlorine and crispy hair that dampened the back of your shirt. It meant too much time spent in a musty locker room and swimsuits that never really dried, but molded by the end of the semester.

Has school-mandated physical fitness always been this annoying? Suit up and let’s take a deep dive into the history of swimming in gym class.

Janesville Daily Gazette, 1967

A “naked in public” nightmare come to life

In 1885, the Brooklyn YMCA opened America’s first recreational indoor pool and required men to swim nude. Wool swimsuits were potential traps for disease and bacteria, and fibers clogged the pool’s simple filtration system. At the time, nude swimming seemed like the most sensible option (even though incorrect proportions of chlorine had a tendency to burn swimmers’ bare skin).

It wasn’t long before school administrators followed suit. Per their pool management guidelines, The American Public Health Association (APHA) required male public school students to swim nude between 1926 and 1962.

cutanduncut.tumblr.com | Ines Vuckovic for Dose

After pools installed more advanced filtration systems, swimming nude became redundant. The YMCA and public schools phased the practice out in the 60s and 70s, but it lived on longer than was strictly necessary. It’s possible these administrators thought nude swimming built cohesion between young men, fostering a bond through mutual chagrin.

The negative emotional consequences of swimming nude

Unsurprisingly, mandatory nude swimming had a lasting impact on its unwilling participants. “Could there be a more frightening scenario on Earth than forced skinny dipping at school against your will?” Bill Flanigin blogged in The Huffington Post.

Apparently not: participants remain haunted by the memories and many still write or post on chat threads, seeking comfort from fellow sufferers. NPR commentator, Robin Washington, attended a Chicago public high school in the 70s. His story of swimming naked at school sounds like a scene ripped from an 80s comedy:

“The school’s folklore included the tale of Coach Valentine using a lifesaving pole to remedy an embarrassing moment of a backstroking swimmer. The coach swatted him on the midsection and shouted, ‘Get that periscope down!’”

The only two people to ever have fun in a high school pool. | It’s A Wonderful Life

Nude swimming also left room for hijinks. Tilmon Brown attended school in Mobile, AL during the late 1960s and he has positive memories of swimming in the buff. “I can remember one day the girls’ P.E. teacher was out sick and they had a substitute that didn’t know the routine. We boys got naked, rinsed off and skipped roll,” he said in an email to dose.

“We jumped in only to find the girls were already in the pool swimming. You can imagine the mayhem that ensued.”

Pool-related pranks were not gender-specific: my mom attended a public high school in Chicago during the 60s and according to her, girls did their fair share of peeking through the pool door cracks to spy on the boys.

Douglass College, 1970 | New Jersey Digital Highway

A maroon one-piece in a world full of green one-pieces

Unlike their male counterparts, women were always required to cover their bodies during swim lessons. The 1948 State of Illinois Public Health Association pool management guidelines stated that ladies had to don plain tank suits to preserve their modesty. Even so, women experienced their own unique forms of humiliation.

The Chicago public school my mom and aunt attended in the late 60s required them to wear swimsuits color-coded by bust size. Women with 32-inch chests wore maroon, 34-inch chests wore navy, 36-inch chests wore red and women with 38-inch chests wore green. Our family is historically flat-chested and my mom and aunt always wore maroon.

“Even though you’re with peers, when you’re 14 and have to wear a suit that reflects bust size when you’re flat chested and look like a 12-year-old boy, it’s embarrassing,” my mom said. She added:

“We all had to wear the same sack of polyester, but I was still self-conscious. The girls who were more shapely still looked good in their red and green suits — and they were the ones with boyfriends.”

I can empathize. I didn’t have it as rough as my older relatives, but no one escapes the swim unit unscathed. My insecurities began in the locker room where I changed in front of more developed girls. The decaying one-piece I borrowed from my older sister did little to cover my nipples, and I dreaded the walk from the locker room to the pool where the boys sat on bleachers, waiting.

For women, self-esteem takes a hit during the swim unit. Body image issues aside, female biology makes swimming complicated. If you didn’t swim for a few days and sat on the bleachers instead, everyone knew you were on your period. And period stigma is no joke, folks.

Just keep swimming

Today, the idea of students swimming nude is unfathomable, thanks largely to our society’s obsession with modesty and sexualizing young bodies. Still, swim gym continues to provide fodder for high school horror stories.

Maybe you escaped slightly disgruntled and celebrated the day you could finally return to curling your hair. Maybe school swimming is a memory that stuck with you for well over forty years, chafing you like an ill-fitting suit. Regardless of your swim experience, we are all united by our mutual distaste for this odious — but necessary — physical fitness unit.