On my very first day of CrossFit, I threw up. It happened my second day, too. And the third. And pretty much all of the first month. The combination of too many push-ups along with too much running and too many exercises I’d never heard of before turned out to be a pretty terrible recipe for my system. I’m fairly sure that if I had seen a doctor during that first month, we would have had a Very Special Talk about eating disorders. Normally when I’m dealing with so much unpleasantness, I do what most people do: give up. But somehow I decided to trudge on.

For the next three years, I squatted, pulled, pushed, deadlifted, and rowed more than I ever thought I was capable of. There were times it made me feel invincible. There were times it made me feel like a bag of marshmallows. Throughout the highs and the lows, though, I couldn’t shake the feeling that I was an imposter. I truly believed that CrossFit was only for the people with that messed-up gene that makes them go for a run before their own wedding or do squats during their lunch break. I was right.

The floor became my best friend.

Before all that, in April 2009, I was diagnosed with testicular cancer. Up until that point, I was a fairly healthy dude. I was the captain of my lacrosse team in high school. I successfully lost thirty-five pounds postcollege thanks to a dedicated plan that involved an elliptical, a portable DVD player, and The Wire. I cared about what I ate and tried not to tip the scale past the two-hundred mark. With my diagnosis, though, I was told I couldn’t lose any weight. I started to enjoy my now-legal pot prescription and the doughnuts it led me to devour. After several failed attempts to exercise during chemotherapy, I decided that I got a free pass to be as lazy as I wanted to, and, after three rounds of the terrible stuff, I was exactly what you’d probably expect: a bloated, hairless blob of a man with the endurance of a slug.

I didn’t seek out CrossFit. After chemo ended, I moved to a new neighborhood to escape the memory of my illness. I was still operating on a pretty lazy schedule, but I wanted to feel strong again, so I joined the gym closest to my house. It happened to offer CrossFit. While some people may favor easing themselves into and out of things, I prefer to go to the extreme and throw myself in the deep end on a regular basis. After that first lunch-losing experience at the gym, I found out just how deep this whole CrossFit pool was going to be.

CrossFit was unlike any workout I had ever done before. It throws out the traditional-health-club model of machines and isolated exercises and replaces them with a whole-body approach rooted in the real world. Calisthenics, Olympic lifting, and gymnastics combine to form a workout that emphasizes ten basic physical skills: cardiovascular and respiratory endurance, flexibility, stamina, strength, speed, coordination, power, accuracy, balance, and agility. Every day, a new workout (called the Workout of the Day, or WOD) is written on a whiteboard, and everyone in a class completes the same workout no matter what fitness level they’re at.

You won’t find anybody doing calf raises or exercise-ball sit-ups in a CrossFit gym (or “box,” as CrossFitters prefer to call it). Instead, there’s an open room with barbells, medicine balls, rowing machines, pull-up racks, and jump ropes. Compared to the formal atmosphere of most gyms, CrossFit boxes seem downright primal. That’s by design. Your typical CrossFitter wants to zap his fitness tank down to zero by the end of a workout. He’s not content to be just sweaty — he wants to collapse into a heap on the floor. The owners of my former gym comprised the perfect profile of who you’ll encounter at CrossFit: a former professional snowboarder looking for a bigger challenge, a college gymnast trying to maintain his strength, and a female Olympic judo star (well, an alternate) who’s been training her entire life.

There’s a lot of bravado in CrossFit, and that’s part of the appeal for lifelong athletes who can’t stand the idea of spending an hour on the treadmill. Firefighters, police, and military personnel especially love the program because it’s all based on functional movement, i.e., the same types of actions they encounter every day in their jobs. In my early days of CrossFit, I used to try to trick myself into thinking I was a firefighter to get through workouts. Then I realized that was stupid.

The first year was exhilarating. I went from that pukey weak guy with no hair to the huffing and puffing mess who kept coming back. The acclimation period is all about accomplishment. You keep beating personal records in workouts; you’re able to lift more and faster than ever before. You graduate from requiring rubber-band assistance during pull-ups to being able to do a whole set of them on your own without stopping. I began bragging about my lifting numbers, and quickly amped up the frequency of my visits from three to four, then five days per week. Without even realizing it, I became that evangelizing asshole who makes people think that CrossFit is a cult.

It’s not exactly a cult, but there’s definitely an “us versus them” mentality. I remember walking by traditional gyms and laughing at the morons doing bicep curls. I remember hearing people talk about going on runs and thinking how decimated they’d be if they had to do thrusters (a gnarly exercise in which squats are combined with barbell push-presses in one fluid motion) after every half mile. CrossFit felt small and inclusive and fun. The trainers (or “coaches,” as they say on the inside) at the gym I joined eventually branched out and opened their own box. As one of the original members of the new place, I felt some of that ownership too. I was a part of a group and we all pushed each other to work harder and faster and better. We had parties and shared inside jokes about different workouts, and I wondered how I had ever existed before this life-changing program came into my life. Then my knee started to hurt.

407 pounds is too many pounds.

Apparently, repeatedly lifting over four hundred pounds isn’t exactly good for you. My second year in CrossFit was my first as an injured CrossFitter. It was something I had seen a lot in the gym, injury; I’d never really acknowledged just how often it was happening. When I say that everyone gets hurt doing CrossFit, I mean it. Not everyone gets injured to the point where he has to get knee surgery, but I did. I also developed a chronic shoulder injury that to this day, eight months after my last CrossFit workout, is still a constant reminder that maybe a human like me shouldn’t do thirty pull-ups in a row. The messed-up part is that injuries in CrossFit are seen as badges of honor, the price of getting righteously ripped, bro. They’re the penalty for not executing movements with perfect form, but I’ve come to believe that having perfect form 100 percent of the time is literally impossible. I’ve probably done hundreds of workouts and let me tell you, not one of them was ever done with completely perfect form.

If you ask a CrossFit coach, the injuries were all my fault. In a culture that drives you to go as hard and fast as possible, it’s difficult not to get caught up in the hype. You’re supposed to push yourself to the limit, but when you hit the limit and pay the price, you’re the idiot who went too far. That double-standard combination of “no guts, no glory” and “know your boundaries” is pretty much why everyone I’ve ever known to do CrossFit will tell you about their best Fran time in the same breath as describing their worst CrossFit injury.

My injury was just the beginning of my CrossFit downfall. The more tangible factor was the program’s popularity. When I joined in 2009, there were only a handful of gyms in Los Angeles. Four years later, the number is closer to fifty official affiliates in the city. According to a recent article, CrossFit has grown from one gym in Santa Cruz, California, in 1995 to a list that may soon top ten thousand gyms, spanning every continent except Antarctica.

In 2011, The Sport of FitnessTM blew up. Reebok made an investment in CrossFit that resulted in the top prize for the CrossFit Games (the sport’s Olympics) ballooning from twenty thousand dollars to a quarter of a million dollars. All of a sudden, the Games were being broadcast by ESPN and Reebok’s CrossFit commercials were shown on national television during the NFL Playoffs. With new members flooding in every day, the gym I’d helped build started to feel foreign to me. Classes went from having ten people to thirty. Workouts took more time because the space no longer had enough equipment to support all these new CrossFitters, so we had to share everything. Instead of feeling like a small community, it felt like a fad. I had gotten in near the ground floor; now the elevator was shooting toward the ceiling and I wanted to get off.

It wasn’t just the new popularity that turned me off. I had started traveling a lot more for work, and every time I left and came back, it seemed like I was starting from zero. My strength remained, but missing just three days in a row would make me wonder if my endurance was totally gone. That would have been fine in the beginning of my CrossFit adventure, but when you’ve put three years into something, it’s truly demoralizing to feel like you can’t keep up.

I scaled back my Monday-through-Friday schedule to four days a week, then three, then just when I felt like it. I was going less often than I had when I was still recovering from chemo. I lied every time somebody asked me how CrossFit was going. “Really great!” I would say, and then I’d try to remember the last time I actually worked out.

At the same time, my gym continued to transform. As CrossFit’s popularity grew, so did the need for each individual gym to establish itself as a major player. That entailed putting more athletes in the CrossFit Games and, incidentally, not caring as much about the guy who probably never really belonged there in the first place.

After I quit, I didn’t do anything for months. I felt like a failure. I felt like I had let my postchemo self down. I didn’t think I could ever work out hard enough to match the results I used to get from CrossFit, so I figured it was better just to do nothing. Slowly but surely I made my way back to the weight I had reached before I started CrossFit. I saw myself as the same blob, but now with a full head of hair and no excuse for why I looked like I had been artificially inflated.

Last week, I started to work out again, at home. After ten minutes, I threw up. Looks like I’m going to be just fine on my own.