I don't think I can finish. I need a nap," I panted over my cell phone, my dorky white shoe still clipped into the bike pedal, a gust of wind blowing against me as I stood on Vine Hill Road in western Sonoma County.

"Mom, you can totally do it," replied my teenage daughter. "Just don't puke, because that would be hella gross." I was choking back tears, embarrassed to admit that I may possibly fail.

A complete newcomer to the road cycling scene, I was only 35 miles into a 100-mile bike ride with 2,499 other cyclists in the Santa Rosa Cycling Club's Wine County Century. I had never before spun my wheels farther than 50 miles of mostly mild hills and had struggled furiously on nearly every ride. How was I going to finish this? I had no idea.

My daughter was just handing the phone to my boyfriend so he could come pick me up when swarms of brightly colored spandex-clad men flew past with shouts of "Car back!" and "On your left!" I decided that I had to keep on keeping on. After all, I had made it to the first rest stop after 25 miles, including a decent climb up Graton Road with what I later learned were mostly deflated tires. The rest of the day, I told myself after my tires were full, should be smooth sailing. I hung up the phone and pushed onward.

It had all started on a drizzly, shitty morning last fall. As the days grew cold and short, I was fleeing another failed relationship and recovering from a bout of swine flu. I was mopey, underweight and discouraged from a year of emotional and physical sucker-punches involving my health, more than one suicide and a ridiculously stressful job as a social worker. I peeled myself off of my living room floor, where I had spent the last few weeks wrapped in fleece blankets, hacking my lungs out and assuaging my loss of self-worth with Wes Anderson flicks.

I forced myself to stop in for a chai at my neighborhood cafe on my way to another doctor's appointment, hoping I'd run into someone who could cheer me up. I sat, poorly postured and depleted in a plastic chair while the drizzle outside turned to rain and tore the last leaves from the trees along the train tracks. Everything sucked. I was a miserable, sniveling wreck.

My friend Chris Wells, an always upbeat Midwestern ball of sunshine, arrived by bike, grinning from under his rain slicker. He pulled up a seat next to me. "Oh, man!" he blurted. "You don't look so great."

Desperately fishing for encouragement, I explained that I had to set some sort of tangible physical and mental goal for myself in order to avoid sliding into a winter of solitary doom. I also told him how badly I wanted to start cycling again. I just didn't know how or when to start. My days were full of single-parenting my two daughters and trying to make a living as a depressed freelance writer.

An avid cyclist, Chris sipped his coffee and encouraged me to train for a local "grasshopper" ride in the early spring. After his explanation of the mountain bike and cross bike rides, which sounded too intense for a frazzled little wimp like me, he mentioned the Wine Country Century, suggesting that I train for the road ride which takes place on May Day. Having already convinced myself that I would be confined to a mobility scooter by the time I reached my 36th birthday —cruising my neighborhood clutching a can of Ensure—I still wasn't convinced that I could do anything but complain. Yet I decided that the only place to go was up, and boy almighty, I was going to go there from the seat of a bike.

Like most challenges I am presented with, I didn't exactly start riding with ease or grace. I appointed family friend Jim Keene as my personal trainer. He outlined a plan and encouraged me to first focus on the amount of time I would spend on my bike instead of the actual mileage I might cover. This, he assured me, would increase my confidence and get me comfortable dealing with the often crazy traffic on Sonoma County's backroads.

He suggested 10 hours a week, which seemed doable, until I took into consideration life as a single mom and the approaching winter months. I knew that those weekly 10 hours would surely drop to zero and the healthy diet he recommended would rapidly transition to beer and happy-hour fondue.

My mountain bike had been stolen, and all I had to train on was a salvaged single-speed. I needed a bike. Jim brought me to his shop for a custom fit. The store was generous enough to loan me the fanciest and most delicate of road bikes for my first few months of training. I clumsily maneuvered through the shop, concealing my face from the array of cute customers and their perfect sinewy legs as Jim shouted across the shop, "We need something smaller! She's got short legs and a long torso!"

Next came my fit, where I tried handling the brakes of the Specialized Tarmac with what Jim termed my "smaller than average hands" and repeatedly practiced clipping in and out of the pedals with my new cycling shoes.

I jumped and tumbled into my training with naiveté about my own strength and lung capacity. Starting off in the dead of winter, some may argue, was the stupidest thing I could have ever done. Yet I knew there would be fewer riders out, less cars swerving from vineyard to vineyard with wine pumping through their veins and more opportunities to discreetly cry over bleeding lungs that had just recovered from the H1N1 virus.

A friend gifted me with hand-me-down gear and I stocked up on winter layers before my first bone-chilling rides. I even lined the inside of my shoes with some beaver fur that a friend had brought home from Alaska. I was a warrior against the elements. I was ready to rumble.

I forced friends with decades of riding experience to tolerate my muscle atrophy and self-diagnosed emphysema as I whined and whimpered my way through foggy roads behind them. I coughed and hacked for hours and though I mostly expected severe leg cramps and a sore neck, I discovered that my fear-powered clenching of the handle bars was the worst of it.

I pathetically struggled from Santa Rosa to Glen Ellen in 40 degree weather while my riding partners happily chatted and checked their iPhones. I lost count of the times I had to keep from vomiting. Yet every week, I set sail with riding partners or alone, learning the lessons of chafing and bug-eating.

I also enjoyed the alone time, though I felt plenty of motherly guilt for ditching my children, though I actually didn't ditch them as often as I would have liked. I'd rush home after depositing my kids at school, fill my water bottles and stretch my shiny spandex pants up only to have the school call, asking me to pick up a sick kid. I'd justify my annoyance and determination to get on that bike by remembering that the example of trying new things would empower them to someday do the same.

I attempted to fill my lost riding time by borrowing indoor rollers, which sent me flailing across my living room and crashing into walls. I tucked the rollers away and waited for stomach flus to pass and sunnier days to knock at the door. Without the bike, I realized, I would surely sit still in isolation, demons surrounding my mind like Kerouac's bat-filled cabin in Big Sur. Without the movement and temporary escape the bike allows, no wind could blow through my helmet and remove the cobweb-covered madness that looms there.

And on May 1, there I was, determined to finish those 100 miles in any way I could, teetering between delirium and rush. By mile 50, I had lost count of the hills I had walked rather than ridden my bike up, thinking only of the cookies that would greet me at the next rest stop. I had trained with an obscene amount of candy in the bike seat bag where I should have kept a spare tire, because food was what had truly kept me going.

Over the course of three months' training, I had gained 10 pounds from burgers, milkshakes and beer (including a beer milkshake!), rewards for not giving up when things became more challenging than I believed I deserved. I took every opportunity I could to stuff my face.

I reached the second rest stop puffing through horrible leg cramps and envious of the ease with which male cyclists can urinate while riding. I felt sure that this would be my last stop. I stretched out on the dusty lot near Wohler Bridge and prayed that my legs would not buckle and lock into place. I roamed from piles of cookies to trays of bananas, gulping down a sport drink while cramming M&Ms into my mouth.

As riders with more muscular frames than mine surrendered bikes and hopped into the support wagons that lined the road, I once again considered calling it a day. After all, I had just made it 50 miles! I could pat myself on the back and head home to see my kids—once, of course, I finished the pile of carbs I had just started. Then, the craziest inner voice spoke up and refused to let me quit.

The next leg of the ride, which would end with lunch at Lake Sonoma, kicked me in the gut. The urge to puke grew as I struggled against strong winds, my mind racing and swinging between memories of excruciating childbirth and thoughts of exhilarating sex as riders around me grunted, moaned and sighed in a chorus of sound effects that could have been taken as easily from a hospital room as a porn set.

I began fantasizing about shacking up with Alberto Contador (mostly because I like the idea of shouting "Contador!" during sex) and remembering the soul-shaking spazz-out of labor. My mind swirled around Bob Seger's "Against the Wind" while sex fantasies and painful birth memories helped my numb legs to stubbornly continue to walk and ride—toward more food. Shadows on the pavement revealed a never-ending trail of potholes that may or may not have been hallucinations.

I prepared myself for the possibility that I might actually vomit over the flirty guys who suggested I draft behind them. I called my kids and support crew for more encouragement as the delirium grew. Apparently, I was "bonking" from not eating enough, burning calories like draft cards in the '60s. At the 70-mile mark, I ate again and set out, 30 miles left to ride, the ruthless wind finally at my back.

I next arrived and quickly departed the Alexander Valley School after a gulp of ice-cold soda, heading toward the notorious Chalk Hill Road. "If you did Graton Road this morning," assured a cyclist from Sebastopol who was finishing up his 200k ride, "Chalk Hill will be easy. It's much shorter."

I felt a rush of confidence that was so foreign to me that I was convinced that some New Agey magic was being sent by my West County friends dancing around their May Pole. I charged forward and began to climb the mildest hill I had faced so far. "This is nothing!" I thought to myself. Then, around another corner after a brief decline, the real Chalk Hill climb loomed ahead of me, a monster grade. "Fuck meeeeeeeeeeeeeeeeeeeeee!" I shouted, not noticing the grinning man sneaking up on my left.

Somewhere in those last miles, I stopped doubting myself. As I descended my last hill, I remembered the early years of motherhood when every single day felt like a goddamned 100-mile bike ride. Of course in those days, the luxury of a daylong ride, complete with an array of snacks and support crews, was not even an option. Much as the challenges of parenting throw us daily curveballs, leading us to question our decisions, our strength and our ability to push on through the rough times, this epic ride ended with a sigh of relief, a newfound sense of my inner badass and an unyielding love for the fun, the pain and the utter thrill of cruising through hills, valleys and forests on two wheels with a few thousand others who were presumably riding with the same exhilaration I was experiencing.

As I pulled into the finish line, the cell phone in my jersey pouch began beeping.

"You're a rad mama! I am proud of you!" read the text from my teen. She was right. I am a rad mama. For the first time in years, I was proud of myself, too.

And I really needed a nap.

Send a letter to the editor about this story.