As the lights dimmed and the instructor got things going, she reminded us that we’d made a choice to get up that morning and put our own health and needs first. “And how often do you do that ouside of class?” she asked. My immediate answer: Hardly ever. For the next 40 minutes, as the sweat rolled and the energy of the class built, I thought about that. About how I had usually put my happiness—myself—last.  Normally, at 9 AM on a Saturday, I’d still be in my pj’s, but I’d agreed to join my friends for an indoor cycling class at SourCycle. I was nervous that I’d make a fool of myself, which is why I picked a bike in the last row, but I knew I had to make a change. My doctor had recently told me that I was prediabetic. Without my size-36G boobs holding me back—I’d gotten a breast reduction a few months earlier—I had run out of excuses for avoiding any and all forms of exercise.  Photo by Cody Pickens And I was mad. Why had I given up on myself so many times? In the back of that dark, sweaty room, I realized I didn’t need to be at the mercy of my genes, staring down the barrel of a life-time of high cholesterol, diabetes, and obesity. I realized, as tears streamed down my face, I had a choice. MORE: The Incredible Women Who Lost 160 Pounds With Yoga Craving that postworkout high, I kept going back. Each instructor would frame how the grit we built during a tough ride could help us face any challenge. There was great music, people high-fiving, and I walked out feeling like I could take on the world—and it was cheaper than therapy. Within 5 months I dropped 30 pounds and slashed my triglycerides in half, and now my blood sugar levels are on the decline. I even quit my exhausting desk job at an interior design firm and applied to graduate schools for physical therapy—something I’ve wanted to do for years but lacked the confidence.  Photo by Cody Pickens Now when I clip in at SoulCycle, I sometimes choose the first row. It’s terrifying for the first few beats of the song, but once if find my rhythm, my anxiety dissolves. I might still struggle to keep up the pace but if I falter, I know that I have the support of the room to back me up. –Jennifer Inaldo, 37, San Fransisco MORE: Everything You Need To Know To Be Happier Now