When it comes to losing weight or building muscle, it’s best not to go it alone. “Start slow and hire an expert,” said Milwaukee-based CrossFit instructor Dan Martin. Luckily, Kansas City gyms are filled with trainers experienced in everything from yoga to boot camps, all hoping to make their city one of the fittest in America. These six in particular make exercise one of the most rewarding activities in Kansas City.1. City Gym | 7416 Wornall Rd.Fitness specialties: They offer group training during classes for cycling, Pilates, boot camp, and other disciplines.Instructor spotlight: Hailee Bland-Walsh is the gym’s owner and a former professional soccer player. She holds several ACE certifications and specializes in TRX suspension training.Pro tip: Join the outdoor running club for even more exercise camaraderie. 2. Zona Yoga | 8741 N. Dixson Ave.Fitness speciality: You’ll find vinyasa and hatha yoga classes for adults, children, and expectant mothers.Instructor spotlight: Co-owner Kelly Colln has completed 1,000 hours of education and is certified to teach therapeutically.Pro tip: When the instructor says “take a vinyasa,” she means to go through three poses (maybe plank, chaturanga, and cobra) as part of a sun salutation. 3. TheGYMkc | Multiple LocationsFitness specialties: Get more personalized attention in small-group personal training, with class options ranging from boxing and self-defense to Zumba.Instructor spotlight: Mike Dale, a former college football player, now teaches self-defense and serves as a motivating personal trainer.Pro tip: Membership grants access to all three locations and their facilities, from the showers to the vending machines. 4. Brookside CrossFit | 701 E. 63rd St.Fitness specialty: This gym features a 2,700-square-foot CrossFit “box” filled with fitness equipment and open space for strength and endurance training.For beginners: They’ll learn proper form and technique for constantly varied exercises, such as weightlifting.Pro tip: The gym schedules six classes Monday–Thursday, five classes on Friday, and one class on Saturday. 5. HealthRidge Fitness | 17800 W. 106th St., OlatheFitness specialities: Enjoy the 1/8-mile indoor track, outdoor pool, racquetball courts, and cardio machines, plus more than 80 exercise classes a week.Instructor spotlight: Learn from master trainer Chris Branham, who holds a bachelor’s degree in motivational psychology along with certifications in CrossFit, personal training, and more.Pro tip: After a workout, visit the onsite spa for a hot-stone massage. 6. Boulevard Yoga & Healing Arts | 215 Southwest Blvd.Fitness specialities: Three classes are designed to ease stress and increase flexibility: beginner’s yoga, gentle yoga, and vinyasa yoga.Instructor spotlight: Jennifer Kieltyka, who’s practiced yoga since 1990, has followed her studies to Colorado and India.Pro tip: Boulevard supplements its yoga practice with massage therapy and acupuncture.