Grand Rapids Small Business Of The Year! Over 25 Years Experience - Certified Professional Staff - Gymco's Accredited Instructors Teach Sports in a Positive, Non-Competitive Atmosphere & Develop Building Blocks for a Lifetime of Fitness & Physical Participation! Free Trial Classes Are Available For Brand New Students!. Pre-Sport Development (18 Mo. - 6 yrs) - All Sports Class (Grades 1-5) - Gymnastics / Martial Arts - Cheerleading - Birthday Parties / Field Trips - Group Adventures / Open Gym