Orangetheory Fitness Mercer Island plans to host its first Open House Anniversary party from 4-6 p.m. on March 30.

Orangetheory Fitness offers a scientifically designed, 60-minute, heart rate based interval group training workout of cardiovascular and strength. The workouts take place in a group setting on treadmills, WaterRowers and in the weight room.

Members wear a heart rate monitor to accurately interval train, while logging results in real-time. Participants burn an average of 500 total calories per class and continue to burn calories post workout.

All ages 14 and up and fitness levels are welcome. Qualified coaches inspire participants to push themselves to their personal best so to reach their fitness goals. Working out in a group can provide camaraderie, support, accountability and structure.

Orangetheory Fitness Mercer Island invites anyone to a free introductory class. A schedule is available online and anyone can call 425-278-5709​ to book their first class.