Fitbit Force Wireless Activity : Fitbit work in cycle, do yoga, or other non-step-based workouts

If you cycle, it won't register any steps or activity time. For yoga, strength training, or other non-step activities, the recorded active time or steps will be limited to your arm movement. Not accurate at all. If you use the treadmill, stairmaster, or elliptical, it will work great as long as you're moving your arms.
For Cycle class, so wear  Fitbit flex on shoe which does count each cycle. Google: fitbit flex shoe