I have found that the Sense's heart rate monitor struggles most with large amounts of movement, but if you can keep the Sense relatively still, it does a much better job of reporting. That would validate the notions that cycling gets some good returns from the device.
As a recent amputee in the Canadian winter, I have been relying on my bosu ball for steps. I have been using it for years, getting the steps for my Active Hours, but after a horrible accident almost three years ago, I was fairly housebound after getting out of the hospital. As a long time Fitbit user, I felt the need to kill time by getting steps any way I could, which brought me to the bosu ball on a regular basis.
With the bosu ball, laying flat side on the floor, stand on the ball portion, once you get your balance, shift your balance onto one leg and then the other, which gives the Fitbit the impacts it needs to register steps. If you do it in a fashion that acts as good activity, getting your heart rate up. It will take a couple minutes to get your heart rate up to an adequate level for the Zone minutes to register and then when you get up there, lessen the weight you use on either leg, reducing the impact strength, but still enough impact to register steps. The less the impact strength doesn't affect the heart rate monitor as greatly and the Zone minutes go up. Of course, the heart rate will go down, which will take a greater impact to get going again.
On the ball, it takes about 15 minutes or so to get 2,000 steps. It takes a crazy amount of patience, but if you have it, then this is a good way to get steps and until Fitbit fixes the heart rate monitor software, this is a way to get steps and work your heart rate as well.
Moderator Edit: Clarified subject
