An exercise bike is read as a lot of pedalling while staying in the same place. It tends to reflect effort that feels like it is going nowhere, or a routine kept up out of discipline.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.