This goal has the following fine print specified by coolhandlouis:
No minimum amount of time or effort, as that can depend on my health. My goal is about three times per week but one time out of three can be substituted since something can come up where I just can't make it to the gym. This emphasizes long-term commitment and consistency would rather than any amount of time or effort since I tend to overdo it, burnout, and stop going. So I want to make it easy on myself to be able to accomplish this goal. Informally, my goal is at least 10 minutes to 30 minutes per session, but even that is not absolutely required.