How many times have you gone to a gym, jumped on an available cardio machine for 45 minutes, the same as you did the day before, or the day before that, or the day before that?
Or, in the alternative, how often have you felt discouraged, feeling like you are pushing yourself, but not seeing what you want to see?
Maybe you are none of those.
Maybe you workout really hard. But, you want to mix it up.