You needn’t worry. All you have to do is park your car a reasonable walking distance from the spot where you will be fishing and call the walking to and from your car your exercise.
If a cop tries to book you for this - highly unlikely - just tell them you will challenge and report them to their boss and if they proceed they will be wasting everyone’s time for a zero outcome.
Of course you wouldn’t be able to travel halfway across the state and back for your exercise as most reasonable people would consider that unreasonable. We shouldn’t be using our roads unnecessarily as road accidents use up medical resources.
