If you’re taking a tour, you should be fit enough to be able to cycle around for a few hours at a comfortable pace. Sometimes, stops are a short distance from one another. Other times, we’re riding for 15-20 minutes straight to arrive at our next destination.
If you’re renting a bike, you set the pace and decide how far and how long you want to ride. It’s completely up to you. Know your body and what you can handle.