How many times should u change your workout routine
You dont really need to change things that often. Most important thing is to keep increasing the intensity of what you are doing. Progressive overload is key to improvement.
This only counts when your routine works for your goals ofc.
People tend to get this mixed up. The body doesnt get used to just movements. Its get used to the loads and intensity those movements put on your body. So when you feel its hard for you to keep upping your work intensity, which works towards your goal. And ur body starts to adjust. Then its time to switch it up and put ur body under other kinds of tension and overload.
Others just get bored fast and change things to keep it interesting for themselves. Which is good aswell.