Intervals are important for improving your swimming. Human beings are creatures of habit and generally try to optimize where they can, and so does their body. If you go to the pool three times a week and swim 2 km without stopping, that’s great, and in the beginning, it will get you started. But at some point, you won’t see any improvements anymore. Trust me, this is not only related to technique; it is also related to the fact that your body starts to optimize. Let’s say your first training ses