Water intake confusion

[Head Guardian Sophiles Phylax]

The kidneys are responsible for processing the water flow in the body. So yes, they do invest energy into processing water, but they also benefit from hydration as well. More energy is gained by the state of proper hydration than is lost by regulating the water in the body.

In a similar manner, the stomach spends energy breaking down food, but then it regains this energy afterward. If one is especially weak, they can take precautionary measures as to eat smaller meals or easier-to-digest foods. With the kidneys, one can also drink less in one sitting to reduce the strain on homeostasis.

As far as specific amounts, I no longer like to think in certain quantities of water. Instead, focus on urine color and maintain clear or yellow, perhaps using the restroom every 1.5-2hrs or so. Water requirements vary based on one's constitution and other factors that make it hard to give a strict amount. Just make a habit of consistently drinking a little bit every hour or two.

However, these things are very minor. Really, one should focus on actions that result in large increases in physical energy, such as yoga or pranayama. You may lose 10 energy from drinking too much water, but then add back 100 to the kidneys from your yoga session, for example. It is important to keep such a perspective on things, although it can be hard because we cannot always easily quantify it.