When I was a recruit in the basic military training (aka BMT), the instructors would make us drink a mug of water, approximately 200ml, before every meal. This practice is known as water parade. The reason behind it was to ensure we drank sufficient water so that we would not have heatstroke. Thus before every meal, we would assemble with a mug of water, and with a loud cheer (or rather a toast) we would gulp down the mug of water.
The most challenging water parade during BMT was before the route march. I could not remember the distance we were to cover, it was around 10km or 20km. Before we set off, there was a water parade. We had to assemble with one water bottle that was filled to the brim, approximately 1.5L. The instructors then inspected the water bottles to confirm that our water bottles were indeed filled to the brim. The next step was to finish off the water, and to hold the water bottle upside down over our head to show that the water bottle was empty. I felt so bloated.
The other challenging water parade was during my army vocational training. After our night snack, the duty instructor told us he was under orders to conduct a water parade because we would be out in the field for the whole day on the following day, and the weather forecast showed it would be a hot and sunny day. After drinking a mug of water, we thought it was over. Suddenly the course commander turned up and said 1 mug was not enough. He gave new orders to finish one water bottle of water. I vomited halfway. That night I could not sleep well as I kept visiting the toilet.
Come to think of it, while I understand the need to ensure that soldiers have enough water in their bodies in order to avoid heatstroke, but I really question this method.