Other times I seem to go really fast without even trying or thinking about it. Dear Louise, Swimming is a simple sport-jump in at one end and get to the other end before anyone else. In the most basic analysis, it's a game of speed.
Speed is the most crucial element in the sport.
The swimmer who swims fastest wins the race. We know sometimes the fastest swimmer doesn't win because he or she wasn't mentally focused on the task. Technically, it is the velocity at which your body moves through the water. If you ask little kids to swim as fast as they can, they throw their arms and legs as fast as possible with lots of effort, but without much speed. They grit their teeth, tighten their arms, hold their breath, and generally fight the water.