The Best Breathing Pattern in the 100 Freestyle by Gary Hall Sr., The Race Club February 23, 2018 | 0 minutes, 27 seconds read The 100 freestyle is not a sprint and requires a steady flow of oxygen intake, more so on the second 50 than the first, in order to maximize the performance. AEROBIC VS. ANAEROBIC The human body is equipped with two systems to produce energy for fast swimming, aerobic (requires oxygen) and anaerobic(no oxygen required). Both are used in tandem to produce ATP, the fuel for our muscles, but there are significant differences between the two energy systems that you should consider when choosing a breathing pattern for a specific race. Read the rest at The Race Club sports in this article Swimming tags in this article Training & Drills