What does the Green Swim School emphasize in its training?

The Green Swim School places a strong emphasis on performing an open freestyle turn in its training. This technique is vital as it allows swimmers to transition smoothly from swimming in a straight line to being prepared to swim back in the opposite direction. Mastering the open freestyle turn not only enhances the swimmer's efficiency but also improves overall race performance by minimizing the time spent turning. This skill is a fundamental part of competitive swimming, and focusing on it helps students understand the importance of maintaining speed and momentum during transitions.

The other options, while important aspects of swimming, do not represent the primary emphasis of the Green Swim School's training. High elbow recovery, for example, is a technique used in the freestyle stroke but not the focus for the school. Assisted and unassisted roll from front to back and swimming side glide are also key skills, yet they do not align with the school's specific training priority on the open freestyle turn.