Hello, My Name is Stan, & I've just learned to swim a month ago, I've been a long distance runner for about 30 years.(since I was 14.) I recently Injured my back early this year, so I had to learn to swim to stay in shape. i'm VERY limited in my swimming. i.e.: the only stroke that I know how to do is the freestyle, and I cannot tread water. I can swim about 60 yards non stop. then I rest from two to three minutes, then I swim another 40 yards I repeat this process until I've completed 400 yards/meters. I swim at the Middeltown N.Y. YMCA. the pool is 20 yards/meters. I joined U.S. Masters Swimming to receive some help in improving my stroke, stamina, & technique. As well as to learn how to tread, and some other types of strokes. Any help that you can give is GREATLY appreciated.