https://community.usms.org/swimming/f/general/6746/underwater-trainingAs part of most training swims, I do at least 12x25 meters underwater, with 30-45 seconds rest after each 25 to catch my breath. Typically, the 25&#39;s alternate between (a) underwater SDK on my back and (b) something similar to an underwater breaststrokeen-USTelligent Community 12https://community.usms.org/thread/99217?ContentTypeID=1Mon, 04 Aug 2008 03:39:22 GMT3187ac58-ba85-4314-b79a-c45cd885e09a:e44fb371-76bf-4410-861b-2919dcfdbe49Ryknoit&#39;s been awhile, but we used to have a &quot;fun&quot; set of 25&#39;s when I was younger. everyone starts with 10 breathes. We swam 25&#39;s start :30 and the goal was to swim as many as you could with only the 10 breathes. I can&#39;t remember how many I could do back then, but if i were to try that set today, I would be happy if I could get in 15 25&#39;s. the first 5-6 with out a breathe and then one breathe for 8-9 and the last one most likely taking 2 breathes. Thanks for bringing this up, because I think this kind of breathing control is more fun than swimming 3-5-7<div style="clear:both;"></div>