I'm Morris Brossette, and this is how to strengthen your lungs for underwater swimming. I'm going to give you two tips to strengthen your lungs so you can swim longer under water. The first and most important is to learn to breathe diaphragmatically. may be familiar with this if you've ever taken yoga. What I mean by diaphragmatic breathing is instead of when you take a breath in, the chest rises and you exhale the chest falls, by a diaphragmatic breath I mean when you inhale your stomach and diaphragm expand and when you exhale, the diaphragm contracts. When you take a shallow breath in through your chest, you are only using 10% of your lung capacity. The other remaining 90% is actually below the chest. So when I'm breathing in like that I'm only getting 10%. So what I want to practice is take in a full diaphragmatic breath and then I'll try to hold that for 45 seconds, 50 seconds, a minute, whatever my limit is and I'll do this just like I would a strength training regimen. I'll do one set of 45 seconds for example, then I'll rest for about a minute and then I'll repeat that two more times. I'll do that once in the morning. I'll do it once in the afternoon and then I'll do it once in the evening. So three times a day I'm working on one deep diaphragmatic breathing to really get the most of my lung capability and then two, I'm working on holding that length of breath.