I was wondering how often your dojang focuses on Danjeon breathing? When I was training with my sabumnim, we always included it as a part of our warm up and was curious about others. Since I have been out with injury for a few months, I have been thinking more and focusing on the internal part of the Korean arts (and most Asian arts in general). I had already been familiar with similar breathing and meditation concepts from zazen breathing in Buddhism but never really focused on the ki aspect of breathing which Danjeon develops. I conducted a personal experiment recently. Two weeks ago, at the gym I was working on the bench press using the Smith machine. The Smith machine is a rack where the bar is on rails with hooks at various incremental heights to hang the bar on. This machine allows you to use the machine to keep you in good form, or do very heavy weights alone since you can set latches to catch the weight for you if you fatigue or can't lift it. Ever since my shoulder separation two years ago, I have had trouble getting my bench back up. This night I was at the gym and I was doing a bench press strength routine of 2 sets of 10 reps to warm up with a very light weight (50% of my 1 rep max). Then I moved into a 5 rep set of an moderately heavy weight (70%), then 3 reps of a heavier weight (85-90%) and finally one single rep of my max weight (100%). Then you keep adding small amounts of weight until you hit a new one rep max. On this night, I hit a measly 275 lbs, and couldn't even budge 285 lbs. On this night, the only thing I did was the bench press so I would be fresh. I slept 8 hours the night before and ate healthy that day and allowed several minutes rest between sets. So I decided to try something the next week after that (this past weekend). I was at the gym very late (I have a key) so that I could be alone and in quiet solitude. My plan was to work on dead lifts (using a machine to keep my knees and back aligned properly since I am rehabbing a torn meniscus) and the same bench press routine. Once again I slept well the night before and ate well that day. Unlike the previous week, I didn't start with my chest but rather with the dead lifts. Dead lifts are very taxing, so I didn't think I would have much energy left for the bench presses. After my dead lift routine was done, I rested for a few minutes and set up my weights at the Smith machine and set my catches for safety. I warmed up the same as above, two very light sets. Then I did my 5 set and my 3 set. HOWEVER, I made one change: In between EACH set (including the warm up sets) I did Danjeon breathing for several minutes. Normally as my rest I would walk around to keep from getting cold. On this night, when I hit my set of 275 lbs, which was my former one rep max the week before, I managed to get 4 reps of it! That alone shattered the previous weeks record. Then I moved on to 285lbs, continuing my Danjeon breathing between sets. I moved the 285 lbs for a full rep with ease. I was shocked. So I wanted to see how far I could go. Next up was 295 lbs, and success! Finally I hit 300 lbs for a full rep! By doing Danjeon ki breathing, I shattered my previous weeks record. And if you lift weights, you know 25 lbs added to the 1 rep max in a week is impossible. Typically you are happy if you gain a few pounds on your max over several weeks. Finally, as my last attempt I moved up to 310 lbs, but only managed a half rep (which was very impressive considering the previous week I couldn't even BUDGE 285 lbs. ) So I can only reach one conclusion: Danjeon breathing increased my stamina, focus and strength. From a scientific point of view there can be three conclusions: 1 ) A placebo effect: Much like breaking boards and bricks, the mind will hold you back. If you believe you won't succeed, then you fail. If you have confidence in yourself, you will succeed. The problem with this is I didn't expect to succeed at all, as I knew I would be at a disadvantage because I started with heavy deadlifts. 2) That by deeeply breathing from the abdomen, I was able to provide my muscles much more oxygen to recover than they would normally get from typical rest during exercise. This is very likely, for obvious reasons to anyone who exercises. 3) The final conclusion is exactly what our sabumnims tell us: that by mindfully practicing Danjeon ki breathing, we focus healthy energy, draw it in, store it in ourselves and allow it to flow through our whole being. To a martial artist brought up in the traditional ways, it can only be that by mindfully doing the exercises I had healthy ki and was able to focus it to my task. What do you think? Thanks for reading all this!