As someone who has practiced yoga for 40 years and started qigong a few years ago, the advice in the article seems fairly obvious. Still, great to see the article in the front page of HN! I had not thought of deep belly breathing helping calm and relax me during meetings - will try that.
Yup, I do this as part of tai chi and qi gong (referred to as 'dan tian' breathing). Seems to be a thing of the west to take elements of yoga, tai chi, daoism et al, and distill them - mindfulness comes to mind - and as devices they're good, but together they amount to so much more than the sum of their parts, hence the eastern penchant for a 'holistic' approach.
Well, traditional systems take actual effort. You cannot market to the masses if 90% of your customers are going to stop coming after a handful of sessions.
... Unless you do a January promotion, pay the full year and get 50+% off. In that case, the wannabes subsidize the actual students.