Does This On-Trend Breathing Exercise Work Against COVID19?

On the 3rd April 2020, a breathing exercise was demonstrated by Dr Sarfaraz Munshi, an urgent care lead at Queen’s Hospital in London, through a video uploaded on Youtube.   https://www.youtube.com/watch?v=HwLzAdriec0&feature=youtu.be   The breathing technique was intended to help coronavirus patients reduce the chance of contracting secondary infections/pneumonia with these simple steps:  Take a deep breath and hold it for…