Ive been stuttering for as long as I can remeber(40Yo) I would consider it moderate to extreme but its improved over my years. I used to see a speech therapist and this was the only exercise that's actually helped. I hopefully explain this correctly lol . Start by taking a deep breath, when beginning your sentence exhale and let the words role off along with the exhale. The idea is that it exercises your breathing . Please dont take this as the "fix" ,I just wanted to share for what works for me . I have been working in finance for almost 18 years..to this day I loath presentations but this exercise helps breathing and getting my 1st few words out.