Definitely! I do a diaphragmatic breathing warmup every morning of 10 min and I try to speak with a diaphragmetic breathing as much as possible. Especially when I feel the tension is high or I anticipate a block, it really helps me to get through better. As I mentioned in other threads, a lot of the intensive speech courses (Del Ferro and McGuire) evolve heavily around this breathing concept and has proven to work for a lot of people.