I once had a friend who was out of sync with her inner rythm ... so to speak.
After identifying the problem, we've sat down for an hour and I've taught her how to breathe properly, especially - but not only - slowly.
It changed her life ... with a catch.
People noticed she was calmer and happier. People liked her more. She got promoted. She started earning more. Her life improved significantly, for months.
And then it hit her. Her ego inflated so much, she started overworking herself. She lost her sense for her limits. Her ego couldn't handle the relative increase in energy, which got even worse due to the relative increase in self-confidence.
Burnt herself out. At least one month hospital.
Breathing techniques are no joke. When you're doing it "wrong" all your life, the sudden increase in energy when you begin doing it "right" can be both quite massive and very lasting.