This is a state-control tool. It's fast and effective. Reduces stress, boosts focus, and quickly resets your mental state.
It's a form of intentional hyperventilation + breath holding

Sit or lie down. Do 30 fast deep breaths (about 3 in and out per second, in nose, out nose). Hold the last inhale for 10 seconds, then release and breath normally.

During the fast breathing (30 breaths):
You blow off a lot of CO₂
Blood becomes more alkaline
Tingly, or slightly euphoric
Dizziness or floating feeling
Tingling in hands/face
Possible mild “high” or calm
Lowers stress quickly
Reduce anxiety in minutes
That light “buzz” = temporary alertness
Helps reset your state when stuckTrains you to stay calm under pressure
Useful when you feel overwhelmed or anxious

Note:
Always do it sitting or lying down
Do 2 rounds max
Sit or lie down
Don’t force

I do this in the morning, lunch time and in the afternoon before I need to do something that requires focus.