If your shoulders are high and your breath is moving the top of your chest, you're in a 'Survival Breath' pattern. What is happening as a result is that your Vagus Nerve is being squeezed, signaling your brain to stay in 'fight' mode.
You can drop your heart rate without having to 'try to be calm.' It's pure mechanics. When the diaphragm drops, it creates space for the heart, which signals the brain to slow the beat down.
🎧 Deep Belly Reset
The 30-Second Proof: The Hand-on-Belly Check
Try this: Place one hand on your chest and one on your belly. Take a breath. If the top hand moves, you're revving the engine. Aim to make only the bottom hand move. Do this for 3 breaths. Notice how your jaw naturally unlocks. That is the Vagus Nerve responding to the mechanical shift in your diaphragm.