Optimal Breathing for Relaxation
From the Dual Drive Pro introduction

Your breathing affects your heart rate.

As you breathe in your heart rate speeds up. As you breathe out your heart rate slows down.

The changes in heart rate from breathing are caused by the parasympathetic (relaxing) vagus nerve.

As you breathe out, your vagus nerve activates. This causes your heart rate to slow and helps you to relax.

Slow, relaxed breathing creates slow, smooth heart rate changes. Slow, relaxed breathing also increases the relaxing effects of the vagus nerve.

Optimal heart rate variability (HRV) is a measure of how smooth and regular your heart rate changes are. Optimal HRV indicates:

Slow, gentle breathing
(optimal oxygen intake at ~10 seconds/breath)

Relaxation

Happiness, love, gratitude

Can be a sign of heart health
(Dual Drive is not a device to improve heart health)

Create smooth regular heart rate changes through smooth regular breathing.

1. Place a hand on your belly (abdomen) and breathe slowly and regularly, feeling your hand move slightly with each breath. As you breathe in the expansion of your belly will push your hand slightly outwards. As you breathe out your hand will move back in.
    
2. Although you are breathing slowly, do not breathe too deeply or you will become light headed.
    
3. Breathe in through your nose (if possible) then out through your mouth, leaving your lips mostly closed as if you were gently blowing out a candle. Each time you exhale is another chance to relax.
    
4. Breathe slowly making the out breath longer than the in breath. Optimally each breath should be around 10 seconds long, but it is fine to breathe more quickly or slowly.
   

Dual Drive Pro

Dual Drive Pro teaches you relaxation and optimal breathing techniques. When you learn and practice these techniques in Dual Drive you can see your heart rate changes and relaxation (optimal HRV) levels. This gives you important feedback as to how well you are breathing and how relaxed you are.

While playing Dual Drive Pro in racing mode, the breath pacer helps you breathe slowly and steadily while the the relaxation dial shows how relaxed you are. Relax and breathe in and out with the breath pacer to raise the dial and power your car.