If you want to see this in action, the next time you face a willpower challenge, deliberately slow your breathing to about 10 to 15 seconds per breath, or four to six breaths per minute. An easy way to do this is to exhale through your mouth slowly and fully with your lips pursed as if you were blowing lightly through a straw. By slowing down your breathing like this, you can increase your heart rate variability and instantaneously boost your willpower and ability to resist the effects of stress.