I have looked it up and could not find anything. What should I look up? Have you ever heard about heart rate variability? Now that is easy to find. This isn't about homework. You are on a site that is sharing information and in your case you hand it out like people should actually listen to you. You cannot just make made up 'scientific' statements with any science work to back it up. You owe it to fellow travelers to link what you are saying.