There is a whole lot of truth in that i must say. It is not only about people saying that but it is medically proven correct. Stress weighs out your body organs, system, and most importantly your muscles really feel it and soon just weigh out.
A friend of mine once asked why soccer managers of big club names look so old compared to their real ages? Then he answered himself and said it is because of their stress. The pressure on them to win games and the stress involved in managing such clubs. Which to me was very correct. The thing is, every living thing requires rest and calm for your body systems to rest so that they can function properly but a man suffering from stress hardly gets enough rest or very little. He overworks and over pushes himself and that wears him out much faster.
You need rest and a peace of mind to stay healthy and young, it is an undeniable fact because most people nowadays who are so stressed out look really old in terms of their real ages and old people on the other hand look even younger and healthy when they are stress free. It is very practical and evident in society and that is why people with stress issues have a low life expectancy because of their wearing out. Stress wears you out in ways you cannot imagine.
Stay stress-free, live healthy and remaim young