Why is weight training especially important for older people?

That phrase if you don't use it you will lose it stands true. 

It's important especially for older people because there muscles get weaker when they age and by working them out they could be working out a lot more and cardiovascular health raised higher by this. Any old person working out more could even lead to not having any health problems and living a longer life by keeping the body going well.

Bis the answer hope i