It's never too late. There's exercise for every level for what they want to do. Not everyone can be a ballet dancer like Marianne. The local YMCA often has swimming programs, elder fitness programs, and plenty of things to get involved in. The key is getting there and starting, recognizing that it's never too late.
Some people have perfect health, and some people have diabetes, heart disease, and osteoporosis.
How these people exercise is really different, both in what types of exercises they do and how much they do. It's important to see your doctor before starting a program so you can get the most out of exercising.