Age should never be a hindrance to doing most things and starting exercise later in life actually makes you keep going longer. You don’t have to be “over the hill” after 40 or 50.
There is some evidence that shows a relatively healthy person embarking on his journey to fitness at an older age does not succumb much to wear and tear like his younger counterparts. It makes sense because the earlier you start exercising, especially if you’re a professional athlete or involved in competitive sports, the more inclined your body is to injuries.