If you ever had any doubt about the effectiveness of exercise on the condition of your body have a look at this - a number of women athletes taking part in age-group competition in the Crossfit Open 2017, all of them over 50 and the oldest of them in their sixties.
There's a lot of talking so the parts to watch - the amazing women athletes themselves - are at 1' 10", 1' 50", 2' 45", 3' 45", 4' 40" and 5' 30".
So after watching that, how do you see yourself in the future? Do you see the inevitability of gradually losing all of your physical capacity? Will life after 50 just be thinking wistfully about all the things you used to be able to do, all the things you wish you had done now that they are beyond the capabilities of a 50, 55, 60 year old?
Are those things beyond the capabilities of these women - clearly not!
Put some effort into taking care of your body and your body will take care of you.