I am currently trying to regain some of the lost flexibility in my legs (youth is wasted on the young).
Is it a good idea to stretch and exercise daily, or should I leave a day in between to rest?
Stretching is just like any other form of exercise, it is all in how you do it. I try to do yoga almost every day. Good idea? Yes and no. If I push it hard, it is not serving tis purpose. If I mix an intense day followed by an easy day, it is helpful with my strength and flexibility.
As a trainer I see it every day, people going about their training in an incorrect manor. Look at it like bending wood. If you take it slow and steady, you get flexibile. If you puch it hard, you will eventually snap.