For strength and toning, inner leg lifs, squats, lunges would be good. leg press, hamstring machiens
at gym might be ok... provided that you do low weight, high reps otherwise you'll build too much muscle to be a long distance runner. So maybe just have really light weights if any at all for leg lifts, squats, lunges.
Abs: ex 1: lay down on your back and keep your legs together then raise them to a 90 degree angle then back down to the floor without touching it.