Sorry everyone for posting in the wrong area.
Just to clarify (maybe I didn't ask the question with enough information) I do NOT ask her to run full out for the entire duration of a 5-7 bike ride, nor do I ask her to run for a solid hour of throwing a Frisbee. On a bike ride she will be mostly walking or trotting with only maybe 6-8 minutes of actual running. Frisbee is much the same, we walk to a park then play Frisbee, then walk home. Door to door of 1 hour. My question was more regarding a full STRIDE, not running full out all day, she doesn't seem to stretch into a full length stride when she is running at her fastest.
To answer gvc, I started her with Frisbee at 6 months. Not running, but getting her used to playing with a Frisbee or tennis ball. Biking, I have a small track in my back yard that I taught her to chase me on at 6 months. Started with walking, then trotting, then at 14 months allowed her to run for short periods. I am being very cautious not to push her too much too soon as I know that growth plates may still be an issue until 18 months.