I have worked with her a little bit using a 10' leash.
This can be dangerous if she decides to go around the bike. I always used a 6 foot and snugged my dog in tight so he didn't get ideas about going around the front of the bike.
It's not like you can command anyone to poop, it doesn't work with babies, kids, or adult humans. No reason for anyone to think that their dog can poop when it's demanded either. Exercise helps her bowels move, that's why she is more inclined to pass solids when you go for a walk.
Match her. That should work.
Nothing like a good old fashioned Spanish match ! Never fails.