How do I set my workout goal back to Open and have it persist?

The color for my Outdoor Walk suddenly changed to red -- somehow a goal got set for 450 calories. I don't care about calories and I don't have time to walk for that long every day so it's really irritating when it tells me I'm halfway there when in fact I am finishing up. I found the workout app on my phone and can set the goal to Open, but it doesn't persist. It reverts back to the goal of 450 calories again for the next workout.