Your plan
Changing your goal time
On a race plan, open Manage Plan and tap Goal time. Pick the new time and save.
Your plan is rebuilt around the new goal from today, and your goal pace follows it. Until your runs give a race fitness, your training paces come from your goal too. Once you have a race fitness, your training paces come from it, so a new goal does not move them.
Plan tab, MANAGE Plan, Goal time.