Adding a session on a day that has none
Your plan doesn't fill every day, and sometimes you want to run on one it left empty. Ask, and your coach can add a session to that day — an easy extra run this week, or something before your plan officially starts.
This is different from changing a session you already have. If the day already holds a planned workout, your coach edits that one instead of stacking a second on top.
It arrives as a card you accept or reject. Nothing lands in your plan because it was mentioned in a reply — you see exactly what is being added, and it only becomes real when you accept it.
Your coach may say no, and that's the job. An extra run in the wrong week is how a good plan comes apart. If adding it would compromise a key session or a recovery day, you should expect a reason and an alternative — a different day, or a shorter, easier version — rather than a flat refusal.
If a whole day is empty and the plan has nothing coming up, your coach can also propose filling it unprompted.