The doctor will prescribe you medicine to take in order to combat the sickness that has taken over you. That is mandatory.
The only recommendation you would receive will be in the form of - "Take some time off from work" "Eat a lot of oranges" "Try to stay in bed" "You should rest more in the next few days".
Training sessions are not mandatory - You can either have them or not. The game "recommends" (The idea is to remind you really), that you do them.
Also I previously explained how the text is misleading and we would like to change it.
To quote myself: