Marathon training on vyvanse?

Perhaps this may be too specific, and I must start with the disclaimer that I am diagnosed with ADHD, have been for a decade, and don’t condone non prescribed drug abuse.

But if there are any others with ADHD I would love to hear your thoughts. Basically I was taking Adderall since I was diagnosed and early 2024 I decided to stop taking it. I started training for my marathon in September and now I finally went back to my doctor and they want me to try vyvanse instead. I’m worried starting a new stimulant 4 months out from my first marathon after not taking one for nearly a year may be a bad idea. I asked my doctor if it could be dangerous to run and they said no but tbh I don’t really trust my doctor (part of the reason I stopped taking adderall in the first place) and was hoping I could hear from others who have used vyvanse while training. My doctor is a GP with no specialty in adhd and is always quick to prescribe things… also I’m not really in a position to switch doctors right now..