Respuesta :
Her motivation to running the marathon is so that she could buy something she wants to gain. She mentally has the goal to get the pair of shoes which makes her body want to go towards that said goal.
Answer:
completing a marathon
Explanation:
Sheila wants to buy tennis shoes and run every day, timing how long it takes to run on the school track. She wants to do this to train and be in good physical shape to complete a marathon.
As her goal is to complete the marathon, we can say that this is the motivation for all the effort she is making.