Prince Harry and the Duke and Duchess of Cambridge attend a training day for London Marathon runners

The video covers an American training day for the charity Heads Together, highlighting the involvement of the royal family—William, Kate, and Harry. It discusses their competitive spirit in a relay race and their participation in the upcoming London Marathon. The video also features support from athletes like Paula Radcliffe.

What is the name of the marathon that the participants are preparing for?

Who is the Duchess of Cambridge currently talking to during the event?