unfit leader to do GSR to raise money for Scouts

So I'm an assistant leader with a Scout group I've been with for over 20 years and an Explorer unit and I'm pleased to say that

5 Scouts and 2 Explorers have been chosen to go on a once-in-a-lifetime trip called Project 23

This is a 3-week expedition in the summer of 2023 going to 3 campsites in Austria, the Czech Republic and Germany to undertake scouting-type activities, meeting Scouts from other countries, sightseeing, other adventurous activities that we can find, and some pure fun activities.

So I have been talked into doing the Great South Run after just recovering from Covid for the 2nd time in a year this is a 10-mile run (maybe walk) that I will be trying to complete with the help of one of the Explorers to try and raise some much needed funds for the Scouts to help offset the cost of the trip