For an ednurance attehle my goal, and theirs, isn't to move as much weight as possible so I would have to train them differently. I would put them on a basic strength cycle with the focus of their training being on endurance training. If I only train them to run 40yd sprints and they are running ultra marathons they would crash after a few miles. Honestly, for endurance attehles, all I would do is train their strength. I would either send them to a (Insert endurance event here) coach or have them continue doing what they are doing if it is working.I can make you stronger, but I don't know how to prepare someone to run 100 miles, other than logging in the miles.