with all respect,
its not clear whether you suggest him to perform 2-3 hour long biking sessions, or if you suggest him to do 2 or 3 rides consisting of 1 hr each.
its also not clear on the number of days you said to bike.
Hmm, I guess I wasn't very clear then?
What I suggested could perhaps be summarised by saying, ride as often as possible, for as long as possible.
but a one hour intense(im assuming HIIT) bike ride is just overkill.
Perhaps, though it depends on what you mean by 'intense'.
I meant that he should put some good effort into it, and not ride slowly.