I didn't go to uni in Loughborough or come from there but I live there now.
It's definitely not in the middle of nowhere, who told you that? You have Nottingham, Leicester and Derby all within easy reach and Birmingham is only 1 hour away.
There are plenty of restaurants, night clubs, two cinemas and afaik lots of things going on on campus. I don't know if students venture far as they have most stuff on the doorstep
As a resident I would say that the students can sometimes come across as arrogant, I don't live in the town centre but there are constant issues in the student areas with inconsiderate behaviour. That may apply on other uni towns but wasn't a feature of my home town which has a big unversity.
As a positive I like living in an area with such an fitness feel, my DC have access to all different kinds of sports that are offered at or around the uni. There are runners everywhere, all the students are tall and athletic looking. If your DS does go there he won't need many clothes, there is a standard uniform of tracksuits/shorts and flip flops 
What sport is it that he would be training for, where would his training base be, if he's not spending much time at the uni a lot of this may not be relevant