In reply to DR:
I used to live in Glasgow, there's lots of great hill running nearby. In the Campsies Dumgoyne, Earls Seat and Cort Ma Law are all good runs. As well as the Whangie and Duncolm hill from Old Kilpatrick. There is also a nice run up Croy Hill and the Antonine Wall near Kilsyth.
Further afield you've also got the Luss Hills and the Trossachs.
Ben Lomond and the Arrochar hills are also doable for an evening after work run in the middle of Summer with the light evenings.
Highly recommend the Westerlands who are a very friendly fell running club in Glasgow. Their website will probably be a good place to start for route ideas too.