I only run at race pace in, er, races. The only time I run at, or faster than, race pace is doing intervals on the track. When I race I give it my all and, if I'm not in pain, exhausted and knackered after racing, then I know I haven't given it my all. Once you're more experienced, you'll get to know your race pace and realise how much faster you can run in a race than in training.