A run in the sun

Had a day off today and after a wet morning it cleared up and turned into a lovely afternoon. As soon as Neighbours was over (what? everyone watches Neighbours don't they?) I got out for a longish training run. Just over 7 miles and it took me an hour. I'm happy with that at this early stage of training. That's a 4 hour marathon and that's a good pace this early. I must take care though not to get sucked into settling for this pace - its too slow. Maybe I'll do some 400 metre sprints at the weekend. Do any of you guys have any useful tips for making sure you don't settle for too slow a marathon pace?