Pace while training

I am training for my first marathon but have been an off and on runner for about 10 years. I see in all of the training books that it says that you should run your long runs at 1 to 2 minutes per mile slower than your goal marathon pace. My goal marathon pace is about 7:30 per mile. Right now I am up to training runs of 14-15 miles and am having no trouble covering the distance

Treat your training as your race. Try to run at your actual pace withount forcing oyur body to put more.

Just take care of injurires.

Hope it helps