With the 2010 Kaiser Permanente Colfax Marathon only 5 months away, this is the ideal time to start building your training base. During your first couple months of marathon training it is important to take your runs easy and gradually build up mileage. Each week you should increase your mileage by 10%. Base building is all about increasing your body's aerobic capacity. Aerobic training improves oxygen transport to the muscles, reduces the rate of lactate formation, improves the rate of lactate removal, and increases energy production and utilization. To build up your aerobic base you must start with slow easy miles.
Be patient with your body and spend 1-2 full months increasing your mileage. During these base building months your average heart rate should range between 60-80% of max heart rate. The more time you have to build a base the better, so start early. By building up slowly, not only are you increasing your bodies ability to utillize oxygen, but you're also preventing common running injuries. Having a solid base is the best way to drop your marathon times.
Running tips from Denver Athletic Club's Running Coordinator Erin Marston