Just finished my 5th marathons. I got a new problem: my heart rate was not high, I felt great, but my leg muscle gave up only after the first 8 miles or so. I had the feeling that if my muscles were strong enough, I have no problem keep the same pace for the whole race or even had the chance to run a negative split.
In all my previous races, I was able to push after 20 miles and beyond; though my legs would be sore and tired but the bottleneck was my overall reserve of stamina.
About my training, I largely use Andy Palmer's with a flavor of Hansons at later stage with mileages ranging from 65-85 mpw. However, I had no other training/exercise than running, and never had any stretching or core training.
My question is: to overcome the muscle weakness, should I include any specific training, such as hills (including downhills) and core strength training.
My next race is 2014 Boston, and my goal is 255 (with a 10 minutes PR). Thank you!