zedzded wrote:
And I don't think 1.50 is necessarily overcooking it if your goal is 4.00 hours. If you've done the training, you can go too fast and ease back the 2nd half without bonking too bad. Not sure about the 99% training on a treadmill though?
So you're saying that, at a race distance where almost the entire running community universally agree that a negative split is the fastest way to run, aiming for a 20-minute positive split and running the first half 1:30 per mile faster* than the second isn't overcooking it?! I agree that you
can run a marathon that way, but it's not going to be anywhere near your potential.
As for the OP, first and foremost I agree with everyone else that it sounds a
lot like you overcooked the start. Comparing your overall training mileage to other people is a bit of a red-herring; some people will be able to run a 3-hour marathon off 40 mpw, others will struggle to hit 5 hours. What you need to look at is what
you are capable of running that training mileage.
Secondly, are you using a calibrated footpod on your treadmill runs and are you running it at 0% incline? These two points are crucial IMO. If you're relying on the wrist-based accelerometer in your 920XT to give you pace then it's
not going to be accurate. I know you probably won't believe this, but the fact that it correlates with your treadmill's pace is almost certainly down to blind-ass luck, not the accuracy and reliability of either unit, because they could both easily be 1:00+ min per mile off. Secondly, and in line with your perceptions, yes, running at 0% incline on a treadmill is significantly easier than running outdoors IMO. Ideally you really want to be doing at least some of your running outdoors as a sanity-check.
*8:23 for a 1:50 half vs 9:55 for a 2:10