Suffering a half marathon

Just done the GNR, my first ever race at any distance in 1hr44 and a bit. A Really pleased with the time, much better than I imagined, I ran really well up to 11 miles and then very quickly became tired, weak and finished the last 2 miles quite a lot slower than the other 11, struggling to run really. This change seemed to happen quite suddenly and dramatically. I 'm not entirely sure what's physically going on, but would be very grateful for any explanation and any training tips on how to extend the time I can run at pace for - I'm hoping to do the Paris Marathon next and don't imagine I'll manage a good time if I have to shuffle the last 15 miles.

Cheers,

Ben


Can any one help me underOver the last 2.5 miles

I seem to have a problem at 10 miles too, though im not as fast as you , so would be grateful for advice as well

To run at any distance you have to train at that distance if that makes sense.
For half marathon, I usually include a couple of 15 to 16 mile training runs, and for a marathon will go as far as 28 miles -obviously at a reduced pace.
Fuelling is also important - did you drink enough both before and during the event?
Energy drinks are important for replacing both lost fluid and electrolytes as well as providing a fuelling effect.
Well done on your first half marathon - I did about the same time for my first one approx 15 yrs ago.

This also happened to my sister, with whom I was running - she was fine up until about ten miles, then her legs and her heart rate monitor conspired to force us to take a few short walking breaks. Then she was alarmingly hypoglycaemic afterwards. With a similar amount of training behind me on paper in recent weeks, I was absolutely fine, though hungry for the first few miles.

We think that this was due to a combination of not having developed the ability to burn fat before running out of glycogen and not having enough breakfast.

That's why, for the marathon, long runs are vital. Your body needs to "learn" that you're going to do something as stupid as long distance running and adapt accordingly. It's also the principle behind carbo-loading - making sure your legs are well stashed with glycogen beforehand. This won't see you all the way through a marathon (hence the value of taking fuel on board while running), but it should be enough to see you comfortably through a half-marathon.

Most of the experts say that 20-22 miles is quite long enough for a pre-marathon training run. You don't need to force yourself through the Wall in training.

Cheers, V-rap.