Transition from Half to full

Matiakez

Hi all,

 

Just after a few tips or pointers really.

 

So last year I completed my first full marathon in Edinburgh with a time of 3 hours 10 minutes. In the subsequent six months I struggled with a string of injuries which dated back to fall on my ankle back June.

 

Anyhow I entered Edinburgh and accounting for a few hairy moments have reach the stage of tapering having conducted relatively decent mileage. I also completed the Sheffield half back in April in a time of 1 hour 25 minutes. On my long runs however I've consistently been short of steam past the stage of 16/17 miles, this is despite conducting things at a largely comfortable pace. In my second to last run my shoulders and upper back began cramping up and breathing was less than comfortable, so much so that having on numerous occasions threatened to give way my legs simply gave up the ghost half a mile or so from home.

 

I completed my final 20 yesterday and whilst it wasn't nearly as dismal there were signs of things cramping up again. It's difficult to pinpoint what is going wrong this time around given that I've done very little different to the training program that saw me through last year and that also accounts for nutrition.

 

Having initially targeted a time of around 3 hours I'm now less than confident of beating last year's effort. Has anyone else found it a real struggle to transform themselves from a solid half marathon runner (my PB for the half is 1 hour 21) to a solid marathon run?