hi all I broke my back last year and have been in training for 2 months for a 5k race which I did yesterday in the scorching heat at a bad time of 35 mins, I am booked in for a half marathon in march.

trouble is I suffer achilles tendonitis as I ahve flat feet, I run in specially asessed trainers for road running.

I cant run more than 4-5 miles in one go at the mo, I loose my breathing pattern sometimes and it all goes down hill and I lack stamina. I have been working speed and hills into my routine and I dont run more than one route for longer than 2 weeks.

I am looking to build my time per mile up and increase stamina.

First thing is to get over the 4-5 mile limit. Try going much much slower for the first few miles then see how it goes

After two months training and recovering from a broken back that is bloody good going!

Work at your form over a shorter distance till you can comfortably manage a shorter run at a faster pace while still maintaning correct form. I think this would be especially important for you considering your history. Once you can achieve this start going further and further. No big jumps in pace or distance and all should be well.