hey

maintaining a relatively slow pace for first 5 kms in the key ( thats what i experienced some days back)

i do this -

0- 5km -> slow - try 1km in 5.5-6.5 mins

5km - 10km -> increase speed -try for1 km in 5 mins

10km -16-17km -> just keep the pace - at around 5 - 5.5 mins per km

remaining - just think of the joy to finish - u will get a good pace authomaticlly

this will help u complete in 1hr 45odd mins