Running for a Reason

Usually I run for fun but this year I am runnning for a reason,yes I am running for the most prestigious race in town,the Standard Chartered Marathon.The race is for about 750m and there would be around 4000 young runners in it.I've started my weekly pracitise on Sundays.I try to run for about 1.2Km with multiple breaks.Hope by December I should be able to sprint for 750m without a break.