More miles would help , definitely . 45 is a great start but it ' s low for marathon peak , especially with a goal of BQ . How many days per week do you run ? Are you following a marathon plan or do you have a coach or do you just wing it ? My general weekly format is to have a midweek mediumlong , a weekend long , and a workout , with 3 other easy days of 57 miles in the schedule in between the quality days I don ' t generally do long runs or workouts back to back . One day totally off . Some people can do 7 daysweek but I ' m not there yet , I need that rest day . If you can work your way up to 45 mpw being comfortable before you start training and then go for a higher peak , you ' ll be in a much better spot to shave off those last few minutes . Add easy miles , add days , don ' t cram too much mileage into a long run while you ' re building your base up .