Hey guys this is my first post so I will give you a little background info. I am 6'1" 230-235lbs and I am in the next 2-3-4? months going to be taking a physical for a police department in which I have to run 1.5 miles in 12:29.

I am pretty active and today I ran on a treadmill about a 9:30 mile. After running I was reasonably out of breath but I definitely could have gone longer. I understand that I need to run at about a 2:00 per 400m pace to get to where I need to be. I need suggestions PLEASE!

My thinking is that I should run 400m "sprints" where I keep my pace in and around 2:00 and do 6x of them taking short breaks in between at first and then gradually working out the full mile and a half.

My fear is that I am going to run into joint trouble (Which I had during my college lacrosse days at times) if I push it too hard too fast. Thanks to everyone for their suggestions!