I've been out of college for about 5 years. Ran a p.r. of 3:52 for the 1500. I have been running off and on for the last few years, more often off than on unfortunately. I am about 20 lbs heavier than I was in college. I'm sure my legspeed is shot, but can it come back? Do I have a chance in hell of perhaps hitting a personal best if I dropped the weight and got serious?