I'm a 32-year-old hobby jogger running ~30 mpw and currently in ~18 min 5k shape. My new goal is to run a sub-5 min mile, which seems tough but within the realm of possibility since I'm more comfortable at middle distance stuff. I'm probably in about 515-520 shape right now.
What track workouts would you recommend? Ladders? Mile repeats? Shorter stuff?
Thanks in advance for any advice.