My coach is giving me the choice to do 1600 at 5k, 2x400 at a mile, 2x300 at 800, and 600 at a 3k pace. Each of these will have 2-3 minutes rest.
Another option he gave was four miles of alternating 800s between 5k and marathon pace. For background, my last workout was 3x 600 at 5k, 500 at 3k, 400 at a mile, 300 at a mile, and 200 at 800. The one before that was 2k at 10k, 400 at 3k, mile at 10k, 400 at 3k, and 800 at 5k. I'd like to see a wide range of opinions on what workout I should do.