jik wrote:
I'm looking at getting my 3k/5k times down to sub 10/sub 18 respectively. my current PR's are 10:23-3k and 18:24 -5k. I run 35miles per week and been averaging that for the last 12 months. what are some suggestions to making these times and what are some ideal sessions that I could incorporate
A lot of people will reflexively say "more mileage," and definitely if you want to reach your potential in the events you name you should work your way up in volume. There are direct aerobic benefits for those distances, and it will also support the more race-specific training. If you are doing 5-6 milers for most of your basic runs, make that 6-7, then 7-8. Adding 10-15 miles spread across 6-7 running days is not all that much. 10-12 miles as a progressively paced long run would be good to get to if you are doing 50 mpw. Most people can certainly improve on 18:30 without much more mileage though. Just know that eventually you are going to hit a ceiling on 35mpw!
As for workouts, it would be helpful if you said something about what you are doing now, but...
During your build-up, a weekly tempo or broken tempo (short rest) is good, 20-30 minutes at your half-marathon pace or a little quicker. Or things like 2x15 minutes, 3x2 miles, 5-6x1 mile etc. (If you haven't raced a half, do a projection with McMillan or another calculator/table. I am going to guess 6:05-6:15 pace would be right for you. But go slower if you aren't recovering well. Many people kill themselves on their tempos, and that's not the point.)
3-5k pace work should be a staple, increasing the intensity of the workout by adjusting interval length and recovery as the season progresses. Early in the season, do it as 600s, 800s, 1000s, whichever. Mix it up. Think of doing race distance or a bit longer at race pace. To start, something like 6-8x800 (2:00 rest) or 5-6x1000 (2:30 rest) could be fine, or 4-5x800 (2:30 rest) or 3-4x1000 (3:00 rest) at 3k pace. As you build fitness and get closer to your races, you should be able to do 5x1000 @5k with 1:30 or even just 1:00 rest, although that is pretty tough, near race effort. As a hard late season test, I like 2k/2k/1k or 3x1600 with 1:30-2:00 rest, 5k pace.
When you are sharpening, some mile-pace workouts like the classic 10x400 (1:00-1:30 rest) will be good to get you used to faster running. (Your 5k race shouldn't be the fastest you have run all season!) At your 18:00 goal ability, maybe 80 seconds each would be good, although that depends a bit on what your natural speed is like.
Good luck!