My favorite season of training was with a coach who posts here occasionally, sisyphus. (It was only one season because I am injury prone and am not running at the moment - that's another story). Our partnership began while I was injured and we spent the whole year working around the injury while getting me back in shape. I enjoyed the training because it was different than anything I'd done before but I still got very fit. Here is a snapshot of the progression of quality work not including all the easy mileage and strides:
8/1 - 3 mile tempo at 6:19 pace
8/11 - 7.5 miles at 8:00 pace
8/15 - 2 miles at 6:20 pace
8/16 - 8 miles at 7:30 pace
8/18 - 10 miles at 7:40 pace
8/22 - 3 miles at 6:20 pace
8/25 - 10 miles at 7:40 pace
8/27 - 1.5 miles at 6:40 pace + 10x30 sec on/30 sec off with on's at 5 min pace
8/29 - 2x2 miles at 6:18 pace with 10 min jog in between
8/31 - 5x1 min on/1 min off at 5 min pace
*****9/3 - 5k in 16:48 (5:24 pace)
9/5 - 8 miles at 7:40 pace
9/8 - 10 miles at 7:40 pace
9/10 - 8x1 min on/1 min off at 5:20 pace
9/12 - 5 mile tempo at 6:00 pace
9/15 - 11 miles at 7:15 pace
9/19 - 3 mile tempo at 6:00 pace + 10x30 sec on/30 sec off with on's at 5 min pace
9/22 - 3 mile tempo at 6:00 pace + 10x30 sec on/30 sec off with on's at 5 min pace
9/25 - 15 min fartlek going easy-medium-hard every 30 seconds
9/28 - 4 mile tempo at 5:50 pace
10/3 - 10k cutdown from 7:00 pace to 5:45 pace
10/6 - 2 x 1 mile in 5:30 with 30 min run in between
10/9 - 6 miles at 6:40 pace
10/15 - 10x1 min on/1 min off with on's at 5 min pace
10/18 - 5x800 averaging 2:38 with 200 jog averaging 57
*****10/21 - Hilly 5k race in 16:52 (5:25 pace)
10/25 - 5 mile tempo at 5:55 pace
10/27 - 4 miles in 24:00, alternating 200's in 39 & 51
10/28 - 10.5 miles at 7:40 pace
11/3 - 2.5 mile time trial with hard final 800. 3200 at 5:30 pace then 800 in 2:14.
11/4 - 10.5 miles at 7:40 pace
11/7 - 8x400 with 200 recovery except the last rep is a 600 where the final 200 you kick for home. 400's averaged 77, 200's averaged 50. Final 200 in 32.
11/10 - 6 mile tempo at 6:00 pace
11/13 - 3 mile tempo where you do a fast stride-out every 800 meters. Averaged out to 5:50 pace.
11/15 - 6 mile tempo at 5:50 pace
11/17 - 12x400 with 1 min standing rest. First 8 averaged 72. Last 4 averaged 66.
11/18 - 10.5 miles at 7:40 pace
*****11/22 - 5k race in 16:04 (5:10 pace)
11/24 - 11 miles at 7:15 pace
11/27 - 3.5 miles at 5:45 pace
11/29 - 3x1600 with 400 jog. On each rep 5:20 pace through 1200 meters, then last lap in 75. Averaged 5:15's.
*****12/2 - 3.5 mile race at 5:14 pace
12/4 - 5 mile subtempo at 6:00 pace
12/7 - 5 mile subtempo at 6:05 pace
12/9 - 11.5 miles at 7:50 pace
12/12 - 60 min run including 6 hill bursts of 25-40 seconds
12/14 - 60 min run including 2x8x20 second hill bursts
12/16 - 12 miles at 7:30 pace
12/18 - 6 mile subtempo at 6:00 pace
12/22 - 3 mile subtempo at 6:00 pace + 4x400 in 67 with 1 min standing rest
12/23 - 11 miles at 7:15 pace
12/25 - 6 mile subtempo at 6:10 pace
12/26 - 2x1600 in 5:00, then 2x800 in 2:21. 800 jog after 1600’s, 400 jog after 800’s.
12/28 - 6 mile subtempo at 6:10 pace
12/29 - 4x1000 at 5:32 pace with 200 recovery in 51 + 12x200 in 32 with 2 min walking between
12/30 - 11 miles at 8:10 pace
1/2 - 5 x 3 min on/2 min off. On’s at 5:20 pace + 10x30 sec on/30 sec off with on's at 5 min pace
*****1/5 - 1 mile race in 4:24
This only takes us from my first fall 5k to my first indoor track race. There were other fun workouts and races that year, and I eventually ran 15:27 for 5k in March, 1:55 for 800 in March, and 3:58 for 1500 in June. But I think my main point in posting this was that you can get good results, even at the middle distances, without killing yourself with workouts.