"I run 4:21 1500 and 16:29 5k and 34:40 10k." These times indicate more speed than endurance. If we take you at your word that you have have no speed, that means your training is biased too much to training speed.
Like fff says, you need to replace one hard workout with a semihard 6-8 miles. In threads like this, I usually bring back an old post to illustrate the potential of the semihard 7 mile run.
RE: training for 1600-5k on minimal miles 6/7/2005 7:52AM - in reply to milt Reply | Return to Index | Report Post
...If you're like me, you may find out that you prefer this type of training to your previous methods. I have been following the same basic schedule for three years now:
M-50 minutes with 7 miles @ aerobic threshold (5:45 pace)
T-50 easy plus striders
W-50 minutes with 3 x 1 mile at 12k pace (90 second rest)
R-50 minutes easy plus striders
F-50 minutes easy plus striders
St-2 hours medium with striders
Sn-50 minutes easy plus striders
On this training, I have run 15:12 5k, 31:30 10k, and a 2:28 marathon---not PRs, but within 2.5%. That is, I'm training at 50% of my former training mileage, but racing at 97.5% of my personal bests. I actually like running again too....