You need to add some threshold, fartlek or hill work into your routine somewhere.
This is mine however times & distances vary:
Monday- x-train, 3 mile recovery run or rest day,
Tuesday- Threshold, 1 mile jog , 2x 8 mins @ 80-85% max, 1 mile jog
Wednesday- 6miles @60-65% with 15mins @70-75% mid run
Thursday- fartlek pyramid, 1 mile jog, 10 secs @90% of max, 2 min recovery jog, 20 secs@90% of max then 2 min recovery jog, 30 seconds @ 905 of max thhen 30, 20, 10 seconds with 2 mins recovery jog
Friday- Hill session. 3x 8 mins hill running @80-85% of max with 5 mins recovery between
Saturday- REST
Sunday -Long run 9 miles or 1hr15 @60-65% with 15 mins @70-75% mid run.
Hope this is of help to you.Some people will agerr with this some will not. Training depends on the amount of time you have available. I train every morning from 06.15am for up to 2 hours.