My suggestion for you is twofold:
1) Limit 5km paced reps to 6 minutes. If your reps take longer than that, it's likely you "race" during practice sessons rather than train during them. I thik 2km at 5km race-pace is appropriate for a 14 flat 5km runner (or under), but it's too long for a 20-flat runner. If I were coaching you, the normal 5km race reps would be 3-4 minutes in duration.
2) Ask yourself this: Am I able to race every weekend at 5km, if I want to, and run strongly?
If you can't, then you are training too hard. You should be able to recover by Wednesday, if you raced on Saturday, and then you can or should do a moderate workout on Wednesday before another Saturday 5km race.
If you cannot race on consecutive weekends at 5km, then you should tweak your hard sessions/tame them a bit.
Your mileage is at the upper limit. At 70-80 miles per week at your level is the top I would prescribe. That's a lot of time on your feet already! I suspect you would be able to handle 60-miles per week, every week of the year, and for 6-week periods of time you could extend the volume to the 70-80m range before tapering for a peak performance. It may be worth it to do that twice, maybe three times, per year.
I wish you well and keep enjoying what you are doing!
Here's my 2012 Fall racing schedule [5ks, and a couple of baby jogger 5ks where I pushed my 9 YO, 14k and half] and how quickly I was able to resume training and recover for races the following weekend.
: 36 miles
Tuesday: 8 miles 1:12:08 - 9:00 avg. pace - 3x1000m @ 7:15 pace w/3x600m recovery @ 7:44 pace = 3 continuous miles @ 7:23 pace + 2x200m hill sprints @ 5:45 pace. Wind began to kick up pretty good so I broke it off at 3 miles.
Wednesday: 4 miles 40:16 - 10:04 avg. pace - recovery on hilly trail
Thursday: 8 miles 1:13:15 - 9:01 avg. pace - 2x2:00 @ 6:56 pace w/2:00 jog + strides
Friday: 5 miles 44:30 - 8:53 avg. pace - 6x400m @ 1:41 - 1:48 w/400m jog recovery
Saturday: 11 miles including 14k race
]. I'm happy :>
Sunday: USRD - chillin'
: 79 miles
Tuesday: 10 miles 1:20:25 - 8:02 avg. pace - moderate. Wow, felt great!
So kool to be cruising along aerobically at this pace. Two of the last 4 miles were @ 7:42 pace.
Wednesday: 12 miles 1:41:24 - 8:27 avg. pace - easy A.M. / Another solid run.
Counted 188 steps per minute @ a relaxing 8:30 pace. / 4 miles @ 4.7 mph + 4x200m @ 9.0 mph
w/front / back hops recovery / XT reverse leg press 3 sets P.M.
Thursday: 8 miles 1:11:12 - 8:54 avg. pace - easy A.M. / 8 miles 1:11:29 - 8:55 avg. pace - easy P.M.
Friday: 8 miles 1:10:32 - 8:49 avg. pace - easy. Felt like a pig. Stopped in the FinishLine during my run and ordered another pair of the Lunar Montreals.
Saturday: 15 miles 2:04:56 - 8:19 avg. pace - 3x5k @ 7:31 avg. pace w/1000m recovery 23:21 / 23:19 / 23:32
Sunday: 4 miles 34:47 - 8:39 avg. pace - easy A.M. / 10 miles 1:27:40 - 8:46 avg. pace - easy P.M.
: 42 miles - Taper
Monday: SRD - legs feel like pistons - wanna run!!!
Tuesday: 6 miles 52:30 - 8:45 avg. pace - recovery + strides. Felt kinda sluggish but everytime I looked at my pace it was faster than expected - encouraging. The more I tried to slow down the quicker the pace. Figured out I'm in A corral.
Wednesday: 5 miles 43:01 - 8:36 avg. pace - 2x1000m @ 6:57 pace w/90 sec. recovery + strides. Feelin' good.
Thursday: 4 miles 34:44 - 8:41 avg. pace - recovery / easy + 2xstrides. Started blah, finished strong.
Friday: 4 miles 33:59 - 8:30 avg. pace - 2x2:00 @ 10k pace [6:55 pace] + stride. Best I've felt overall this week ~ legs were jumpin'!
Saturday: 6 miles 52:24 - 8:44 avg. pace - 6x400m @ 1:40-1:50 w/400m jog. Speed taper done.
Sunday: 17 miles Columbus Half Marathon
] - New Master PB
: 42 miles
Tuesday: 8 miles 1:10:28 - 8:48 avg. pace - easy. Felt like a pig out there. Still feeling my race.
Wednesday: 8 miles 1:07:55 - 8:29 avg. pace - easy.
Thursday: 10 miles 1:25:53 - 8:35 avg. pace - easy.
Friday: 5 miles 43:11 - 8:43 avg. pace - 2x2:00 @ 6:43 pace w/1:00 recovery jog + strides. Better.
Saturday: 6 miles 53:19 - 8:53 avg. pace - 5x400m @ 7:24 - 6:44 pace w/400m jog. Legs were on fire!
Sunday: 5 miles. baby jogger 5k
: 51 miles
Tuesday: 8 miles 4x4 minutes @ 9.0 mph w/90 second recovery then launched immediately into 200m @ 10.0-10.5 mph + 4x200m @ 11.0 mph w/600m recovery
/ XT [leg extensions / reverse leg press]
Wednesday: 5 miles 42:50 - 8:34 avg. pace - moderate. Kinda gassed from yesterday's speedwork.
Thursday: 10 miles 1:19:58 - 7:59 avg. pace - moderate.
Not sure what got into me but tomorrow better be an easy run!
Friday: 8 miles 1:09:49 - 8:43 avg. pace - easy
Saturday: 10 miles 1:27:48 - 8:46 avg. pace - 14x400m @ 1:38 [6:32 pace] w/75 sec. recovery jog.
Sunday: 10 miles 1:23:20 - 8:20 avg. pace - easy w/surges
: 50 miles
Tuesday: 10 miles 1:27:28 - 8:43 avg. pace - super easy.
Wednesday: 5 miles 2 sets 400m @ 9.0 mph / 800m @ 8.5 mph / 400m @ 9.0 mph continuous w/2:20 passive recovery
+ XT. Not feeling well [food poisoning
] entire workout kinda blew.
Thursday: 7 miles 1:00:05 - 8:35 avg. pace - easy. Almost feeling back to normal.Plenty of pep but not a lot of stamina.
Friday: 8 miles 1:12:42 - 9:05 avg. pace - weak.
Saturday: 6 miles including baby jogger 5k
] A.M. / 4 miles 34:25 - 8:36 avg. pace - easy P.M.
Sunday: 10 miles 1:28:40 - 8:52 avg. pace - easy
: 51 miles
Tuesday: Tuesday: 6 miles 2200m @ 9.0 mph & last 200m @ 10.3 mph. Passive recovery / jog + 2x200m @ 10.5 mph
TM + XT [butt kick / pawing / high knees]. 2000-3000m @ 6:40 - scheduled
3 miles 4.5 mph P.M. / 8 miles 1:05:35 - 8:12 avg. pace - easy P.M. Awesome 2nd run in the cool 40° air. Felt like I was flying while holding myself back!
Thursday: 4 miles 33:29 - 8:21 avg. pace - 2x2:00 @ 6:26 pace + 2xstrides. Meh.
Friday: 4 miles 33:48 - 8:27 avg. pace - 5x400m 1:40 - 1:48 w/400m recovery.
Saturday: 8 miles including 5k
] A.M. / 6 miles 55:42 - 9:17 avg. pace - recovery P.M. Legs were dead!
Sunday: 12 miles 1:48:31 - 9:02 avg. pace - very easy
: 56 miles
Tuesday: 7 miles 1:01:30 - 8:47 avg. pace - 3x1000m @ 6:57 pace w/60 second recovery jog + 3x200m hill sprints @ 5:29 pace.
Meh. Legs still feelin' my race.
Wednesday: 14 miles 2:02:17 - 8:44 avg. pace - general aerobic
Thursday: 10 miles 1:32:00 - 9:12 avg. pace - very easy.
Friday: 6 miles 2000m @ 9.0 mph w/1:20 recovery 3x1000m @ 9.0 mph w/1:15 recovery w/200m sprint @ 10.4 mph
+ XT leg extensions & reverse leg press, butt kicks & pawing.
Saturday: 8 miles 1:06:00 - 8:12 avg. pace - moderate.
Feeling good so I just went with it.
Sunday: 12 miles 1:51:00 - 9:14 avg. pace - general aerobic. Productive run, mapped out a new route for our 5k race.
: 60 miles
Tuesday: 7 miles 1:02:18 - 8:54 avg. pace 2000m @ 7:04 pace + 2x200m hill sprints.
Felt as if I was moving much faster than the watch proved!
Wednesday: 10 miles 1:31:50 - 9:11 avg. pace - recovery [pace-wise].
Thursday: 4 miles 38:31 - 9:37 avg. pace - 2x2:00 @ 6:46 pace + 3xstrides. Meh.
Friday: 5 miles 45:30 - 9:06 avg. pace - 5x400m @ 1:35 - 1:50 w/400m jog + 2xstrides @ 5:06 pace. Moocho better than yesterday. Jingle Bell 5k tomorrow.
Saturday: 7 miles 1:02:23 - 8:47 avg. pace - includes 5k
] A.M. / 11 miles 1:42:18 - 9:18 avg. pace - easy P.M.
Sunday: 10 miles 1:35:25 - 9:32 avg. pace - easy A.M. / 6 miles 54:30 - 9:05 avg. pace - easy P.M.
: 70 miles ***** BEGIN OFF SEASON XT *****
Tuesday: 10 miles 1:31:09 - 9:06 avg. pace - easy
Wednesday: 8 miles 1:05:40 - 8:12 avg. pace - moderate A.M. Couple of sub-7:30 miles feelin' good.
/ 2 miles + strides 9.0 - 10.0 mph / XT P.M. reverse leg press 3x110 lbs / theroband high knees / butt kicks / recumbent bike - 10:00 lvl 10 / form drills
Thursday: 10 miles 1:22:00 - 8:12 avg. pace - easy.
The XT yesterday seemed to have a positive effect on my stride length.
Friday: 14 miles 2:05:47 - 8:59 avg. pace - general aerobic
Saturday: 10 miles 1:35:48 - 9:34 avg. pace - recovery [pace] A.M. / 6 miles 52:30 - 8:45 avg. pace - easy P.M.
Sunday: 10 miles 1:33:50 - 9:23 avg. pace - easy
... And back in the Fall of 2009 I ran this 5k [to support a co-worker's XC team] after running 26 miles the previous day. Obviously not a goal race or a recommended taper but ironically this 5k was only 10 seconds slower
than the fastest 5k I ran that year [a couple of weeks later]. My focus that Fall was on the marathon, not the 5k.
Week 47: 94
Tuesday: 8 miles
Wednesday: 10 miles A.M. / 8 miles P.M.
Thursday: 6 miles 6xstrides 9.5-11.6 mph TM
Friday: 14 miles A.M. / 6 miles 4xstrides 9.5-11 mph A.M. TM / 6 miles P.M. TM
Saturday: 8 miles 5k
] A.M. / 10 miles P.M. TM
Sunday: 10 miles A.M. / 8 miles fartlek P.M.