This is why I still come to this site. Now my justification for saying that milers should be doing tempos and intervals of at least 600m each is that the complete runner is going to run a wide variety of workouts and paces. What is the best way to improve? If you do low mileage, add some mileage; if you don't do a long run, add a long run; if you don't do tempos, do some tempos; if you don't do speed (200-400), add some speedwork; if you don't do hills, add hills. The basic idea is that you can make greater improvements by adding a new element that covers one of your weaknesses. In this case, these guys, it seems to me, have plenty of speed for the sub-4 1500m. That is, they are not struggling all-out to go 64-5 for a 400m. They can run sub 60s in workouts frequently. Where they could add something in-season is in the area of tempos or much harder tempos and longer mile-3k pace work, at the very least. So, the occasional 600s in low 1:30s (eddy did a 1:27 recently, I think), 800s in low 2:10s, mile pace 1k's and maybe even 1200s. I'm not saying a lot of reps of this work, but they need some longer stuff to bridge the gap between the short repeats and the longer race. Then the 5k pace work at 1200-2k will build strength or aerobic power or efficiency or whatever term you like. In any case, take this example from Steve Scott's training in 1982, where he does a lot of 660s and 880s, hills, and hard longer runs, such as the 10 miler in under 52:
26 April, Monday: AM 5mi loop, a little
tired. PM warmed up with ASU,
ran 8mi. Felt like shit, feel like a cold is coming.
15mi
Tuesday: No AM run, felt bad. PM felt better.
2x660-550-495-440-395 all sub60
pace. Last 440 in 51.1 3mi warmup, 2mi cooldown.
8mi
Wednesday: AM no run. PM 10mi w/ Pete on Canal.
Weights.
Thursday: AM 5mi. PM Supposed to be social 10mi but
ran hard with Pete. Sub52min!
Friday: AM 5mi real easy. PM Felt bad first 4mi,
easy out, hard on return. 15mi.
Saturday: AM 4mi loop. PM Ran 9mi to Pete's house.
Very windy. Weights.
Sunday: South Mtn run w/ Pete. Good, a bit dry. Went
to ASU baseball game. 15mi
Week: 91mi
3 May, Monday: AM no run. PM Easy/good 10mi +
weights.
Tuesday: AM 5mi, felt real bad. PM 3x440 (58.4) w/
200j, 880w, 880 (1:54.5),
440w, 440 (52.4). Easy workout. 12mi
Wednesday: AM 5mi loop. PM 10mi on canal easy.
Thursday: AM 5mi PM 2x(2x440-660-440-8x220) workout
was great all times fast!
15mi
Friday: AM 5mi. PM 5mi at school. Drove to CA.
Weights.
Saturday: AM 10mi run PM 2mi, golf - shot a 92.
Sunday: 15mi run with John in the foothills.
Week: 85mi
10 May, Monday: Felt really bad. In LA for
promo work for Al Franken.
Stopped at Cal Poly for easy 5mi, felt terrible.
Tuesday: AM good 5mi run PM Slept all day. Cold,
windy, wet foothills run. 15mi
Wednesday: @ UCI. 2x440-880-440-6x220-3x440. Very
good workout. 57-58, 1:54-58,
29s, 55-58-52. Jogged 6mi after. 13mi.
Thursday: AM 5mi run PM Easy run. 15mi
Friday: AM no run. PM Good run + strides. 10mi
Saturday: AM 5mi easy. PM 5mi easy.
Sunday: Pepsi Mile. AM 3mi. PM Race went
well. 1200@3:00, 3:52.68. Paige
was good. Jogged 6mi after.
Week: 80mi
17 May, Monday: AM felt real bad on run.
Legs hurt from volleyball.
Smoggy. 10mi
Tuesday: AM 5mi hard PM 10mi real hard fartlek.
Great run, windy on return.
Wednesday: AM 5mi good pace PM 10mi good pace.
Weights.
Thursday: AM 5mi loop. Felt tired, sore. PM 10mi
real easy.
Friday: AM 5mi loop good pace. PM 3x(440-880-440)
220j, 440x b/sets. 58-1:56-58,
58-1:58-57, 58-1:57-55. Good workout, not real hard.
13mi
Saturday: Easy, moderate 10mi.
Sunday: AM Just 5mi.
Week: 85mi