In you opinion, which is a more effective workout: progression or fartlek?

Tempos, progressions, and fartleks/intervals all serve a similar enough purpose in base training - i.e. getting in some high-end aerobic running - that you probably don't need to stress about it too much. I would advocate a mix, since they do each have some advantages. Tempos work on maintaining focus, progressions allow you to hit some faster-than-tempo running while simulating (at least for me) the feel of a race a little more accurately, and fartleks again get allow for some quicker turnover.

I also really like doing some faster running in my long run occasionally. For what it's worth, here's my favorite two-week base cycle.

M: easy/normal

T: faster - tempo, progression, or fartlek

W: easy, longish

Th: easy/normal

F: easy + short fast efforts (hill sprints or relaxed 200s)

S: long, easy pace

Su: easy

M: easy/normal

T: faster - tempo, progression, or fartlek

W: easy/normal

Th: easy, longish

F: easy/normal

S: long run w/ tempo, progression, or fartlek

Su: easy

So every two weeks you've got three faster runs - one tempo (20-30 mins or 2-3x10-15 at 1 hour race pace), one progression (20 mins easy, 20 mins moderate, 20 mins moderate/hard, all by feel), and one fartlek (I usually keep these to 2-4 minute reps with 1:1 steady recovery to keep pace in the 5k/10k range). One short fast session (8-10x200 at mile pace with plenty of rest, or 6-8 hill sprints), then hit strides on 1-2 easy days per week.

They key for me has always been to put relatively little emphasis on the faster days - it's a stupid thing but thinking of them as "faster days" rather than "workouts" helps me keep things in check. "Workouts" are for in-season; during base, you're just trying to "stay in touch" with your speed while building your strength. In the spirit of Summer of Malmo, those easy/normal days aren't just for farting around the neighborhood, they're actual runs. The workouts should be mellow enough that you don't need more than one true easy day per week.

tl;dr: don't worry, do some faster running, get in good mileage.

Excellent response, thank you.

To clarify: when you say something like "Wednesday, easy/normal" are saying this as a double or just emphasizing that this is a steady state effort? I also notice that in this cycle you utilize a long run/tempo/fartlek blend thing. Could this look something like 15 mi, 10 @ MP or 80 minutes, normal first 40 minutes, then 1 min on 1 min off for the last 40? And just shake it up every week?

There is also a 3 day stretch of easy/steady states. I know you should not be hammering in base phase months before your championship race but it seems like there is a definite lack of quality here.

Just trying to understand all of the finer points. I appreciate the lengthy response.

Do both.

Perhaps consider a 10 day cycle instead of a 7 day cycle if it's possible for you. I can understand what you mean about progression runs getting wrecked with lots of hills involved, but they're part of the formula the success too. If you can't do them routinely then do them occasionally but make sure you still attempt to do them, so lets say you're running 8 miles. Run your route hilly side first very easy for tje first 3 miles, start progressing to whatever your desired pace is down the last 5 miles. Or just find a 1 mile loop that mostly flat and just run that loop 8 times in a row. You gotta do what you gotta do. I sometimes run a one mile right near my house and my neighbors probably think I'm crazy for running in the same direction same pattern for an hour straight.

As far as fartleks go, take advantage of the hills with that mix it up. Run hard the up hills jog the down hills, or reverse it jog up hill hit the down hills or, run hard per hill recover until the next one and repeat. The whole 4 on, 2 off is a structured type of fartlek but take the fun out of it since it's entirely scheduled and not random, but that's just my opinion about fartleks.

Keep doing your strides on easy days that you feel pretty good after a run. I wouldn't race them or force them. They should be smoothed and controlled with a large focus on form and turnover. Other than that I think your plan is pretty solid. Just don't race your fartlek workouts or all out sprint your strides. The purpose of base building is to develop and improve your aerobic system and prepare you for track workouts and track races. So make sure you take your easy days easy. Good luck to you.

I didn't specifically mean doubles, but I do like and recommend doubling. By easy/normal I basically mean start out easy, if you're feeling beat keep it easy, but don't force yourself to shuffle too slowly if you feel good. I like having 2-3 easy/normal days in a row during base because I can beef up one or more of them by going longer and/or faster, or doing good strides, without the mental pressure of having a workout penciled in. If you haven't already, search the boards for Summer of Malmo - I'm largely paraphrasing Malmo here.

For the faster long runs, I basically just do a moderate faster session in the second half of the run. 6-7 miles easy, 4-6 building to a strong steady pace, and a mile easy is my favorite. Or 4-5 easy, 3x10min tempo with 10 min steady in between, and 2 miles easy home. Again, the exact structure doesn't matter as much as just getting in some strong (but not straining) running over the course of a fairly long day on your feet.