If running a minimum of 13 miles (20K) on your long run day. Is speed work OK the day after? Speed work combined/broken up over 6 miles (9.5K) and then building to 12 miles (19K). Good chance of injury or great for building a headache? I’m hoping there is some benefits. Let me have it!
Well… 3 types of training stresses.
Frequency
Volume
Intensity
Unless you have a huge mileage base where 75+ miles a week is normal… you are mixing two training stresses back to back in a high impact sport.
You may be able to get away with it a couple times… but I would expect injury to happen at some point.
I would think you would get more out of it if you did your long run, then 1-2 easy days before speedwork… not to mention the quality of your speedwork following a long run day may not be as beneficial either.
Just my approach.
YMMV, but I’d end up:
- Doing a crappy speedwork session
- Hurt
.
Great, quality may reflect times in this case. I was off for sure. Not by much however expectations would have to be dialed back. Who said triathletes were smart? Thanks again. No injuries please 
I had good success doing speedwork during the long run. When training for HIMs, that meant tempo. There are many ways you can do this, but some examples would be, for a 13 mile run:
20 minutes easy
20 minutes E pace
15 minutes tempo
3 minutes easy
15 minutes tempo
3 minutes easy
10 minutes tempo
5 minutes easy
or:
30 minutes easy
start at E pace, and gradually accelerate for the rest of the run until finish with last 10 minutes at tempo
If you aren’t sure what your E or tempo pace is, put a recent race result into:
http://www.runbayou.com/jackd.htm
The day after, you’d want to plan a rest or recovery day.
This helps you keep an eye on the clock for sure. I tend to push from time to time with no elegance. It’s more when I feel like it. Your science seems to work? I will try this over 90 minutes and see how I feel. I hope it hurts, sounds like it will. Cheers.
If you do it right, it shouldn’t hurt all that much…tempo pace for 30-40 minutes shouldn’t wreck you. The recovery from these runs ought not to be much different then it would be from your long run at your normal pace.
If you’re body is strong enough, yes. Just look at the workout Rupp did immediately after setting the two mile record (5x 1 mile around 4:20 with the last at 4:01). However, he is not only elite but a beast of an athlete. If you think you can handle two hard running days in a row, I would recommend doing the speedwork first. I like the idea of doing a long run on already fatigued legs for those who are well trained enough, as I feel it allows one to get more benefit out of the long run without having to make it insanely long. However, doing speedwork immediately after a long run would just compromise the point of the speedwork session by limiting the intensity that can be done.
Finally, the only reason I can see to chance doing two hard running sessions on back to back days is if one is a highly trained athlete looking for that additional stimulus to make gains because you have done everything else and it is no longer enough.
Additional: combining a shorter long run with tempo intervals is a great move when the long run becomes easy and you no longer want to add distance. Add some extra recovery time tho the first time you attempt it.
What are you trying to accomplish with this regimen? If you can recover from your long run (12-24 h) then speed work is fine, but generally that’s a bit tough to do. Remember that each workout sets up the next. It doesn’t seem like this regimen necessarily sets up an injury as its just likely to be suboptimal. But maybe that’s how your schedule works and you have to live with it.
I’m no coach and this advice is probably worth what you paid for it. G’luck! -j