– The basics of the Yasso 800’s: 10 reps of 800 meters all as close to the same pace as possible. The average pace of the reps should correspond with your potential marathon time. For example, if you can consistently run the 800’s in 4:05, that indicates you can run the marathon in about 4 hours 5 minutes max. Some experienced marathoners find this estimate is fast by a few minutes, which is why I refer to the estimate as a max.
– A lot of what I say assumes you’re not a hardcore runner logging elite-like volume. When you’re pumping out 100+ miles a week, you probably already do speed workouts with volume like this all the time and can probably nail your 5K pace or better. The more volume you can run per week and/or the fewer marathons you’ve done, the more you should scale back the Yasso projection, e.g. if you run 100 miles a week and can run 800’s in 3:05, maybe estimate something closer to 3:20 for your marathon. Or if your 20 miler is the first time you’ve ever run 20+ miles, scale those 4:15 Yassos back to a 4:30 projection.
– Also, obviously, if you’re training for marathon, you should be logging more than 20-30 miles a week during training. Probably way more. 40-50 is probably the minimum if you don’t already do several marathons a year. I feel a lot of self doubt having run 30-50 per week, and many would say I’m in pretty good shape for Chicago in October (while many would say I’m not even close).
– As with any interval workout, you should not race these reps: Don’t do them hard. Don’t pick up the pace at the end of the rep. The rep should be steady wire to wire, and at the finish you could go another few miles at that pace if you had to. It’s supposed to be a barometer of your capabilities, and going closer to your max is not going to portray an accurate picture of those capabilities.
– According to most reliable pace charts (Daniels, McMillan, etc… don’t @ me, Pfitzinger-bros; his pace benchmarks are as faulty as his training methods)… you should be able to hit a desired Yasso goal at about your 10K pace or slower. If you’re giving more like an 8K or 5K effort to hit your pace on these reps, then not only is the workout inaccurate, but unless you run 100+ miles a week and do workouts like this all the time you probably won’t maintain the stamina to nail that pace consistently for all 10 reps.
– If your inter-rep recovery is supposed to be a jog instead of a full rest, a good barometer of whether or not you’re going too hard: Whether or not you can jog at a trot during the recovery interval. If you need to walk or stop, you went too fast.
If allowed a full rest, then a good barometer of whether you went out too hard is if you cross the line not feeling like you could have kept going another 800+ meters at your pace. You never want to race to the finish, or get to the line needing a total rest. Intervals should be run wire to wire at a pace you’d expect to maintain in a race, meaning you should cross the line able to keep running at that pace if you had to.
If at first you can jog your recoveries but then you have to walk or stop at later recovery intervals, it’s not only possible your intervals are too fast but also possible that your recovery jog was too fast. Recovery jogs should always be at a pace that would normally feel too slow. Most runners tend to run recovery intervals too fast (Hint: Your regular running pace is too fast). An analogy I find accurate is to observe a baseball hitter’s home run trot: That’s the effort you want to be putting into a recovery jog.
– Pay close attention to the results of reps 7, 8 and 9. In fact, you could average just those three reps and may get a more accurate Yasso 800 estimate than estimating the average of all reps. It’s your performance while tired in the later reps that’s going to paint the most accurate picture of your capability. However, bear in mind the tendency many have to do the final rep hard in an effort to finish strong. Rep 10 is probably going to look stronger than the other late reps. Pay closer attention to how reps 7, 8 and 9 look, when you’re tired but you’re not emptying the tank with a final flourish because you know you’ve got more reps to do.
– Another effective estimate method: Take the average of your 5 slowest reps. Few can fake 6-10 good, accurate reps.
– If the pace of your reps varies substantially (let’s say by more than 15 seconds between your fastest and slowest rep):
1. Most likely, you went out too hard. For most runners their reps in a speed workout typically vary like this: The first reps are very fast, and then later reps are much slower.
2. In some cases it happens when you start your reps super easy and then pick up the pace in later reps (like a negative split in a race). However, this indicates you didn’t warm up effectively beforehand.
3. If it consistently bounces back and forth by 12+ seconds per rep, you are either trying (at least on some reps) to hit a pace you’re not yet totally capable of running in a race, or you’re not taking full rest periods. If you’re in the middle of a Yasso workout and you see your times doing this, focus going forward on running a comfortably brisk pace that’s a tick slower than you want to run (whatever that means to you), and try to hit the same pace on the remaining reps.