Dialing it in: Taper training for the Boston Marathon || Interview with David Roche

Cruising country roads in Boulder County, with views of the Flatirons and snow-capped Indian Peaks.

Last month I posted a comprehensive interview with running coach extraordinaire David Roche. If you have not read it already, you should — it is valuable context for this interview, in addition to having standalone value.

Days after publishing it, I entered the last stage of my training for the Boston Marathon, which is April 17, a week from Monday. This is the infamous taper period, a delicate balancing act that hopefully leads to peak performance on race day.

To compliment the first interview, which focused mostly on the earlier training blocks, David agreed to a second interview focused on the taper.

Q || Four weeks prior to Boston, you scheduled the “KEY RUN OF THE WHOLE CYCLE” (all-caps included). It was 24 miles, with 16 at marathon pace. Why was this workout so important, and what was the reason for its timing?

I don’t give that workout to many runners. It gets back to the two most difficult elements of a road marathon for highly trained runners:

  • Absorbing sustained impact at high speeds for more than 2 hours; and,
  • Efficiently burning fat at fast paces.

Many bonks by elite runners can be attributed to either musculo-skeletal fatigue/breakdown or to depleted glycogen. This type of massive workout pushes back the bonk on race day. With a month between the key training run and the marathon, we have enough time to recover and fine-tune, instead of jumping right into the taper.

I was willing to give you this daunting workout because of your unique background: many miles on the legs over many years, with much faster runs in this training cycle than any other. So you are pushing your body in new ways related to speed over distance, but not intensity over distance.

Q || For a runner with less fitness or ability, would you still give them a similar workout (but shorter or slower, or both) at this point in the calendar?

This type of workout is a big risk if an athlete is doing lower mileage, since the overall stress will likely be too high relative to total training stress over the cycle. Instead, I like to focus most athletes on the main element that ruins marathons: the distance itself.

Marathon pace will usually feel pretty easy. In fact, it often feels easier for lower-volume runners that might be operating at a lower percent of lactate threshold. But eventually, around mile 16 or 18, that easy pace gets hard when their endurance runs out.

So I like most runners to complete a 24 miler, but at a relatively relaxed, easy/moderate pace. That provides a dose of mental confidence and physical resilience that could be what makes or breaks their race when they come up to the 10k-to-go wall. We get the intensity element through shorter, safer workouts.

Q || After that workout, my weekly mileage stayed about the same for two weeks, about 80 MPW. Only the last two weeks of the taper are lower, about 60 and 40, respectively, which is less of a reduction than I would have thought. You mentioned in a private exchange that, “The science of big cuts in mileage is really, really bad. We don’t need a new you on race day. We just need a fresh you.” Can you elaborate on that science, and explain what happens when runners cut back too much during their taper?

There are three component to a taper: feel, flow, and fitness.

Feel is what Steve Magness calls “muscle tension,” a concept describing tightness of muscle spindles. Too little tension from over-resting, and an athlete feels flat as a pancake, which is why you’ll often feel like shit the day after a rest day. Too tight from over-training, and an athlete won’t have as much energy return.

Maintaining adequate muscle tension is part of the reason why it’s important to keep general routines, including moderate mileage and solid workouts, even during race week.

Flow describes the mental state of feeling race-ready. That varies for different athletes — some need more rest to be mentally ready, some need less to avoid feeling unprepared. For an athlete like you (given your high-mileage training), a few miles do not tire you out, but failing to do them could make you have a self-doubt spiral on race week.

The final element is fitness, which considers all the other little things we are looking for in a taper, like muscle recovery and glycogen storage. There are some fascinating studies on tapering that paint an unclear picture. For example, rest may cause changes to the muscle fibers, and fast-twitch fibers can experience hypertrophy, among other things.

Stronger fast-twitch fibers are great for a speed athlete, like a swimmer in the Olympics doing a sharp taper. But for a marathon runner, that could be bad, and is likely one of a few reasons why elite endurance runners shouldn’t mimic tapers from more fast-twitch heavy sports.

On race day you need to be rested, but without having messed up the close-to-perfect balance you have earned during the training cycle. That is why I said in my initial email that we aren’t looking to create a new you on race day, just a recovered and ready you.

Q || I want to shift focus to workouts. The distance of the weekly long run and its marathon-pace component has decreased: from 24/16 (“the key workout”) to 16/0, 20/10, and 14/4. Meanwhile, the duration of the mid-week efforts has increased. Formerly, we did fartlek workouts (e.g. 20 x 2 min with 1 min easy in between). Now, the efforts are longer: this week, for example, I did a 10k at 10-mile race pace. Essentially, both weekly workouts are converging at 30-60 minutes. What does this accomplish in the final weeks before race day?

At the end of the training cycle, the time at marathon pace is mostly related to feel and musculo-skeletal adaptations. We want you to be cool as a cucumber at race effort and to burn a higher percentage of fat, which will be more sustainable on race day.

The workouts are transitioning from economy-oriented intervals that blend VO2 max (9-15 min pace) and Critical Velocity (35-40 min pace) to more pure lactate threshold (1 hour pace) tempos. In the first three months we taught your body to run fast. Now, your body must learn how to sustain fast paces.

The reason we are focusing on LT specifically (rather than faster 10k-pace tempos or slower marathon-pace tempos) is that marathon fitness is largely determined by the percent of lactate threshold you can maintain on race day. We have set that percentage with long, marathon-paced efforts during long runs. Now, we are trying to raise the denominator by getting just a bit speedier at LT.

In other words, the goal is to fine-tune your physiology. If the race itself is like a carnival game involving the physiological attributes we have honed in training, I want it to end with a big bell ringing and them giving you an oversized stuffed animal.

Q || You just partially answered this question, but I’d like it fully addressed. In the three weeks before race day, why did you not include any striders, which seemed so important in learning to “run fast” earlier in the training cycle?

The science on tapers in elite athletes is sparse, but some of the most interesting concepts stem from Magness again. Basically, it would take many pages to summarize the conflicting views, but one of the final elements in race performance is muscle-fiber recruitment, and the optimal recruitment pattern varies on the event.

For a marathon or ultra, we want to recruit slow-twitch, in order to maximize aerobic output for 2+ hours. By removing striders, we reinforce muscle-fiber recruitment patterns (and energy systems) we want to use on race day.

So for 3 or 4 months, the goal was to make fast feel slow. Now, the goal is to teach you to hold that slow-feeling fast for 150 minutes.

Q || Finally, how would you handle race day morning at a big race like Boston, when runners must be near the starting area well in advance? With that much butt-picking time, it seems like you could overdo stretching and warm-up drills, or mentally exhaust yourself with anxiety.

My advice is to stay warm and be chill. Bring more clothes than you think you’d ever need — it’s important to not let a single shiver into your spine to avoid wasting energy. If that means you’re shedding layers 3 hours before the race, that’s fine.

Otherwise, just get where you need to be, find a spot, and sit/lie down. Get up and walk a bit, but don’t run until 40 minutes before the race, when you just do 5-10 minutes of easy running before stripping off your clothes and doing a few strides (plus pooping one last time!).

Before the Olympic finals, Usain Bolt would famously nap in the locker room. Be like the Bolt — be chill, limit movement to walking around for a few minutes every half hour, and save your mental and physical energy for when it counts.

Take your running to the next level with David? It has worked for me!


  1. Rob W on April 8, 2017 at 7:21 am

    Great post! Got me excited for my Fall marathon.

    What is your goal time?

    Is there runner tracking available?

    Have a great run!

  2. Dave Gardner on April 8, 2017 at 10:08 am

    Andrew/Dave, I have immensely enjoyed watching your training cycle on Strava and in these interviews. Observing an excellent student/teacher relationship in action is a thing of beauty!

    Ill be watching you all the way to the finish on Patriots Day-

  3. Danny Caperton on April 8, 2017 at 2:13 pm

    Have a great race Andrew! I know about a dozen people running in Boston, but I’m most excited to see how your race shakes out. I’m excited for you!

  4. Jeff Boyer on April 8, 2017 at 2:24 pm

    Great explanation of the taper process! I’m running Boston for the first time so also appreciated the race morning tips.

  5. Doug K on April 8, 2017 at 9:06 pm

    thanks Andrew and Dave – I’ve been running/racing for over forty years and still learn things from Dave..

    ran Boston in 1991, was not in shape for a PR so ran an even split 2:50, had fun all the way – it’s a marvellous race and a peak experience in my running life.
    Yes, I took a nap while waiting for the start..

    Best of luck Andrew..

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