The Science Behind the Art of Marathon Taper

Like politics, it is both loved and hated; it is recognized as necessary for success; and it has its own fair share of controversy. It is known by marathoners around the world of every caliber, experience, and age. It is the taper.A chosen taper method may work wonderfully for one marathon, but leave the same runner feeling less than optimal for the next marathon. Because runners get older while at the same time they are gaining experience, because they are able run more miles while possibly becoming more injury prone, and because each marathon presents its own unique course and challenges, there simply cannot be a one size fits all taper strategy. It is for these reasons, that a running coach may approach the taper as if it were a work of art. However, understanding and applying the science behind the taper will help the coach prepare a masterpiece for the runner’s next marathon.

Quite simply, a taper is a reduction in training volume (and some would say intensity) in order to optimize race day performance. From a more scientific point of view, “Taper is a strategy typically implemented by athletes in the days and weeks leading up to a competition of emphasis. Defined by a systematic reduction of training load, taper yields physiological and psychological benefits that together improve performance by approximately 2–8%.” (1) For the typical four hour marathoner, that could mean crossing the finish line anywhere from 5 to 19 minutes sooner, making the taper very enticing to perfect.

One of the concerns of the taper, most often expressed by runners new to the marathon, is losing fitness during the taper. Joe Friel, coach, author, and co-founder of endurance training software TrainingPeaks, explains why this is an unfounded concern. “Fatigue changes more rapidly than fitness when you are resting. So while a pre-race taper will shed a lot of fatigue quickly, fitness will be lost very slowly. On race day you will feel as if you had gained fitness, even though that feeling is actually the result of having less fatigue. It doesn’t matter – you’ll be on form.” (2)

In order to have an even deeper understanding of the benefits of the taper, it’s important to take a brief look at what happens during marathon training in the weeks preceding the taper. A typical marathon training plan is approximately 16 weeks long. During that time, the runner’s mileage is increased on a weekly basis with cut back (reduced mileage) weeks built in periodically to prevent over training which can lead to injury. In a 2012 study published by the Journal of Exercise Science & Fitness it was found that even well rested runners with at least 16 years of endurance training showed signs of muscle damage 24 hours, 48 hours, and 72 hours following a 16 mile training run at submaximal pace. (3) This muscle damage was shown by markers known as CK (creatine kinanse), which is an enzyme that passes into the lymph system via interstitial fluid. The Muscular Dystrophy Association explains how increased CK levels in the blood signal muscle damage, “During the process of muscle degeneration, muscle cells break open and their contents find their way into the bloodstream. Because most of the CK in the body normally exists in muscle, a rise in the amount of CK in the blood indicates that muscle damage has occurred, or is occurring.” (4)

When one considers the fact that a marathon training plan likely includes tempo runs, speed intervals, and long training runs, often within the same week, complete muscle damage recovery is something that likely does not occur until well into the taper portion of marathon training. Interestingly, a runner cannot necessarily know when one has achieved complete recovery from muscle damage due to marathon training. One of the findings in the study with the 16 mile training run was that muscle soreness was not an indicator of muscle damage. Additionally, it was noted that CK values tend to not return to baseline levels until as many as 6 days after the long training run, with peak values ranging from 2-4 days after intense exercise. While the runners in the study experienced muscle damage lasting 3-6 days after the long run, not all runners (if any) experienced muscle soreness after the run.

In essence, we’ve built a case for including a taper near the end of training and shortly before the race. After 13-14 weeks of marathon training to improve speed and endurance, not only has muscle damage occurred, fatigue likely has settled in as well. In the next 2-3 weeks, the runner needs to experience muscle repair and increased muscular energy stores in order to realize the benefits of hours and miles of training runs. That’s where the taper comes in.

What happens during the taper to bring about positive results that could include up to an 8% improvement in performance? According to a 2010 study by the Human Performance Laboratory at Ball State University in Muncie, IN, one of the interesting outcomes of a three week taper for a group of collegiate cross country runners was the “enhanced single muscle fiber size and function that targeted MHC IIa muscle fibers.” (5) These are the fast twitch muscle fibers. They note that, “Although we do not know to what extent, it is reasonable to assume that a more powerful MHC IIa myocellular profile is beneficial for whole muscle and running performance.” This offers an explanation as to why even though the slow twitch muscle fibers (MHC I) experienced no change in “size and function, baseline gene expression, citrate synthase activity, or maximal and submaximal cardiovascular function” the runners in the study still experienced significant improvement in their performance. It also is important to note that although volume was reduce by 50% by the third and final week of taper, there was no change in the subjects’ aerobic profile (i.e. VO2max remained the same). This study did not address the topic of glycogen muscle stores; however, a study by B. Shepley, et al., The Physiological Effects of Taper on Highly Trained Athletes, confirms what coaches and runners seem to inherently know: muscle glycogen concentration (fuel stores) increases significantly after an appropriately executed taper (6).

Now that we have an understanding of the benefits of tapering for a marathon (improved muscle function and increased fuel stores), the next question likely is what strategies should a coach and runner implement for a successful taper? In the previously mentioned Shepley study, three different tapering strategies were studied were with highly trained middle distance athletes. These tapers were referred to as 1. High intensity, low volume, 2. Low intensity moderate volume taper, and 3. Rest-only taper). The table below gives a summary of how each taper strategy impacted the runner’s ability to perform on race day:

	HILV	LIMV	ROT
VO2 max	No change	No Change	No change
Time to fatigue	+ 22%	+ 6%	-3%
Citrate synthase	Increased significantly	Not noted	Decreased significantly
Muscle glycogen concentration	Increased significantly	Not noted	Increased significantly
Strength	Increased	Increased	Increased
Total Blood Volume	Increased significantly	Not noted	Decreased

Clearly, Shepley’s study indicates that a high intensity, low volume taper has the most positive outcomes. Most notably is the 22% increase in time to fatigue – an outcome any marathoner would be very happy to experience. Like the Shepley study, the Ball State University study that analyzed the taper of collegiate cross country runners, maintaining intensity in training while reducing volume played a key role in the successful taper. The area of training that had the most significant reduction in volume was the moderate intensity run workouts, while in comparison, the aerobic/recovery and high intensity workouts were decreased considerably less. This study noted, however, that increasing intensity could have the opposite effect of maintaining intensity. A similar group of collegiate cross country runners reduced their total training volume for 4 weeks, but increased the quantity of interval training. These runners had no significant improvement in race performance. They also experienced a decrement in MHC I fiber size and function along with no adaptations among the MHC IIa fibers. Intensity “should therefore be closely monitored to ensure that training conducted during taper allows adequate recovery to promote gains in myocellular power.” (7)

If reducing run volume is a key component to an effective taper, the natural question to come next is how much mileage should be cut? According to Alex Hutchinson, author of Endure, PhD in Physics, and researcher for US National Security Agency, states, “A meta-analysis of 27 different tapering studies concluded that the best results come from cutting mileage to 40 to 60 percent of your normal load. The higher your mileage, the more you’ll need to cut. In a multi week taper, cut your mileage progressively. For example, run 80 percent of your normal mileage in the first week, then 60 percent in the final week.” (8)

Next, it’s important to consider over what time period should this volume reduction take place? On one end of the taper time table is USATF Coach Greg McMillan of Mcmillanrunning.com. For the recreational runner, McMillan finds that two weeks is enough time to reap the benefits of a taper. “He says today\’s recreational runners simply don\’t need as much rest as those of 30 years ago. That\’s because they log 30- to 40-mile weeks instead of 70, making a heavy taper unnecessary. In addition, he says, ‘we understand the recovery cycle better.’ Today\’s training programs have rest and recovery built into them, so runners are less likely to be fatigued or over trained.” (9) McMillan recommends reducing mileage by only 10-20% in the first week of taper, then another 10-20% the week leading up to  the race (for a total reduction in volume of 20-40%). He also suggests that four days prior to the goal marathon, a runner do a workout that includes 4 X 3 minutes at 10K pace with 1 minute recoveries.

On the other hand, Hal Higdon, coach and author of Marathon: the Ultimate Training Guide, recommends a three week taper for his recreational runners and a two week taper for his experienced, competitive runners. (10)  Also unlike McMillan, Higdon recommends that marathon week contain very light training. Higdon recommends cutting 25% of your mileage the first week of the taper, then another 25% the second week of the taper. By marathon week, Higdon recommends minimal running up to approximately 9 miles total for the week, excluding race day. (11)

One of the most celebrated and accomplished U.S. marathon runners is Meb Keflezighi. In a Runner’s World interview shortly after his 2014 Boston Marathon win, Keflezighi shared that his taper didn’t begin until approximately 10 days before this race. Throughout his regular training, Meb does not keep track of weekly mileage. Instead, he follows a nine day training cycle which allows him more time for recovery between long and intense training sessions. Prior to his target race, “his last significant workout is a 5- or 6-mile tempo run with a week to go. ‘Then it’s just maintenance,’ he says. ‘The point is to get to the start line healthy.’” (12) It makes sense that a shorter than typical taper works for Meb. Throughout his running career he was known for his incredible focus on recovery and what has become known as prehab. Prehab is taking the time to prepare your body for your workout, then going through the process of recovering after your workout. In Meb’s words, “Strengthening, stretching, form drills, cross-training, and recovery practices are among the ways I implement the ‘prehab, not rehab’ principle.” (13) While most runners may view these as little things, Meb sees that they essential, and are “like compound interest, building to something big over time.” (14)

Ethiopian Kenenisa Bekele, the world’s second fastest marathoner, appears to place value on prehab, as well. In his 8 week training log leading up to his 2019 Berlin Marathon win in 2:01:41, Bekele scheduled 4-5 gym sessions each week, which were labeled as “general strength, corrective workout.” (15) His manager, Jos Hermens, shared with Amby Burfoot of  PodiumRunner.com that, “We have a very good physical therapist here who worked on a number of things with Kenenisa. He needed balance work, stability work, and chiropractic. We found that he was unbalanced at the hips, which gave him a leg-length discrepancy. That had to be fixed.’”(16) This attention to functional details may be a reason why Just 8 days before his near record setting marathon (just 2 seconds shy of the record set by his teammate Eliud Kipchoge), Bekele was able to safely complete a 32 kilometer run (10K at 5:54 pace, 20K at 4:58 pace, then 2K at an easy pace) early in the day, then later in the day ran a 10K (5:54 pace) followed by 5 X 2k at a bit slower than marathon race pace. Just four days before the Berlin race, Bekele’s workout included 12 X 2 minutes at race pace with 90 second recoveries. (17)

Few elite runners are as willing to share the specific details of their training, including the taper. For example, in an interview with Runners World, Galen Rupp, the current top U.S. Marathon runner, held back on revealing his weekly mileage leading into his 2018 Boston Marathon taper (a race he did not finish). He did share, however, that he “cuts his total by more than half in the two weeks preceding a marathon….Rupp keeps touching on speed every two to three days during his taper. And although the broad outlines of it are the same before each marathon—a sharp reduction in mileage for two weeks—he keeps it somewhat flexible. ‘It depends how I’ve been feeling the weeks leading up,’ he said. ‘It can never be this set routine.’” (18)

That is where a coach’s artistic ability plays such an important role in the taper. It’s clear by looking at the strategies of successful coaches, elite athletes and recreational athletes that no two tapers are exactly alike. Scientific study presents us with our options, and understanding those options are important. Without a doubt, though, the decisions on when and how to implement what we’ve learned through science are best determined by understanding the athlete.

Bibliography

1. Lunden, Nicholas; Hayes, Erick; Galpin, Andrew, et al. June, 2010. Myocellular basis for tapering in competitive distance runners. Journal of Applied Physiology. Retrieved May 26, 2020 from https://journals.physiology.org/doi/full/10.1152/japplphysiol.00045.2010    
2. Friel, Joe. The Triathlete’s Training Bible: The World Most Comprehensive Training Guide. 4^th Edition. Boulder: Velopress. 2016. Print. 37-38.
3. Quin, Timothy J. et al. The impact of a long training run on muscle damage and running economy in runners training for a marathon. Journal of Exercise Science & Fitness, volume 10, issue 2. December 2012. 101-106. Retrieved May 28, 2020. https://www.sciencedirect.com/science/article/pii/S1728869X12000354
4. MDA Staff. Muscular Dystrophy Association. Simply Stated: The Creatine Kinase Test. January 31, 2000. Retrieved May 26, 2020. https://www.mda.org/quest/article/simply-stated-the-creatine-kinase-test
5. Lunden, Nicholas; Hayes, Erick; Galpin, Andrew, et al. June, 2010. Myocellular basis for tapering in competitive distance runners. Journal of Applied Physiology. Retrieved May 28, 2020. https://journals.physiology.org/doi/full/10.1152/japplphysiol.00045.2010    
6. B. Shepley, et al. (Physiological Effects of Tapering in Highly Trained Athletes) 1992 Retrieved May 28, 2020. https://pubmed.ncbi.nlm.nih.gov/1559951/
7. Lunden, Nicholas; Hayes, Erick; Galpin, Andrew, et al. (June, 2010) Myocellular basis for tapering in competitive distance runners. Journal of Applied Physiology. Retrieved May 28, 2020. https://journals.physiology.org/doi/full/10.1152/japplphysiol.00045.2010    
8. Hutchinson, Alex. Try This Tactical Approach to Tapering. October 17, 2017. Retrieved May 28, 2020. https://www.runnersworld.com/training/a20862558/tactical-tapering/
9. Juhng, Lisa. Is Your Taper Too Long? September 19, 2007. Retrieved May 28, 2020. https://www.runnersworld.com/training/a20790014/find-out-if-youre-tapering-too-much-com/
10. Higdon, Hal. Marathon: The Ultimate Training Guide. 4^th Edition. 175
11. Higdon, Hal. 275-280.
12. Douglas, Scott. How Meb Keflezighi Trained to Win the Boston Marathon. May 2, 2014. Retrieved May 29, 2020.  https://www.runnersworld.com/races-places/a20852813/how-meb-keflezighi-trained-to-win-the-boston-marathon/
13. Keflezighi, Mebrahtom. 2015. Meb For Mortals: How to Run, Think, and Eat like a Champion Marathoner. Retrieved from https://play.google.com/books/reader?id=1_IIBwAAQBAJ&printsec=frontcover&output=reader&hl=en&pg=GBS.PT18.w.0.2.110
14. Keflezighi. Retrieved from https://play.google.com/books/reader?id=1_IIBwAAQBAJ&printsec=frontcover&output=reader&hl=en&pg=GBS.PT18.w.0.2.110
15. Sweat Elite. Kenenisa Bekele – Training Leading To Berlin Marathon 2019 (2:01:41) No Date. Retrieved May 29, 2020.  https://www.sweatelite.co/kenenisa-bekele-training-leading-to-berlin-marathon-2019-20141/
16. Burfoot, Amby. How Keninisa Bekele Trained for His Big Comeback I Berlin. October 4, 2019. Retrieved May 29, 2020. https://www.podiumrunner.com/training/how-kenenisa-bekele-trained-for-comeback/
17. Sweat Elite. Kenenisa Bekele – Training Leading To Berlin Marathon 2019 (2:01:41) No Date. Retrieved May 29, 2020.  https://www.sweatelite.co/kenenisa-bekele-training-leading-to-berlin-marathon-2019-20141/
18. Butler, Sarah Lorge. How the Pros Nail Their Marathon Tapers. April 14, 2018. Retrieved May 29, 2020.  https://www.runnersworld.com/training/a19818895/how-the-pros-nail-their-marathon-tapers/