How Tapering Helps You Perform at Your Best
Kovács Ferenc Soma, Hungarian national record holder in middle-distance running
Every runner understands the simple physiological principle that if you ease off your training in the final days before a race, you can arrive at the starting line rested and “hungry” to run. In the world of sports, this is known as tapering. But is tapering merely based on the experience and observations of athletes and coaches, or is it actually supported by scientific evidence? That is the question we will explore in this article.
Tapering is the process of deliberately reducing training load so that the body can make the most effective use of the work completed during the peak training period. And all of this happens without losing the endurance adaptations we have built. While middle- and long-distance running is fundamentally about consistently completing high-quality and appropriate amounts of training week after week, on race day, freshness can be just as important as physical fitness when it comes to achieving the result you have been working toward. Put simply: tapering helps ensure that you are not only in good shape, but that you are actually able to express that fitness on race day.
The logic behind tapering is relatively simple. Training simultaneously creates positive adaptations and negative fatigue. During periods of high training load, the cardiovascular system becomes stronger, muscle metabolism improves, and the body becomes more capable of handling physical stress. At the same time, however, neuromuscular, hormonal, and mental fatigue accumulates. The goal of tapering is to remove as much of that fatigue as possible while preserving the adaptations created by training. According to the classic review by Mujika and Padilla, the purpose of tapering is precisely to minimize accumulated fatigue without compromising the training adaptations acquired beforehand. They found that performance improvements are typically in the range of a few percent. That may sound small at first, but over a 10K, half marathon, or marathon, even a few percent can translate into a significant difference in finishing time.
In a 2023 meta-analysis covering 14 studies, Zhiqiang Wang and colleagues specifically examined how endurance athletes respond to tapering. The results may initially seem surprising: tapering did not significantly improve either maximal oxygen uptake, or VO₂max, or running economy. However, athletes achieved faster time-trial performances and were able to sustain exercise for longer before exhaustion. In other words, tapering does not suddenly give a runner a “bigger engine.” It is more like finally being able to use the same engine without the handbrake partially engaged.
Perhaps the most practically important finding of the meta-analysis was that effective tapering does not mean complete rest. According to the researchers, an effective strategy for endurance athletes appears to be one in which total training volume is gradually reduced by 41–60%, while intensity and training frequency are largely maintained. The tapering period generally lasts no more than 21 days, while periods of 8–14 days appear particularly effective for running and cycling.
In practice, this means you do not necessarily need to eliminate every faster session during the final period before a race. In fact, one common mistake is for a runner to suddenly do nothing but easy jogging and then wonder why race pace feels awkward and unfamiliar on race day. Tapering is not about being lazy; it is about precisely reducing training load. For example, a previous 6 × 1000 m workout might become 4 × 800 m, with longer recoveries. The length of the long run can be reduced, but the legs should still remember the rhythm at which you want to race. The main rule is simple: reduce the volume, not the sharpness.
Previous studies involving runners support this approach as well. As early as 1994, Houmard and colleagues demonstrated that a seven-day taper improved 5K time-trial performance in runners. In the tapering group, training volume was significantly reduced while high-intensity intervals were maintained. The runners improved their 5K times by approximately 3%, while the control group did not experience a similar change.
Tapering is not only relevant to elite or highly trained athletes. A 2021 study by Smyth and Lawlor analyzed the training data of more than 158,000 recreational marathon runners and found that disciplined, consistently decreasing tapering was associated with better marathon performance. Runners who followed a strict three-week taper achieved a median improvement of 5 minutes and 32 seconds, or 2.6%, compared with those who used minimal tapering. It is important to note that this was an observational study, so it does not establish a cause-and-effect relationship that necessarily applies to every runner. Nevertheless, the enormous sample size provides strong evidence that deliberately structuring the final weeks before a race can matter even at the recreational level.
The biggest enemy of tapering is panic.
Many runners start feeling during the final two weeks before a race that they are “not ready yet,” that they “need another long run,” that they “should do one more hard interval session,” or that they might somehow “lose their fitness.”
But by this point, the goal is no longer to gain fitness. It is to reveal the fitness you have already built.
You cannot make up missed training during the final week. A hard workout performed too late can do far more harm than good.
This is where a system like Polar can become particularly useful. Tapering is not purely a matter of how you feel; it is also a measurable process. Polar Training Load Pro, for example, separates Cardio Load, Muscle Load, and Perceived Load. This means it does not simply look at how much you trained, but also how the workout affected your cardiovascular system, your muscles and musculoskeletal system, and how difficult the session felt subjectively.
Strain reflects your training load over the previous seven days, while Tolerance estimates your ability to handle training based on the previous 28 days. Together, these metrics can make it easier to see whether your current fatigue is actually decreasing during the taper.
Polar Nightly Recharge can also provide useful feedback during this period. The feature monitors sleep quality and how well your autonomic nervous system recovered overnight, using factors including heart rate, heart rate variability, and breathing rate.
During the final days before a race, the goal is not for every metric to look “perfect.” Rather, it is to understand how your body is responding to the reduced training load, whether recovery is improving, and whether you are introducing unnecessary stress during the final days before competition.
Good tapering, therefore, is not simply a period of doing nothing. It is more like gradually removing the layers of fatigue that have accumulated on top of your fitness throughout a long training block.
The work is already inside you.
The question is how much of it you will be able to access when you stand on the starting line.
That is exactly what tapering helps with: it does not magically make you faster. It allows you to run closer to the level that the work of the previous weeks and months has actually prepared you to achieve.