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Why You Feel Worse Right Before Your Best Race: The Science of Tapering
Tapering is the training phase where you reduce your volume in the final weeks before a race. Most runners feel terrible during it: heavier legs, phantom injuries, anxiety, the sudden urge to add one more long run "just to be safe." That feeling is not a warning sign. It's your body doing exactly what it's supposed to do.
What is tapering?
Tapering is the planned reduction of training load in the 2–3 weeks before a race. The goal isn't rest for the sake of rest but rather allowing your body to convert months of hard training into actual race-day performance. Think of it like a cake recipe: you've been adding all the ingredients to the mix (long runs, tempo sessions, and threshold work) and tapering is when you finally mix everything and bake the cake. What comes out of the oven is your race result.
The science is consistent on this. A landmark meta-analysis by Bosquet et al. (2007), reviewing 27 studies across competitive athletes, found that a 2-week taper where training volume is reduced by 41–60% while keeping intensity and frequency roughly stay the same, produces the most significant performance gains. A 2023 meta-analysis published in PLOS ONE confirmed those findings specifically for endurance athletes, showing significant improvements in time-trial performance following a properly executed taper.
The key word is volume. You cut the kilometres. You don't cut the speed work.
Why do you feel so bad during taper?
This is where most runners go wrong: they interpret the discomfort of tapering as a sign that something is wrong, and either panic or add kilometres back in. Or they think that adding a few more miles/ sessions will make them 'more ready' for race day. But it's actually the opposite... Here's what's really happening.
Your glycogen stores are filling up
During heavy training, your body is constantly drawing down energy reserves. When you reduce volume, those stores finally get to top up. Glycogen is stored alongside water, which means your muscles are literally taking on more fluid than usual. The result: heavier, slightly sluggish legs that feel nothing like the sharp legs you had three weeks ago.
This isn't fatigue. It's your fuel tank filling before race day. Research shows glycogen stores can increase by 20–40% above normal levels during a proper taper and for races lasting longer than 90 minutes, that difference is measurable in performance.
Your body starts doing all the repair work it's been delaying
During peak training weeks, your body is in a permanent state of managed stress. It prioritises keeping you going over deep recovery. When the training load drops, your immune system and repair processes essentially come back online fixing micro-damage in muscle fibres that accumulated over months.
That process produces real physical sensations: odd twinges, vague tightness in your Achilles or hip flexors, that knee that suddenly "feels weird." These are not new injuries. They are repair signals. The fact that you notice them now is because your brain is no longer flooded with training-related stimuli.
Your nervous system is recalibrating
This one doesn't get talked about enough. After weeks of high load, your nervous system adapts to constant demand. When that demand drops, there's a period of recalibration that feels unsettling: lower mood, restlessness, disrupted sleep.
Research shows cortisol (your primary stress hormone) drops during taper, while testosterone rises. That hormonal shift is anabolic meaning that it pushes your body into a building and recovery state. But it takes a few days before it feels like anything other than "off."
Your brain fills the silence with noise
Taper madness is real and documented. When you suddenly have two extra hours in your week and your legs feel strange, your brain needs something to do with the anxiety. It defaults to worst-case scenarios: you've lost fitness, you haven't done enough, your race is ruined.
None of this is true. Research is clear that measurable losses in aerobic capacity don't occur until after 2–3 weeks of complete training cessation not 2 weeks of reduced training.
How to actually taper (not just "run less")
There's a common mistake recreational runners make: they interpret tapering as running less and easier. That's not quite right. Cutting intensity during taper leads to flat legs on race day. Here's what the evidence actually supports.
Reduce volume, not intensity. Your long runs shorten significantly but keep some quality in the week. A short tempo effort or a few race-pace strides in the final week keeps your neuromuscular system sharp. Your muscles need to remember what race pace feels like.
2 weeks out. Your last long run should be roughly 12–14 days before race day. Week one of taper, drop volume by around 30–40%. Final week, drop to 50–60% of your normal weekly load. Keep at least one quality session (strides, short tempo) in week one.
3 weeks out. The accumulated fatigue from marathon training is deeper, so the body needs more time to process it. Your last long run (20–22km) should be 3 weeks out. Volume drops progressively from there, with quality maintained in the first two weeks.
A 2021 study by Smyth & Lawlor (University College Dublin) analysed taper patterns from 158,117 recreational runners using Strava data. Runners who followed a longer, disciplined taper consistently performed better on race day than those who maintained high volume until the end — regardless of overall training level.
Don't change anything else. Taper week is not the time to try a new pre-race meal, new shoes, new warm-up routine, or new sleep schedule. Everything that isn't part of your normal routine is a variable you don't need. Race day is for execution, not experimentation.
What about the mental side?
The psychological symptoms of taper are well-documented in sports science. A 2023 scoping review in Sports Medicine (Stone et al.) confirmed that athletes consistently report mood disturbances, increased somatic awareness, and performance anxiety during taper and that these symptoms have no predictive relationship with race outcome.
What that means in plain language: feeling terrible during taper tells you nothing about how race day will go. The correlation between taper discomfort and a bad race is essentially zero. In fact, the runners who feel the worst during taper are often the ones who trained hardest going in which is exactly where you want to be.
My advice: don't try to fix the discomfort. Expect it. Have a plan for what to do with the extra time and energy: logistics for race day, nutrition prep, mental rehearsal of your race or just catching up with friends and family that you maybe saw a bit less due to your trainings. The runners who struggle most during taper are the ones who weren't prepared for it to feel this way (and maybe they should also have an honest conversation with themselves why nt doing sports is affecting them so much).
The bottom line
Tapering is not a reward for months of hard work. It's the final, non-negotiable training block and skipping it or cutting it short is one of the most common ways recreational runners leave time on the table. The fitness you built doesn't disappear in two weeks of reduced running. It consolidates. Your muscles repair, your glycogen fills, your nervous system freshens up, and on race morning you get to express everything you actually worked for.
The discomfort you feel during taper? That's the process working.
The short version
- ✓Tapering means reducing volume by 41–60% in the 2–3 weeks before your race, while keeping intensity
- ✓Heavy legs during taper = glycogen loading. This is your body fuelling up, not falling apart
- ✓Phantom aches are your repair systems catching up, not new injuries
- ✓Nervous system recalibration takes a few days; the unsettled feeling is hormonal and temporary
- ✓Aerobic fitness doesn't drop in 2 weeks of reduced training and the science is clear on this
- ✓Taper anxiety has no relationship to race day performance. Expect it, don't act on it
Want a structured plan that builds your taper in from day one?
Inside the Run Smarter App, training plans for 5K through half marathon include a built-in taper phase so you don't have to figure out the final weeks on your own.
- Bosquet, L., Montpetit, J., Arvisais, D., & Mujika, I. (2007). Effects of tapering on performance: A meta-analysis. Medicine & Science in Sports & Exercise, 39(8), 1358–1367.
- Wang, Z., Wang, Y., Gao, W., & Zhong, Y. (2023). Effects of tapering on performance in endurance athletes: A systematic review and meta-analysis. PLOS ONE.
- Stone, M.J., Knight, C.J., Hall, R., et al. (2023). The psychology of athletic tapering in sport: A scoping review. Sports Medicine, 53(6), 777–801.
- Smyth, B. & Lawlor, A. (2021). Longer disciplined tapers improve marathon performance for recreational runners. Frontiers in Sports and Active Living.
- Mujika, I. & Padilla, S. (2003). Scientific bases for precompetition tapering strategies. Medicine & Science in Sports & Exercise, 35(7), 1182–1187.
