The taper is the part of the training block that most amateur athletes understand the least and trust the least. After months of building — chasing weekly TSS targets, grinding long runs, suffering through intervals — you're suddenly asked to do less, to rest, to watch your training feel easier and your legs feel heavier by the day. For many athletes it feels like the opposite of what you should be doing in the most important two weeks of the whole year.
But the taper is not a break from training. It's the final, specific adaptation phase of a periodized plan — the one where months of accumulated fatigue finally lift off the system and expose the fitness underneath. Done well, the taper is the reason an athlete who has been running 4:45/km in training suddenly runs 4:25/km on race day without it feeling hard. Done badly, the taper is the reason a well-trained athlete lines up flat, sluggish, and 3% off form on the one day it matters. This guide is the practical version of how to actually do it.
What does a taper actually do to your body?
At the end of a long training block, your body is in a specific state: fit but tired. Your chronic training load (CTL) has climbed steadily, your base fitness is the best it's been all year, and your accumulated fatigue (ATL) is high because of the hard work you've been putting in. Your training stress balance (TSB) — fitness minus fatigue — is negative. You are strong, and you are also buried.
The job of a taper is to let the fatigue dissipate much faster than the fitness decays. The physiological reason this works is that fatigue and fitness have different timescales. Fatigue responds quickly to reduced load and mostly clears in 7 to 14 days. Fitness responds slowly to reduced load and only starts to detectably drop after about 3 weeks. Cut training volume for 2 weeks and your fatigue drops sharply while your fitness barely moves — the difference is your race-day freshness.
Behind the scenes, several things happen. Muscle glycogen stores refill. Metabolic enzymes recover. Immune function rebounds. Hormonal markers of recovery (testosterone/cortisol ratio, growth hormone) improve. Neural drive — your ability to recruit motor units quickly and forcefully — actually increases during a well-executed taper. The end result: a body that is as fit as it was at peak training, but now able to access that fitness without a fatigue tax.
How long should a taper be? (Taper length by race distance)
The right taper length depends on the distance of the race and how much cumulative fatigue you've built up. Broadly, longer and harder events need longer tapers because they demand a lower fatigue state on race day and because the training blocks leading into them are heavier. The table below is the practical reference for most amateur athletes.
| Race | Taper length | Peak week volume → race week | Notes |
|---|---|---|---|
| 5K / 10K | 5–10 days | ~100% → ~60% | Too much taper costs sharpness |
| Half marathon | 10–14 days | ~100% → ~55% | Standard mid-distance pattern |
| Olympic triathlon | 10–14 days | ~100% → ~55% | Scaled across three disciplines |
| Full marathon | 2 weeks (3 for high-load) | ~100% → ~50% | Classic marathon pattern |
| 70.3 / half Ironman | 2 weeks | ~100% → ~50% | Light swim-bike-run sessions in race week |
| Full Ironman | 2–3 weeks | ~100% → ~40–50% | 10-day taper is too short for almost anyone |
| Ultra (50K–100mi) | 2–3 weeks | ~100% → ~40–50% | Same logic as Ironman |
Individual variation matters. Athletes with very high weekly training loads often need longer tapers than the textbook suggests. Athletes who train less need shorter ones. Arrive at the start with TSB between +10 and +25 (see TSS, CTL, ATL, TSB).
What should you cut, and what should you keep?
The single most important rule in tapering is: cut volume, keep intensity. This is the one finding that cuts through almost all the confusion around what a taper should look like. Multiple meta-analyses of taper protocols consistently show that the biggest performance gains come from reducing total training volume by 40 to 60% while maintaining training intensity and frequency. Athletes who reduce intensity along with volume show smaller gains or even detraining.
In practice, this means your hard intervals stay in the plan — shorter, fewer, but still at race-pace or faster. Your easy runs and long sessions get shorter and more moderate. Your training frequency stays roughly the same so your body keeps its rhythm.
- Volume — reduce by 40–60% across the taper weeks. Week −2 might be 70% of peak volume, week −1 might be 50%.
- Intensity — maintain. A short set of race-pace intervals is the sharpest tool you have in taper week.
- Frequency — maintain roughly. Don't suddenly drop from six sessions a week to three. Keep the rhythm.
- Duration of individual sessions — reduce moderately. Long runs shrink. Long rides shrink. Interval sessions lose a set or two but not the quality.
- Strength training — phase out or drop to maintenance. Heavy lifting in race week is not the moment to chase new PRs.
What does race week look like, session by session?
Race week is the final dial-in. It should never introduce anything new — no new workouts, no new shoes, no new foods, no new gear. Its job is simply to arrive at the start line fresh, sharp, and confident.
A typical marathon race week might look like: Monday easy 40 min, Tuesday short intervals at race pace (e.g. 5 × 2 min at marathon pace), Wednesday rest or easy 30 min, Thursday short tempo with a few race-pace pickups, Friday rest, Saturday short shakeout 20 min with a few strides, Sunday race. Volume is low, intensity touches race pace, frequency is maintained, nothing is left to chance.
An Ironman race week is similar but scaled: most athletes hold light swim-bike-run sessions through the week, each short, each with a brief burst at race intensity, and the final two days before the race are very light or full rest.
How should you eat and sleep during the taper?
This is the other side of the taper that athletes often get wrong. The default assumption is that because you're training less, you should eat less. That assumption is the fastest way to arrive at the start line with depleted glycogen, poor hormonal balance, and a sluggish body.
The correct framing: during taper, total training load drops but your body's recovery and repair processes are working overtime. Many athletes who feel 'flat' on race morning are simply under-fed during taper week. Eat to support recovery and refill glycogen. In the final 2 to 3 days before a long race, carbohydrate intake should go up, not down. The classic recommendation of 8 to 12 grams of carbs per kilogram of body weight per day in the 48 hours before a marathon is well supported by research and is the reason carb loading remains a staple of endurance racing.
Sleep is the other leverage point and it's free. Multiple studies show that athletes who bank extra sleep — even 60 to 90 extra minutes per night — across the final week before a race report better performance and subjective energy than those who maintain their baseline sleep. Sleep the Saturday night two nights before the race is actually more important than the night before the race itself (pre-race nerves often make the final night poor, but that's normal and rarely costs much performance if the prior nights were solid). For the hour-by-hour race-week routine, see the final 24 hours guide.
What are the most common taper mistakes?
Five mistakes catch most amateur athletes at least once.
- Cutting intensity along with volume. This is the single most common taper error. It turns the taper into a detraining phase and leaves you flat on race day. Keep the hard work sharp, just shorter.
- Resting too much. A full taper is not 'rest for 2 weeks'. It's reduced training, not no training. A complete rest week leaves most athletes feeling stale, sluggish, and heavy on race morning.
- Adding workouts because you feel good. Taper week is exactly when your body finally starts feeling fresh — and exactly the wrong time to test whether you can handle a bonus session. 'I felt great so I added a tempo run' is how good tapers turn into bad races.
- Under-eating because volume is down. Your body is still repairing and supercompensating. Cut volume, not calories. Ramp carbs before a long race.
- Changing anything new. New shoes, new nutrition, new pre-race routine, new music playlist — save the experiments for B races. Race week is for sticking to what you already know works.
Why does the taper feel so weird?
Almost every experienced endurance athlete has felt what's sometimes called taper tantrums: a cluster of weird sensations that show up in the days before a race and have nothing to do with actual fitness. Your legs feel heavier. Random aches appear. You worry about phantom injuries. Your 5-kilometre tempo run feels harder than it should. You become convinced you've lost fitness overnight.
None of this is a sign that the taper isn't working. The heavy-legs feeling is a well-documented artefact of the body's transition from high-load to low-load training — the nervous system takes a few days to recalibrate, and the result is a temporary perception of heaviness even though force production is actually improving. The phantom aches are your body's repair processes finally getting attention they didn't have during peak training. Trust the process and don't let the feelings rewrite your plan.
Does taper length depend on training age?
Yes. More experienced athletes with higher chronic loads typically need longer tapers because they have more accumulated fatigue to shed. An Ironman-focused athlete carrying a CTL of 120 cannot shake off two months of training in 7 days — they need closer to 2 or 3 weeks.
Less experienced athletes, or athletes with lower training volumes going into a race, can get away with shorter tapers. For a first-time marathoner whose peak week was 70 km, a 10-day taper is often sufficient. The principle is the same, the absolute time scales with the load you accumulated on the way in.
Key takeaways
- A taper is a planned volume reduction that lets fatigue drop faster than fitness, revealing your true capacity on race day.
- Cut volume by 40–60%, keep intensity high, keep frequency roughly the same.
- Race-distance-specific guidance: 5–10 days for 5K/10K, 10–14 days for half and Olympic, 2 weeks for marathon and 70.3, 2–3 weeks for Ironman and ultras.
- Eat to support recovery and ramp carbs before a long race — taper is not a calorie-cutting phase.
- Bank extra sleep across taper week. It's free and effective.
- Never introduce anything new in race week. Trust what you already practised.
- Taper tantrums — heavy legs, phantom aches, subjective sluggishness — are normal and don't mean the taper is failing.
Frequently asked questions
Should I do any hard workouts during my taper?
Yes. Short bursts of race-pace or slightly faster work are the core of a good taper. A typical marathon taper week might include 5 × 2 minutes at marathon pace plus a few strides, or 3 × 1 kilometre at half-marathon pace. The sessions are much shorter than peak training, but they keep your neuromuscular system sharp and prevent detraining. Long slow easy sessions alone during taper week leave most athletes feeling dull.
Is it normal for my legs to feel heavy during the taper?
Yes, extremely normal. The phenomenon is well known enough that coaches have a name for it (taper tantrums). The body takes several days to recalibrate from heavy training to reduced training, and the nervous system's response can feel like sluggishness even though force production is actually improving. Legs almost always feel fine on race morning even when they felt terrible the day before.
Should I carb load for every race?
For any race lasting longer than about 90 minutes, yes. For a marathon, a full Ironman, a half Ironman, or a long ultra, carb loading in the 48 hours before the race (roughly 8–12 g/kg/day) reliably improves performance by keeping muscle glycogen at maximum. For a 5K or 10K, you don't need to carb load in the classical sense — a normal healthy meal the night before and a familiar breakfast are plenty.
Can I skip the taper if I feel great?
No. Feeling great late in a training block is a signal that the training is working, not that you don't need to taper. The benefit of a taper shows up on race day, not in how you feel the week before. Skipping or shortening a taper for a key race is one of the most commonly regretted decisions in endurance sport.
What if I get sick during my taper?
Very common, actually — the transition from high to low load can temporarily depress immune function as your body reorganizes. If you get sick, prioritize full rest and rehydration over maintaining the taper schedule. A minor cold with 2 or 3 days of rest usually costs less than forcing through training while your body fights it off. If illness persists into race week with fever, deep fatigue, or chest symptoms, honor your health over the race entry.
Should my last long run be close to race distance?
Rarely. For a marathon, the last truly long run is usually 3 weeks before race day at most — closer is too close to leave enough time for the body to recover the last training dose. The final long run in taper week is typically 60–90 minutes, not race length. Testing race pace in a short block during the final long run is more valuable than adding distance. See how to structure a long run for the full progression.
How CoreRise runs your taper automatically
Every training plan CoreRise builds includes a taper, scaled to the distance of your race and the amount of load you've accumulated during the training block. You don't have to figure it out from a generic template. When you set a race date in your plan, the final 1 to 3 weeks are automatically constructed around your actual chronic training load, with volume reductions timed to drop your ATL while keeping your CTL mostly intact — the exact dynamic that produces race-day freshness.
Your coach also handles race week specifically. You can ask it to review the schedule, adjust for a minor cold, drop a session if travel ate your Tuesday, or walk you through race-morning execution. After the race, you debrief — what worked in the taper, what felt flat — and the coach remembers that for the next one, so your future tapers get better every year.
- Taper length is chosen automatically based on race distance and your current CTL.
- Volume is reduced while intensity sessions are preserved — the protocol that actually works.
- You can adjust your taper in natural language if your life or body throws a curveball.
- Race week sessions are tuned to keep you sharp without adding fatigue.
- Post-race debriefs make the next taper smarter, not just a copy of the last one.
Antoine Boudet is the founder of CoreRise. He finished Ironman 70.3 Oceanside in 2026 and writes the evidence-based Learn hub articles for runners, cyclists and triathletes, drawing on the research literature and his own training.