What a taper does
Hard training builds fitness and fatigue at the same time. A taper is the short period before a race when you cut back enough for the fatigue to clear while keeping the fitness. Done well, it is one of the cheapest performance gains in running: research on endurance athletes typically finds improvements of around 2–3 %, worth several minutes over a marathon.
What the research says
A widely cited meta-analysis of tapering studies (Bosquet and colleagues, 2007) found the largest performance gains when athletes:
- Cut training volume by about 41–60 %, gradually rather than all at once;
- Kept the intensity: workouts at race pace and faster stay in, just shorter;
- Kept the frequency: the same number of runs per week, each one shorter;
- Tapered for about two weeks, with tapers of one to three weeks also working well.
A 2023 meta-analysis of endurance athletes reached the same conclusions about volume, intensity and frequency (Wang and colleagues, 2023). Marathoners usually taper for about three weeks because the long runs take longer to recover from; for 5K and 10K races, 7–14 days is plenty.
Standard taper percentages
These are the weekly volumes the calculator uses, as a percentage of your peak week. Race-week figures exclude the race itself.
| Race | 3 weeks out | 2 weeks out | Race week |
|---|---|---|---|
| Marathon / 50K | 75 % | 60 % | 40 % |
| Half marathon | — | 70 % | 45 % |
| 10K / 5K | — | 70 % | 50 % |
For a runner peaking at 60 km (37 miles) a week, a standard marathon taper is about 45, 36 and 24 km (28, 22 and 15 miles) in the last three weeks, plus the race. Gentle and aggressive styles shift each week by about 5–10 percentage points.
Long runs and workouts during the taper
Last long run
For a marathon, the last genuinely long run is usually three weeks out, at about three-quarters of your longest. Two weeks out, keep it to about half to two-thirds.
Keep some speed
Keep one quality session a week at goal pace or threshold, just shorter. Dropping all intensity is the most common taper mistake and leaves legs feeling flat.
Same rhythm
Run on the same days you normally do. Cut each run shorter rather than adding rest days.
Strides
Add 4–6 relaxed 20-second strides after easy runs in race week to keep your legs feeling quick.
Race week
Race week is about arriving fresh and fuelled. Keep running most days, but short and easy, with one brief session at goal pace early in the week and a little sharpening a couple of days out. The day before can be rest or a 15–20 minute shakeout, whichever you are used to. For a marathon or half, start carbohydrate loading 36–48 hours before the start: work out your targets with the carb-loading calculator and plan in-race gels with the race fueling calculator.
“Taper madness” is normal. Many runners feel sluggish, restless or even slightly heavier during a taper. This is expected as your body stores more glycogen and water. Trust the plan; do not squeeze in extra miles to “test” your fitness.
Common taper mistakes
- Cutting too much, too soon. Dropping to almost nothing for two weeks loses sharpness. Follow the gradual steps.
- Cutting intensity instead of volume. Keep short, fast running; trim the easy mileage.
- Cramming a missed long run. If you missed training, accept it. A late long run cannot add fitness, only fatigue.
- New things in race week. No new shoes, foods or workouts.
Plan backwards from race day with the training start date calculator, and check your build-up with the weekly mileage calculator.
- Bosquet L, Montpetit J, Arvisais D, Mujika I (2007). Effects of tapering on performance: a meta-analysis. Med Sci Sports Exerc 39(8):1358–1365.
- 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 18(5):e0282838.
- Mujika I, Padilla S (2003). Scientific bases for precompetition tapering strategies. Med Sci Sports Exerc 35(7):1182–1187.
Last reviewed: September 2026 · Health disclaimer