2026-05-24 · 5 min read
Advanced tapering — dropping load without losing fitness for race day
The taper is where most people blow up good races. After months of solid training, the last 2-3 weeks can torch the whole block if they're not managed deliberately. And most folks manage them by gut feel, not evidence.
Here's what to understand, based on what the studies from Iñigo Mujika, Laurent Bosquet, and David Pyne say — the three researchers who have done the most work on this in the last 25 years.
What the taper is for
Two things at once, and they look contradictory:
1. Wipe out accumulated fatigue (high ATL from the hard weeks).
2. Hold onto the fitness you built (high CTL, physiological adaptations, efficiency).
Drop volume the wrong way and you lose fitness without shedding fatigue (worst of both worlds). Drop it right and you arrive with TSB in the positive range (+5 to +20) and every adaptation intact.
The best-studied rule: Bosquet 2007
Meta-analysis of 27 studies. Central conclusion:
A 2% improvement on a marathon is 2-4 minutes. On a 10K, 30-60 seconds. That's not nothing.
What people get wrong
### 1. Dropping intensity too
The most expensive mistake. People think "if I rest, I rest from everything." Wrong. Cut quality work and you lose VO2max and threshold adaptations in 7-10 days. Hard reps stay, just in smaller doses.
Right: if you've been doing 6 × 800m at 10K pace, in taper week you do 3 × 800m at the same pace. Same intensity, less volume.
Wrong: swap 6 × 800m for an easy Z2 jog "so I don't get tired." You'll line up flat.
### 2. Taper too long
More than 3 weeks of taper for most amateurs is counterproductive. You start losing CTL faster than the residual fatigue can clear.
Exception: 100K+ ultra trail. There 3 weeks makes sense because the accumulated fatigue is deeper.
### 3. Taper too short
Less than 7 days doesn't work either. Muscle fatigue and glycogen depletion need at least a week to fully clear. If you line up with TSB at -10 or -15, you'll suffer.
### 4. Changing everything during taper
It's the worst time to try new shoes, a new gel, a new pace, new supplements. Everything that's going to race needs to be tested two weeks out.
The concrete protocol I'd run
Assuming you're coming off 4-12 weeks of a hard block and the race is a half or full marathon:
### 14 days out
### 11-10 days out
### 7-6 days out
### 4-3 days out
### Day -2
### Day -1
### Day 0
What it looks like in TSB
If you came in at CTL 65 and ATL 80 (TSB -15, fatigued), a well-run taper looks like:
Vetta shows you a 14-day projected TSB if your goal is loaded. If you see yourself landing negative, you adjust before, not the day-of.
Important detail: fiber type
Athletes with a more explosive profile (5K-10K specialists) need a RELATIVELY LONGER taper. Their type II fibers take longer to recover from VO2max sessions.
Pure distance athletes (HM/marathon/ultra) can taper shorter and keep more residual volume. Their adaptations are more stable.
If you don't know which you are: run a standard 10-12 day taper and log how you feel. Next time you have a data point.
Most important: trust
The last big mistake of the taper is doubting the weeks you put in. People hit 4 days out and think "wait, maybe I didn't train enough" and slip in a hard session "just to lock it in." That session never adds anything — it just steals the rest you need.
The block is done. The taper isn't training — it's protecting what's already trained. Trust it.
In Vetta
The planning engine has `VOLUMEN_POR_FASE` with values from Mujika+Padilla 2003 for every discipline. The taper phase drops volume from 22% to 38% depending on the sport (running -22%, cycling -38%, swimming -35%). The `long` and `strength_endurance` families get filtered out in taper. If you have a goal loaded and the race is 2 weeks away or less, the engine flips automatically into taper phase.
[Start your plan with Vetta →](/signup) — the taper builds itself around your goal and race date.