Marathon Taper: How to Taper for a Marathon

Every marathon plan eventually asks the same question: how much do you actually cut in the final two weeks? Too little and you show up carrying weeks of fatigue. Too much and you lose your edge before the gun goes off. This guide covers the numbers behind a proper marathon taper: how much volume to drop, how long to taper, what to do with intensity, and how to tell if it worked before race day.

What is a marathon taper?

A marathon taper is a planned reduction in training volume over the final 10 to 14 days before the race, while keeping some intensity, so your body can shed accumulated fatigue and arrive at the start line fresh. It works by letting Acute Training Load (ATL, "fatigue") fall faster than Chronic Training Load (CTL, "fitness"), which raises your Training Stress Balance (TSB, "form") into a positive, race-ready range. The taper does not build new fitness. It reveals the fitness you already built.

This is the same Banister/Coggan impulse-response model used in TrainingPeaks' Performance Management Chart: fitness (CTL) is a slow-moving 42-day average of training load, fatigue (ATL) is a fast-moving 7-day average, and form (TSB) is fitness minus fatigue. A taper works because cutting daily training load drains the fast-moving ATL number quickly while the slow-moving CTL number barely moves, so the gap between them (your form) opens up.

How much should you cut your volume?

Cut weekly training volume by roughly 40 to 60 percent by the final few days before the race, tapering down gradually rather than all at once. An "A" race (your primary goal) calls for the more aggressive 40 percent target; a "B" race (a tune-up or secondary goal) calls for the more moderate 60 percent target. Cutting sharply on day one and holding flat there is a common mistake; a smooth, geometric decline lets fatigue clear without wasting the fitness you built.

Here is a 14-day taper for an A-race, showing training load as a percent of your normal daily average:

Days to race	Training load (% of normal)
14	100%
12	87%
10	75%
8	66%
6	57%
4	49%
2	43%
1	40%
0 (race day)	0%

This is a smooth geometric decline, not a straight-line cut: the drop is gentle at first and steepens as race day approaches. The TSS and taper planner runs this exact model against your own CTL and ATL (pulled from Strava or entered manually) instead of a generic table, and tells you whether the resulting form actually lands in the peaked zone.

How long should a marathon taper be?

Most marathoners should taper for 10 to 14 days. Shorter tapers (about 7 days) suit athletes racing frequently or carrying less accumulated fatigue; longer tapers (up to 14 days, occasionally more for high-mileage runners) suit athletes coming off a heavy peak training block. Tapering much longer than two weeks risks losing fitness faster than you shed fatigue, since CTL decays too.

Taper length	Best for
7 days	Lower weekly mileage, frequent racing, minimal fatigue built up
10 days	Most marathoners on a standard 16 to 18 week plan
14 days	High-mileage runners (60+ mi/week) coming off a heavy peak block

Should intensity drop during a taper too?

Intensity should not drop nearly as much as volume. Keep short bouts of race pace or slightly faster work throughout the taper, just at a much lower total volume, so your legs stay sharp instead of going stale. A taper built entirely from easy jogging often leaves runners feeling flat and heavy-legged on race morning, a well-documented phenomenon among coaches even though total training stress is low.

A simple pattern that works for most plans: keep one shorter session per week at or near marathon pace (for example, 3 to 4 x 1 mile at goal pace with full recovery), drop your long run to 8 to 10 miles with a few race-pace miles inside it, and make every other session easy or off entirely.

How do you know if your taper worked?

Your taper worked if your Training Stress Balance (TSB) lands between +5 and +25 on race morning: fresh enough to hold pace, not so rested that you feel flat. Below zero means you are still carrying fatigue; above +25 usually means you cut too much and lost sharpness. This is the single number that separates a "did I taper enough" guess from an actual answer.

TSB on race day	What it means
Below 0	Still fatigued, racing tired
0 to +5	Slightly under-peaked, a touch more rest would help
+5 to +25	Peaked: the target zone
Above +25	Over-tapered, add a short race-pace opener

The TSS and taper planner projects this number for you day by day instead of leaving it to feel, using your actual training load rather than a generic taper template.

Common marathon taper mistakes

The most common taper mistakes are cutting volume too late, dropping intensity along with volume, tapering for too long, and eating like a taper week instead of adjusting calories down with training load. Any one of these can undo weeks of otherwise solid preparation.

• Starting the cut too late. A taper that only begins 3 to 4 days out does not give ATL enough time to fall relative to CTL.
• Cutting intensity, not just volume. All-easy tapers frequently leave runners flat. Keep short, race-pace-adjacent work.
• Overdoing the taper length. Longer than 2 to 3 weeks starts eating into fitness (CTL), not just fatigue.
• Not adjusting food intake. Training volume drops but appetite often does not; carrying extra weight into race week is common and avoidable.
• Panicking mid-taper. Feeling sluggish 5 to 7 days out is normal (a temporary dip before form rises); adding a hard workout to "feel better" usually backfires.

Once your taper is dialed, the last piece is fueling: see carb loading for the 1 to 3 day glycogen-loading protocol that pairs with the final taper days, and how to pace a marathon for turning that fresh form into an even split on race day.

Frequently asked questions

How long should you taper for a marathon?

Most marathoners should taper for 10 to 14 days. Runners with lower weekly mileage or frequent racing can taper as short as 7 days, while high-mileage runners coming off a heavy block often need the full 14 days to shed accumulated fatigue.

How much should you reduce mileage during a marathon taper?

Cut weekly volume by roughly 40 to 60 percent by the final few days, tapering down gradually rather than all at once. An A-race goal calls for the more aggressive 40 percent cut; a B-race or tune-up calls for a more moderate 60 percent cut.

Should you still run fast during a taper?

Yes. Keep short bouts of race pace or faster work throughout the taper at a much lower total volume. Dropping intensity along with volume is a common mistake that leaves runners feeling flat and heavy-legged on race morning.

What is a good taper for a half marathon versus a full marathon?

A half marathon taper is typically shorter and less aggressive, around 7 to 10 days with a 30 to 40 percent volume cut, since half-marathon training carries less accumulated fatigue than full-marathon training. A full marathon taper runs 10 to 14 days with a deeper cut.

How do you know your taper is working?

Your Training Stress Balance (TSB) should rise into the +5 to +25 range by race day. Below zero means you are still fatigued; above +25 usually means you over-tapered and lost sharpness. The TSS and taper planner tracks this number day by day from your actual training load.