A taper makes you 2-6% faster on race day
High confidence
A taper is the wind-down before a race, and it works. In the last week or two, runners cut how much they run by 40 to 60 percent while keeping some speed in their legs. A rough rule is one easy week for every four weeks of hard training. That trade tends to make you 2 to 6 percent faster on race day.
Why it works
Backing off lets built-up fatigue drain away and refills glycogen, the fuel your muscles store. Tissues repair, and your muscles and nerves fire more crisply. Keeping some fast running holds your race-pace fitness in place.
What it means in practice
A good marathon plan tapers over its last 2 to 3 weeks. How much you run drops week by week, but a few faster touches stay in. Be wary of plans at either extreme. Cutting all fast running is too much; holding peak mileage is too little.
The evidence
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Athletes who won Olympic or World Championship gold shared a recurring training pattern in the year before. Volume ran high through the preparatory phase, then fell as competition neared while intensity rose into a structured taper. Their intensity distribution stayed polarized, with most work at low intensity plus targeted high-intensity sessions, and hard days alternated with easy ones. Because only winners were studied and the records are retrospective, this documents what champions did without proving any single element caused the result.
Why we call confidence high
Tönnessen's 2014 'Road to Gold' lays out taper protocols used by elite endurance athletes. The taper effect is one of the most consistent findings in endurance sport science, holding up across decades of study.
Where it applies
Trained adult runners getting ready for a specific race.
Does not apply to: runners with multiple races in close succession; very low-volume training where taper effect is small.
Plans that respect this
Plans that scored well on the rubric measures informed by this claim.
- 10-Week Run Your First 10k (3 days)
- 10-Week Run Your First Half Marathon (3 days)
- 10-Week Sub-1:45 Half Marathon (4 days)
- 10-Week Sub-1:45 Half Marathon (5 days)
- 10-Week Sub-1:45 Half Marathon (6 days)
- 10-Week Sub-40 10k (4 days)
- 10-Week Sub-40 10k (5 days)
- 10-Week Sub-40 10k (6 days)
- 10-Week Sub-45 10k (4 days)
- 10-Week Sub-45 10k (5 days)
- 10-Week Sub-45 10k (6 days)
- 10-Week Sub-50 10k (5 days)
Last reviewed Apr 30, 2026. See how we score.