New research · 4 min read · 2026-10-11
Three weeks of tapering before a marathon
In more than 158,000 marathon runners, a steady three-week taper was linked to finishing about 2.6 percent faster.
In the last weeks before a marathon it is tempting to squeeze in one more long run. A study of more than 158,000 marathon runners suggests that easing off earlier may pay off on race day.
What the researchers did
Researchers in Dublin looked at the training logs of recreational marathon runners in the weeks before their race. They compared runners who cut their weekly distance steadily over the last three weeks with runners who barely tapered at all.
What they found
Runners who reduced their distance week by week for three weeks finished about 2.6 percent faster than comparable runners with a minimal taper. For a four-hour marathon that is around six minutes. Women seemed to gain a little more from the same taper than men.
Most runners didn't taper like that. About two thirds had a shorter or less consistent taper.
What it means for you
Plan your last three weeks before the marathon so that each week is a bit shorter than the one before. Resist the urge to make up for missed training in the final weeks. The fitness you have three weeks out is the fitness you take to the start line.
What the study can't tell you
The study compares runners who chose different tapers. It can't rule out that the runners who tapered well were also better prepared in other ways. It also says nothing about shorter races, where a shorter taper is usually enough. Elite marathon runners often start their taper 7 to 10 days before the race, but they also train far more than most of us.
How we use it
In PX7 Training the taper is planned backwards from your race date, and the length depends on the race distance. When a plan is rebuilt after a break, the taper still lines up with race day.
Sources
- Smyth & Lawlor (2021), Longer disciplined tapers improve marathon performance for recreational runners. Frontiers in Sports and Active Living.
- Haugen et al. (2022), The training characteristics of world-class distance runners. Sports Medicine – Open.
Written by Jørgen Larsen for PX7 Training.