The taper is the two-to-three week period before a marathon where you deliberately reduce training load so your body can absorb months of accumulated fatigue and arrive at the start line rested, not just fit. It's also, for most runners, the psychologically hardest part of marathon training — after months of building mileage, suddenly running less can feel like you're losing fitness right when it matters most. You're not.
Why tapering works
Training doesn't make you fitter directly — it creates a stimulus (fatigue) that your body then adapts to during recovery. During a heavy training block, you're accumulating fatigue faster than you can fully recover from it, which is intentional: that's how fitness builds over months. The taper is the point where you stop adding new stimulus and let weeks of accumulated adaptation actually surface.
Research and decades of practical coaching experience agree on the broad shape of an effective taper: significantly reduced volume, but maintained or only slightly reduced intensity. Cutting both volume and intensity too aggressively can leave legs feeling flat and sluggish on race day — a phenomenon often described as 'taper flu' or dead-leg syndrome, distinct from actual illness.
How much to reduce your mileage
| Weeks before race | Volume vs. peak week | What to keep |
|---|---|---|
| 3 weeks out | ~75-80% | One more moderately long run; keep your usual weekly session structure. |
| 2 weeks out | ~60% | Shorten the long run further; keep a shortened version of your usual quality session at race-relevant pace. |
| Race week | ~30-40% | A few short runs, including some at goal race pace, to keep legs sharp — not to build fitness. |
These are general guidelines, not rigid rules — someone running 70 miles/week in peak training tapers differently in absolute terms than someone running 30. The key principle that holds regardless of your baseline: cut volume substantially, but don't cut intensity to zero. A few short, race-pace efforts during taper week keep your legs feeling sharp rather than flat.
The most common taper mistake
Doing nothing at all. Complete rest for two weeks isn't a taper — it's detraining. Legs that haven't turned over at any real pace in 10 days often feel heavy and unresponsive on race morning. Reduced, not eliminated, is the goal.
Nutrition during the taper
Since you're training less, your calorie needs drop too — this is the moment many runners accidentally gain a little water weight and panic, mistaking normal glycogen-and-water storage for fat gain. As you taper, your muscles are storing extra glycogen (each gram of stored glycogen binds with roughly 3 grams of water) in preparation for race day. A small, temporary weight increase in the final week is a sign your carb-loading and reduced training are working, not a problem.
A genuine carbohydrate-loading phase — deliberately increasing carbohydrate intake — is most effective in the final 2-3 days before the race, not for the full two weeks. Trying to "carb load" for two straight weeks just adds unnecessary calories without the glycogen-supercompensation benefit that comes from combining reduced training with a short, focused increase in carbs right before race day.
Sleep, mindset, and managing taper anxiety
Taper anxiety — the nagging feeling that you're losing fitness, getting slower, or somehow "un-training" — is close to universal, and it's worth naming explicitly so it doesn't derail your plan. The evidence and the accumulated experience of essentially every experienced marathoner point the same direction: trust the process, resist the urge to squeeze in one more big session to "make sure," and treat restlessness as a normal symptom of tapering, not a signal that something's wrong.
Prioritizing sleep in the final week matters more than any single training decision at this point — there's little upside left to extract from training, but a poor night's sleep before race day (common, given nerves) is far less costly if you've been banking good sleep in the days before.
A simple race-week checklist
- Confirm race-day logistics early in the week — travel, parking, bag drop, start time — so it's off your mind by the weekend.
- Lay out or pack race kit several days out, including anything you'd need for unexpected weather.
- Keep runs short and include a few strides or short efforts at goal pace, not just easy jogging.
- Increase carbohydrate intake meaningfully in the final 2-3 days, not the full week.
- Prioritize sleep from several nights out — the night immediately before race day is often disrupted by nerves regardless of what you do.
- Avoid trying anything new in the final week — new shoes, new gels, new routes — even if it seems like a good idea in the moment.