You're Probably Tapering Wrong

A few weeks before your race, your training plan tells you to back off. You cut your miles, run slower than you have in months, and start wondering if you're losing fitness. By race week your legs feel heavy and dull. You feel slower than you did mid-training. You question everything.

A 2 to 3 week taper is right. Studies have shown this consistently for over 20 years. The problem is most runners do it wrong. They cut back in the one way that actually hurts them on race day.

What Does Research Say About Tapering for Ultramarathons?

A 2007 review pooled 27 studies of competitive athletes.¹ The best results came from a 2 week taper that cut training volume by 41 to 60 percent. Athletes usually race about 3 percent faster after a good taper.⁴ Not because rest is magic, but because your body finally has time to do three things: repair the muscle damage from months of hard training, top off your energy stores, and lock in the fitness gains you've already built. A 2011 review of top triathletes backed up these findings.²

The key finding: the taper worked best when athletes kept their hard efforts. Cutting how hard they trained did not help. The taper works because you cut the miles but keep the hard efforts. That is what the Iron Miles Training Planner is built around: quality sessions stay in as volume backs off.

What Is the Most Common Taper Mistake?

Most runners hear "taper" and think it means run easy for a few weeks. That's wrong. Easy miles don't hold onto the fitness you've built. Without some hard efforts during the taper, you can start to lose some of the fitness you built.³

Keeping a little hard running in your week is what holds your fitness while you rest.³ Cut the miles. Keep the effort.

What Training Should You Keep During the Taper, and What Should You Cut?

Keep

• One hard session per week in weeks 3 and 2: tempo intervals, hill repeats, or race-pace running. Make it shorter than normal, but keep the same effort level.
• Strides two or three times per week: short 8 to 10 second bursts at a fast pace with full rest between. They cost very little in terms of recovery and keep your legs feeling sharp.
• Your normal number of run days. Don't drop runs entirely. Just make each one shorter.

Cut

• Back-to-back long runs: replace the weekend double with one moderate long run at easy effort.
• Long run distance: bring it down a lot from your peak. If your longest run was 3 hours, aim for 90 to 100 minutes in week 3, then 60 to 75 minutes in week 2.
• Hill and climbing volume: unless your race is in the mountains, cut the big vert. One short steep run in week 2 is enough to keep your legs ready.
• Heavy leg work in the gym: stop the heavy lifting 10 days before race day. Light activation work is still fine.

Why You Feel Worse Before Race Day

Most runners hit week 2 of a taper feeling flat, heavy, and slower than they did a few weeks earlier. Legs that felt good during peak training feel sluggish. Your easy pace feels harder than it should. The urge is to go back to hard training, or to spend race week convinced you've lost your fitness.

Here is what is actually happening. When your muscles restock glycogen (the fuel stored inside them), they pull water in along with it. That makes your legs feel heavy. At the same time, small tears in muscle fibers from months of hard training are healing up. Your immune system, which runs lower during hard training, gets more active again. All of this happens at the same time and all of it feels like a step backward. None of it is fitness loss.

Studies of tapering athletes often find less tiredness and a better mood by race day.⁴ Some heavy-leg days along the way are normal. If you feel flat for a week or more, you may have cut too many runs. Keep a few hard sessions and most of your usual run days.

How Much Does Sleep Matter in Race Week?

A 2026 lab study had 16 recreational runners stay up all night. The next day, they took fewer steps per minute and spent longer on the ground with each step. They also tired out 13% sooner on a hard effort.⁵ That was a full night with no sleep, which is much worse than the restless night most runners get before a race. Still, it's a good reason to protect your sleep all through race week.

How Long Should You Taper for a 100-Mile Race?

Some elite athletes run a lot of miles in the days right before a big race. That makes sense for them. An athlete who runs 200-plus miles per week has a "reduced" taper week that still involves more total running than most people do at their peak. Their bodies have adjusted to that load over many years. A long taper at their scale would leave them more rusty than ready.

The same idea works in reverse. Shorter races need shorter tapers. If you trained for a 50K at 50 miles per week, 10 to 14 days of lower mileage is usually enough. A 100-miler with months of 80 to 100 mile weeks needs the full 2 to 3 week window.

The rule that holds across all of this: how long and how much you taper should match how much you trained and how far you're racing. And keep some hard efforts in there no matter what.

Should You Do Strength Training During the Taper?

Don't quit strength training entirely during the taper. Muscles that have been worked twice a week for months will lose their gains faster than your running fitness if you just stop. Here's how to scale it back:

• Week 3: do about 30 percent less volume. Same weights, just fewer sets.
• Week 2: light activation work only. Single-leg squats, calf raises, light hip exercises. No heavy lifting.
• Race week: 10 minutes of easy activation on run days. Nothing the day before the race.

For the full strength protocol and why leg strength matters so much in the second half of a 100-miler, see Why Your Legs Quit at Mile 60.