What Actually Happens During a Marathon Taper

By Coach Nic Baxter | NBx Running Coach

Right now I'm about two weeks out from the Sydney Marathon, just into my own taper. And I can tell you honestly, it feels strange every single time, no matter how many times you've done it before.

Your legs feel heavy. Your mileage drops off a cliff. You start wondering if you've somehow lost all the fitness you worked so hard to build. If you're currently tapering for a race, or about to start, I want to walk you through exactly what's happening in your body, because understanding the process makes it so much easier to trust it.

WHAT IS A TAPER, EXACTLY?

A taper is the planned reduction in training volume in the final 2-3 weeks before race day. Intensity generally stays similar or only decreases slightly, but the total amount of running drops significantly, often by 40-60% compared to peak training weeks.

It is not rest. It is not doing nothing. It is a carefully engineered reduction designed to let your body absorb months of hard training and arrive at the start line in the best possible condition.

Reduce your load. Take a walk and let your body absorb months of hard training

WHAT'S ACTUALLY HAPPENING IN YOUR BODY

Your muscles are repairing microscopic damage. Every hard training session creates tiny amounts of muscle damage that your body repairs during recovery. Months of consistent training means an accumulation of this damage that hasn't been fully repaired. The taper gives your body the time and resources to finish that repair work properly.

Your glycogen stores are replenishing fully. Glycogen, your muscles' primary fuel source, gets depleted through weeks of hard training and often isn't fully restocked between sessions during a heavy training block. Reduced volume allows your glycogen stores to top up completely, giving you maximum fuel reserves for race day.

Your immune system gets a chance to recover. Heavy training suppresses immune function. This is part of why runners often get sick during peak training weeks or shortly after a big race. The taper reduces this training stress, allowing your immune system to strengthen back up before the demands of race day.

Your central nervous system recovers. Training doesn't just fatigue your muscles, it fatigues your nervous system too. Reduced volume allows your nervous system to fully recover, which is part of why many runners report feeling fast and springy on easy runs during a taper. Your body genuinely is recovering strength and power, even though it might not feel that way.

Connective tissue gets time to strengthen. Tendons and ligaments adapt more slowly than muscles do. The taper period allows this slower-adapting tissue to catch up with the fitness gains your cardiovascular system has already made, reducing your injury risk heading into race day.

WHY THE TAPER FEELS SO STRANGE

Almost every runner experiences the same unsettling sensations during a taper:

Heavy legs that don't match the reduced training load. Doubts about fitness, despite months of hard evidence to the contrary. Restless energy from suddenly having far more free time. A nagging feeling that you should be doing more, not less.

All of this is completely normal. It even has a name among coaches and sports psychologists; taper madness. Knowing that it's expected, and that it happens to virtually every runner before every race, makes it much easier to sit with the discomfort rather than panic and add extra unplanned miles.

WHAT NOT TO DO DURING A TAPER

The single biggest mistake runners make during a taper is trying to "make up" for perceived lost fitness by squeezing in extra sessions or pushing pace on easy runs. This defeats the entire purpose of the taper and can leave you more fatigued rather than less on race day.

Trust the plan. The fitness is already built. The taper is not the time to build more, it's the time to protect what you've already earned.

Sydney Harbour Bridge. (AI Image).

HOW TO MAKE THE MOST OF YOUR TAPER

Sleep more, not less. This is genuinely one of the most valuable things you can do in these final weeks.

Fine-tune your race day logistics rather than your fitness; nutrition plan, gear, travel arrangements, pacing strategy.

Keep some intensity in your remaining sessions, just at reduced volume, short strides or brief pickups keep your legs feeling sharp without adding fatigue.

Practice your race morning routine; breakfast timing, warm up, what you'll wear, so nothing feels unfamiliar on the day itself.

Give yourself permission to feel strange. The heavy legs, the doubt, the restlessness-it is all part of the process, and it passes.

MY OWN TAPER, RIGHT NOW

As I write this I am in my own taper for Sydney. My legs feel exactly as heavy as I'm telling you they should. I have had exactly the doubts I'm describing here. And I am trusting the process completely, because I know precisely what is happening beneath the surface. My body is quietly finishing the work that months of training started.

If you're tapering for a race right now, or about to begin, know this: the strange feelings are not a sign of losing fitness. They are a sign the plan is working exactly as it should.

Trust it. Rest well. And get ready to run the race your training has actually prepared you for.

If you'd like expert guidance through your own training block and taper — I'd love to help.

Book your free 30-minute intro call at nbx-runningcoach.com

Coach Nic Baxter is an RRCA Level 2 Run Coach and ACE-Certified Personal Trainer based in Morristown, NJ. She is currently tapering for the Sydney Marathon on 30th August 2026.