How to Taper for a Marathon: 2-3 Week London Marathon Plan

Tapering is the final and most misunderstood part of marathon training. You’ve spent months grinding out long runs in sideways rain, questioning your life choices on treadmill sessions, and convincing yourself that running repeatedly around a small oval is “character building”. Now, suddenly, you’re supposed to do… less.

This guide explains exactly how to handle tapering for the London Marathon, how much to cut back, which runs to keep, how to survive the mental wobble, and how to avoid the mistakes that ruin months of work.

If you get this right, you arrive on the start line fresh, confident, and ready. If you get it wrong… well, let’s not do that.

What Is Marathon Tapering (And Why It Matters)

Marathon tapering is the planned reduction of training volume in the final 2–3 weeks before race day. The aim is simple:

• Let muscles repair
• Restore glycogen stores
• Reduce accumulated fatigue
• Maintain fitness

Research shows that a structured taper can improve marathon performance by 2–3% which is several minutes for most club runners.

According to RunnersConnect, runners who reduce volume but keep some intensity consistently outperform those who either over-rest or keep training too hard.

Translation: rest, but not too much.

Your 3-Week London Marathon Taper Plan

3 Weeks Before Race Day

This is where tapering starts gently.

Mileage: Reduce by around 10–20%

If you peaked at 50 miles per week, aim for around 40–45.

Long Run: Reduce by 15–20%

A 20-mile run becomes 16–17 miles.

Key Session: One marathon pace or tempo workout

Example:

• 2 × 3 miles at marathon pace
• 10-mile steady with middle section at race pace

Everything else should be easy. Proper easy. Not “accidentally tempo” easy.

2 Weeks Before Race Day

This is the most important taper week.

Mileage: Reduce to 70–75% of peak

Long Run: About 10–12 miles

Key Session: Shorter marathon pace workout

Example:

• 6–8 miles including marathon pace
• 4 × 1 mile at race pace

According to Runner’s World, most of your fitness is locked in by this point. You cannot gain more. You can only lose it.

No hero workouts. No “just testing myself”. That way lies regret.

Race Week

Welcome to the paranoia phase.

Mileage: 50–60% of normal

Runs: Short, relaxed, confidence-boosting

Typical week:

• Mon: 4–5 miles easy
• Wed: 5 miles with 3 × 3 min at race pace
• Fri: 3 miles easy
• Sat: 2-mile shakeout

Many elite and amateur runners follow this pattern, including guidance from London Marathon training resources.

You are not getting fitter this week. You are getting fresher.

How Much Should You Reduce Mileage?

A proven tapering structure looks like this:

• 3 weeks out: 80–90%
• 2 weeks out: 70–75%
• Race week: 40–60%

Don’t slash volume overnight. That’s how you end up feeling heavy, flat, and strangely ill.

Also keep your running frequency similar. If you usually run 5 days per week, keep running 4–5 days. Just shorten the runs.

Your body likes routine.

Which Runs Should You Keep?

During marathon tapering, you keep three types of runs:

Easy Runs

These maintain circulation and routine. They help recovery and stop you feeling like you’ve forgotten how to run.

Marathon Pace Sessions

Short, controlled workouts at race pace build confidence.

They remind your legs what “comfortable discomfort” feels like.

Strides and Light Fartlek

Short bursts keep neuromuscular sharpness.

Example:

• 6 × 20-second strides after easy runs
• 6 × 2 minutes at race pace

Nothing should leave you destroyed.

Fueling During the Taper

This is where I got it wrong last year.

I tapered too hard, ran too little, and started “carb loading” about ten days early.

Result: heavier legs, sluggish runs, and the physical shape of a stressed-out potato.

Lesson learned.

According to Runner’s World UK, carb loading should mainly happen in the final 48–72 hours.

Before that:

• Eat normally
• Prioritise carbs
• Keep protein high
• Don’t binge

Final 3 days:

• Increase carbs gradually
• Reduce fibre
• Smaller, frequent meals

You want full glycogen stores, not food regret.

The Mental Battle of Tapering

The taper messes with your head.

Common symptoms include:

• Feeling slow
• Doubting training
• Random aches
• Obsessive weather checking
• Googling “missed long run marathon success” at 2am

This is normal.

Strava’s annual running reports show most runners reduce training by over 40% in the final week, yet still perform at peak levels on race day.

Your body is absorbing training. That feels like tiredness.

Trust it.

Common Marathon Tapering Mistakes

Over-Tapering

Stopping too much, too soon.

Leads to flat legs and lost rhythm.

Cutting All Intensity

No race pace = no confidence.

Early Carb Loading

Learn from my mistake. Wait until race week.

Panic Training

Adding “one last hard session” is the fastest way to get injured.

Trying New Things

New shoes. New gels. New routes. New mistakes.

Stick to what works.

My Biggest Taper Lesson

For my last marathon, I cut mileage too aggressively and treated tapering like an eating competition.

I thought I was “being sensible”.

I was sabotaging myself.

Now my approach is simple:

• Reduce mileage gradually
• Keep quality sessions
• Eat normally until race week
• Trust the process

Much better results. Much less stress.

Final Thoughts: Trust the Taper

Tapering feels wrong because running culture rewards suffering.

Less running feels like cheating.

It isn’t.

It’s the final phase of training.

Do it properly, and you arrive at the London Marathon start line confident, rested, and ready to enjoy the madness.

Do it badly, and you’ll spend 26.2 miles asking yourself why you do this to yourself.

Choose wisely.