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Your First Half Marathon: Complete Guide & Training Plan

Your First Half Marathon: Complete Guide & Training Plan

Everything you need to know to prepare, run, and finish your first 21.1 km race

Prepare my first half

The half marathon (21.1 km / 13.1 miles) is the perfect distance for a first big race: ambitious enough to be a real challenge, yet achievable with 3 to 4 months of preparation. Whether you simply want to cross the finish line or hit a specific time, this guide has you covered from A to Z. RunRun offers a 12-week plan designed for runners who have never raced this distance.

Pourquoi choisir RunRun ?

12-week plan

3 to 4 sessions per week with progressive volume increase. The plan starts at 25 km/week and peaks at 40-45 km.

70% easy running

The foundation of half marathon training is endurance. Run slowly to run longer. Speed work is just one session per week.

Progressive long run

The key half marathon workout. From 12 km in week one to 18-20 km before race day. This is where endurance is built.

Race-pace work

From week 5, we include portions at half marathon pace to learn race-day rhythm management.

Injury prevention

Recovery week every 3 weeks. Stretching, strength training and body awareness to arrive healthy at the start line.

Race strategy

Fueling plan, pacing strategy, conservative start. Don't go out too fast to finish strong.

12-week half marathon plan — First timer

S1

Week 1 — Getting started

3 sessions, ~25 km. Establishing training rhythm.

  • Tuesday: 40 min easy run
  • Thursday: 45 min easy with 4×30s progressive accelerations
  • Sunday: Long run 1h (10-12 km)
S4

Week 4 — Building volume

4 sessions, ~35 km. Introducing intervals.

  • Tuesday: 45 min easy
  • Wednesday: 10 min easy + 6×1000m at 10K pace (90s recovery)
  • Friday: 40 min easy
  • Sunday: Long run 1h15 (14-15 km)
S8

Week 8 — Race-specific block

4 sessions, ~40 km. Half marathon pace work.

  • Tuesday: 45 min easy
  • Wednesday: 15 min easy + 3×2km at half marathon pace (2 min recovery)
  • Friday: 45 min easy with 6×30s hill sprints
  • Sunday: Long run 1h30 with 30 min at half marathon pace (17-18 km)
S11

Week 11 — Taper

3 sessions, ~25 km. Progressive reduction to arrive fresh.

  • Tuesday: 40 min easy
  • Thursday: 30 min easy + 3×1km at half marathon pace (2 min recovery)
  • Saturday: 30 min very easy shakeout run
S12

Week 12 — Race day

Final short sessions and the big day.

  • Tuesday: 25 min easy with 3×30s accelerations
  • Thursday: 20 min very easy
  • Sunday: RACE — your first half marathon!

Tips to nail your first half marathon

1

Test everything in training

Shoes, outfit, nutrition, hydration: nothing new on race day. Test your gels and breakfast during long runs.

2

Start slow for the first 5 km

The #1 beginner mistake: starting too fast carried by race-day adrenaline. Aim 10-15 seconds slower than target pace at the start.

3

Fuel regularly

Drink at every aid station (every 20-25 min). Take a gel or carbs around km 10-12. Don't wait until you're thirsty or hungry.

4

Manage the km 15 wall

This is often where it gets tough. Focus on your stride, breathe, and remember the last 6 km are your victory lap.

5

Pre-race breakfast

Eat 3 hours before the start. Something digestible and familiar: toast, honey, banana. Avoid fiber and fat.

Questions fréquentes

What level do I need to run a half marathon?

You should be able to run 45 minutes to 1 hour non-stop. If so, 12 weeks of preparation is enough to complete a half marathon.

What time should I aim for on my first half?

Don't target a specific time for your first half. The goal is to finish. On average, a first half marathon is completed between 2h00 and 2h30.

Should I eat during a half marathon?

Yes. Plan to drink at every aid station (about every 5 km) and take a gel or equivalent around km 10-12 to maintain energy.

Can I walk during the race?

Absolutely! Many runners walk at aid stations or on hills. The point is crossing the finish line. Walking is not failing.

How do I choose my first half marathon?

Pick a flat course, a well-organized race (frequent aid stations, good atmosphere), and a date that gives you at least 12 weeks to prepare.

Start your half marathon training

Set your half marathon goal on RunRun and get a free personalized training plan adapted to your level.

Prepare my first half