How to Train for a Half Marathon

A 12-week plan to take you from comfortable 10K runner to confident half marathon finisher at 13.1 miles.

Key Takeaways

  1. You should be able to run 6+ miles comfortably before starting this plan. If not, complete the 10K training plan first.
  2. The plan uses 4–5 running days per week with a progressive long run that peaks at 11–12 miles before race day.
  3. You don't need to run 13.1 miles before race day. Your longest training run is 12 miles — race-day adrenaline and tapering carry you the final distance.
  4. The half marathon is the first distance where fueling and hydration during the race become important factors in performance.

Prerequisites

This plan assumes you can comfortably run 6 miles and are logging 15–20 miles per week. You should have completed at least one 10K race or training cycle. If you're running fewer than 15 miles per week, spend 4–6 weeks building your base before starting.

You'll need:

The 12-Week Half Marathon Training Plan

This plan has 4–5 run days per week: 2–3 easy runs, 1 quality workout, and 1 long run. Cross-train or rest on remaining days.

Week Easy Runs Quality Workout Long Run Weekly Total
13–4 mi × 320 min tempo6 mi~20 mi
23–4 mi × 35 × 800m at 5K pace7 mi~22 mi
34 mi × 325 min tempo8 mi~24 mi
43–4 mi × 2Easy 3 mi + strides5 mi easy~16 mi (recovery)
54 mi × 34 × 1 mi at 10K pace, 2 min jog9 mi~26 mi
64 mi × 330 min tempo10 mi~28 mi
74 mi × 35 × 1K at 5K pace, 2 min jog8 mi~24 mi
84–5 mi × 335 min tempo11 mi~30 mi
94 mi × 33 × 2 mi at half marathon pace12 mi~30 mi
104 mi × 330 min tempo10 mi~26 mi
113–4 mi × 34 × 800m at 5K pace8 mi~22 mi
123 mi × 220 min easy + 4 stridesRace day — 13.1 mi!~16 mi

Week 4 is a planned recovery week (reduced volume). Weeks 11–12 are the taper. Don't skip recovery or taper — they're when your body absorbs the fitness you've built.

The Long Run: Your Most Important Workout

Your weekly long run builds the endurance foundation for 13.1 miles. Key principles:

Fueling and Hydration

The half marathon is the first distance where mid-race fueling meaningfully affects performance:

Before the Race

Eat a familiar, carb-heavy meal 2–3 hours before the start. Classic choices: oatmeal with banana, toast with peanut butter and honey, or a bagel with jam. Avoid high-fiber and high-fat foods. Drink 16–20 oz of water 2 hours before, then sip as needed.

During the Race

After the Race

Eat a meal with protein and carbs within 60 minutes. Chocolate milk is a popular recovery drink for good reason — it has the right ratio of carbs to protein. Continue hydrating throughout the day.

Pacing Your Half Marathon

The half marathon rewards disciplined, even pacing. The biggest mistake is going out too fast in the first 3 miles.

Use the splits calculator to generate your mile-by-mile pacing plan, and the training pace calculator to know your exact goal pace from a recent race.

Common Half Marathon Mistakes

1. Going Out Too Fast

Race-day adrenaline and the crowd will push you to run your first mile faster than planned. Resist it. Every second you "save" in mile 1 costs you 5–10 seconds in the final miles. Start conservatively.

2. Not Practicing Fueling

Trying a new gel or sports drink on race day is a recipe for stomach problems. Use your long runs to test exactly what you'll eat and drink during the race — same brand, same timing, same amount.

3. Skipping Recovery Weeks

Week 4 and the Weeks 11–12 taper aren't wasted time. They're when your body absorbs the training stress and gets stronger. Runners who skip recovery weeks are more likely to arrive at the start line fatigued or injured.

4. Running Long Runs Too Fast

Your long run pace should feel genuinely easy — 60–90 seconds per mile slower than race pace. If you're racing your long runs, you'll be too tired for your quality workouts and too worn down for race day.

Sample Week: What Training Looks Like

Here's an example of Week 6:

Day Activity
MondayRest or 30 min walk
Tuesday4 mi easy run
WednesdayWarm-up 10 min → 30 min tempo → Cool-down 10 min
Thursday4 mi easy run
FridayRest or cross-train
Saturday4 mi easy run
Sunday10 mi long run at easy pace (practice fueling at mile 5)

After the Half Marathon: What's Next?

Related Tools & Charts

Half Marathon Training FAQ

How long does it take to train for a half marathon?

12 weeks is standard if you can already run 6+ miles. If you're starting from a 5K base, plan 16–20 weeks — build to 10K first, then transition to this plan. Experienced runners running 25+ miles per week can use a 10-week plan.

Do I need to run 13.1 miles before race day?

No. Your longest training run is 12 miles. The combination of tapering (which freshens your body) and race-day adrenaline covers the remaining 1.1 miles. Running the full distance in training adds injury risk without meaningful fitness benefit.

What's a good goal time for my first half marathon?

Take your 10K time and multiply by 2.22. A 50:00 10K predicts roughly a 1:51 half marathon. Use the race time predictor for a more precise estimate. For your first half, aim for even pacing and a strong finish rather than a specific time.

Do I need energy gels for a half marathon?

Most runners benefit from 1–2 gels during a half marathon (at miles 5 and 9). Your body's glycogen stores are sufficient for roughly 90 minutes of running; after that, supplemental carbohydrates help maintain pace. Practice with gels in training to test tolerance.

How many days a week should I run?

4–5 days is optimal for most half marathon runners. Three days is often too little to build sufficient endurance, while 6+ can lead to overtraining for non-elite runners. Quality matters more than quantity — every run should have a purpose.

Should I run the day before the race?

A short, easy 2–3 mile shakeout run the day before can loosen your legs and calm pre-race nerves. Keep it very easy — jogging pace with a few 15-second strides. Some runners prefer complete rest. Do whatever you've done before long runs in training.

Disclaimer: This training plan is designed for healthy adults who can run 6+ miles comfortably. If you have any health concerns, consult a doctor before starting this program. This content is for informational purposes only and not a substitute for professional coaching advice.