How To Train To Run A Half Marathon | Finish Strong

A half marathon sits in a sweet spot: it feels like a real event, yet you don’t need to train like a pro. What works is simple. Run often. Keep most runs easy. Add one longer run each week. Let your body adapt week by week.

Below you’ll get a clear training pattern, pacing cues that stop you from running every day like it’s a race, fueling basics for long runs, and a race-week plan that keeps your legs fresh.

Pick A starting point you can repeat

Training plans fail when they start above your current weekly routine. Start from what you can do right now, then build.

Baseline check

• New to running: start with run-walk sessions, three days per week.
• Can jog 20 minutes easy: start with three short runs plus one longer walk-run.
• Can run 5K: start a structured half marathon block.

If you’re coming back after injury, or you have a heart, lung, or joint condition, talk with a clinician before you ramp up.

How To Train To Run A Half Marathon in 12 weeks

Most first-timers do well with a 12-week block once they can run or run-walk three days per week. If you’re starting from zero, spend 4–8 weeks building the habit first, then begin the block.

What a week should look like

Think in patterns, not perfect days. Aim for four training days each week:

• Two easy runs for aerobic fitness.
• One long run for endurance and fueling practice.
• One quality day with strides, short hills, or a tempo block.

Add one low-impact session if you like (bike, swim, row, brisk walking). Keep it easy enough that your next run still feels good.

How easy runs should feel

Easy means you can speak in full sentences. If your breathing is sharp or you can only get out a few words, slow down. Most training miles should sit in this easy zone.

Set effort levels that keep you consistent

Many runners go too hard on easy days, then pay for it on the long run. Use these simple effort anchors:

• Easy: talkable, calm breathing.
• Steady: controlled, short phrases.
• Hard: short bursts only, full recovery between repeats.

If your watch pace swings because of hills or heat, trust feel first and let the numbers follow.

Build the long run without getting wrecked

The long run is the backbone of half marathon prep. It builds endurance, teaches pacing patience, and gives you a weekly chance to practice fueling.

Long run rules that keep progress steady

• Keep the pace easy for most of the plan.
• Finish feeling worked, not broken. If you’re limping after, it was too much.
• Practice drinking and carbs on runs longer than 75–90 minutes.

Later in the plan, add small steady segments inside the long run, like 10 minutes a bit quicker, then back to easy. This adds fitness without turning the run into a time trial.

Add speed work that fits a first half marathon

You don’t need brutal track sessions. You need a little faster running that stays controlled and leaves you ready to train again two days later.

Pick one option each week

• Strides: 4–8 × 15–20 seconds quick and relaxed, full recovery.
• Short hills: 4–8 × 20–40 seconds strong effort, walk down.
• Tempo block: 2 × 8–12 minutes steady with 3 minutes easy between.

Strength work that keeps runners running

Two short sessions per week can make running feel smoother, especially as mileage climbs. Keep it simple and repeatable.

Easy strength menu

• Split squats or step-ups
• Romanian deadlifts or hip hinges
• Calf raises
• Side planks or band walks

Leave a couple reps in the tank. You want to feel ready for your next run.

12-week half marathon outline

This table shows one way to progress the long run and keep weeks balanced. Move days around as needed, yet keep the pattern: easy runs, one quality session, one long run.

Week	Long run	Main focus
1	5 miles	Easy pace habit, add strides
2	6 miles	Easy miles, light hills
3	7 miles	Steady breathing on easy runs
4	5 miles	Cutback week, extra sleep
5	8 miles	First tempo block (short)
6	9 miles	Fuel practice on long run
7	10 miles	Long run patience, easy pacing
8	7 miles	Cutback week, keep strides
9	11 miles	Add steady segment late
10	12 miles	Dress rehearsal: shoes, gels
11	8 miles	Taper starts, legs feel fresh
12	Race week	Short easy runs, race plan

Fuel and hydration basics for long runs

Your stomach is part of training. Practice during long runs so race day isn’t a surprise. The ACSM position stand on exercise and fluid replacement explains goals like starting workouts well-hydrated and drinking during longer efforts.

Drink plan that stays simple

For many runners, water is fine on shorter runs. On long runs, especially in heat, a sports drink or water plus electrolytes can feel better. Use thirst as a guide, and on a few long runs check body weight before and after. If you’re down more than about 2% body weight, plan a bit more fluid next time.

Carbs during the run

On runs longer than 75–90 minutes, bring carbs. A common starting point is 20–30 grams every 30–40 minutes, then adjust based on gut comfort. Test the exact gels or chews you plan to use on race day.

Reduce injury risk with a few habits

Most running aches show up when the jump in load is too steep or easy days get pushed too hard. Keep volume growth gradual, and guard your easy pace like it’s part of the workout.

The American Academy of Orthopaedic Surgeons shares solid reminders in its tips for a safe running program, including building up slowly and choosing footwear that matches your needs.

Warning signs worth respecting

• Pain that changes your stride
• Pain that gets worse as you run
• Swelling, heat, or sharp pain in one spot
• Soreness that doesn’t fade after two easy days

If you hit one of those, swap running for low-impact cardio for a few days, then return with shorter easy runs. If pain sticks around or sharpens, get checked by a clinician.

Effort and pacing cheat sheet

Use this table on days when you’re unsure how hard to push. It’s built around feel, since watches and apps can drift.

Situation	What it often means	What to do next
Easy run feels hard	You’re tired, stressed, or under-fueled	Slow down, shorten the run, eat well after
Long run legs feel heavy early	Too fast at the start	Ease off for 10 minutes, settle into talk pace
Side stitch shows up	Breathing rhythm off, or drink timing	Slow down, exhale hard, sip smaller
Stomach sloshing	Too much fluid at once	Sip smaller amounts more often
Tempo pace fades fast	Going out too hard	Back off a notch and finish steady
Shin pain builds	Load jump, hard surfaces, worn shoes	Cut volume, use softer routes, get shoes checked
Calves tight every run	Hills, weak calves, or new shoes	Add calf raises, reduce hills for a week

Race week: taper without feeling flat

Taper means less volume, not zero running. Keep short easy runs so your legs stay loose. Keep one brief session with a few strides so pace doesn’t feel strange.

Simple race-week layout

• Two easy runs: 20–35 minutes
• One short shakeout: 10–15 minutes, optional
• Rest days: more than you think you need

Keep meals familiar. A slightly higher carb intake the day before can help you top off energy stores. Drink to thirst and don’t force gallons of water.

Race day plan you can follow under stress

Race day is mostly patience. Start too fast and the last 5K feels endless. Start controlled and you’ll pass people late.

Three simple cues

• First 3 miles: calm pace, relaxed shoulders.
• Middle miles: steady rhythm, fuel on schedule.
• Last 5K: lift effort gradually, quick steps, tall posture.

After the finish: recover and build from it

Walk for 10–15 minutes, drink to thirst, and eat something with carbs and protein. The next day, a gentle walk can loosen things up.

Give yourself at least a week of very easy running before you chase a new goal. Your fitness stays. Your tissues need time.

If you’re planning your first half marathon, also check the CDC adult activity guidelines to keep running and strength work balanced week to week. If you want a printable schedule, the NHS shares half-marathon plans like this NHS half marathon training plan PDF that you can adapt to your calendar.