Half Marathon Training Plan: 12 Weeks to Race Day

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This 12-week plan takes you from 12–15 miles per week to a half marathon finish. You’ll run 3–4 days per week, peak at 10–12 miles on your longest run, and taper in week 12. It works best if you’re already running at least 10 miles weekly; if you’re starting from scratch, build 6–8 weeks of easy running first.

The 12-Week Structure

The plan splits into three 4-week blocks with a different focus each phase.

Weeks 1–4 (Base): Easy runs only. Mileage climbs gradually to condition tendons and joints before any intensity is added. Most overuse injuries happen when runners add speed before their connective tissue is ready.

Weeks 5–8 (Build): Tempo runs enter the rotation. Long runs stretch to 8–9 miles. Weekly volume peaks around 20–25 miles.

Weeks 9–11 (Sharpen): One speed session per week. Long run peaks at 10–12 miles in week 11. You won’t run the full 13.1 in training—that’s intentional. The race itself provides the final stimulus.

Week 12 (Taper): Cut volume 40–50%. Two or three short easy runs keep your legs moving without digging into recovery.

Weekly mileage targets

• Weeks 1–2: 12–15 miles total (3 runs)
• Weeks 3–4: 15–18 miles total (3–4 runs)
• Weeks 5–6: 18–22 miles total (4 runs)
• Weeks 7–8: 20–25 miles total (4 runs)
• Weeks 9–10: 20–24 miles total (4 runs)
• Week 11: 18–22 miles total (4 runs, peak long run)
• Week 12: 8–12 miles total (2–3 easy runs)

The Four Weekly Workout Types

Easy runs (60–70% max heart rate)

These make up roughly 80% of your weekly volume. The test: you can speak a full sentence without gasping. Run 3–5 miles at this effort on your base days. Going faster feels productive but slows recovery and raises injury risk—resist it.

Long runs (70–80% max heart rate)

Once per week, add 0.5–1 mile every 1–2 weeks. Start at 4–5 miles in week 1, hit 10–12 miles in week 11. Pace these 30–60 seconds per mile slower than your goal race pace. Long runs train fat metabolism and build the mental stamina to hold form when tired.

Tempo runs (85–90% max heart rate)

Start these in week 5. Structure: 10 minutes easy, then 15–20 minutes at a pace where you can manage only 3–4 words at a time, then 5 minutes easy. One session every 7–10 days is enough. Tempo work raises your lactate threshold—the pace at which fatigue accelerates—which is the single biggest predictor of half-marathon performance.

Speed work (90–95% max heart rate)

Add one interval session starting in week 7. Two formats that work well: 6 × 3-minute repeats at half-marathon pace with 90-second recovery jogs, or 8 × 400 meters at 5K pace with 200-meter jogs. If you’re new to structured running, skip this and add a second easy run instead—the long run and tempo work will carry you to the finish line.

The best training plan is the one you’ll actually follow—consistency beats perfection every time.

Pacing Strategy: Know Your Target

Use a recent 5K or 10K as your baseline. A rough conversion: half-marathon pace runs about 10–15 seconds per mile slower than 10K pace. No recent race? Run hard and steady for 20 minutes on a flat route, note your average pace, then subtract 30–45 seconds per mile. That’s your starting target.

Once you have that number, set your training zones:

• Easy runs: 60–90 seconds slower than race pace
• Long runs: 30–60 seconds slower than race pace
• Tempo runs: 10–15 seconds faster than race pace
• Speed work: 30–60 seconds faster than race pace

Strength and Recovery

Two 20–30 minute strength sessions per week reduce injury risk and improve running economy. No gym required.

Strength exercises (2 sessions per week)

• Single-leg squats or Bulgarian split squats: 3 sets of 8–10 per leg
• Calf raises: 3 sets of 12–15 reps
• Glute bridges or single-leg deadlifts: 3 sets of 10–12 per side
• Planks and side planks: 3 sets of 30–60 seconds
• Lateral band walks: 2 sets of 12–15 per direction

Do these on non-running days or after easy runs—never before a hard session. Strong glutes and core stabilizers reduce the lateral hip drop that causes IT band syndrome and knee pain.

Recovery priorities

• Sleep: 7–9 hours per night. Adaptation happens during sleep, not during the run.
• Post-run nutrition: Eat carbs and protein within 30 minutes of any run over 45 minutes. A banana with peanut butter or Greek yogurt with fruit works.
• Hydration on long runs: 4–8 ounces of sports drink every 15–20 minutes once you’re past 60 minutes.
• Foam rolling: 5–10 minutes on calves, quads, and IT band after runs.

See our guide on how to prevent common running injuries for more detail on staying healthy through the build phase.

Nutrition and Fueling

Target 50–55% of daily calories from carbohydrates and 1.2–1.6 grams of protein per kilogram of body weight. At 150 pounds (68 kg), that’s 80–110 grams of protein daily. Carbs fuel your runs; protein repairs the muscle damage that makes you stronger.

For runs under 60 minutes, eat 1–2 hours before and drink water. For long runs and tempo work, have a small carb-forward meal 2–3 hours out—oatmeal with berries, toast with honey, or a bagel with jam. Skip high-fiber and high-fat foods before hard efforts; they slow gastric emptying and cause GI distress mid-run.

On race day, consume 30–60 grams of carbs per hour via gels, sports drinks, or energy chews. Practice this on your long runs—your gut needs training too. Never try a new gel or drink on race morning.

Tapering: Week 12

Drop mileage 40–50% from week 11. Run 2–3 easy sessions of 2–4 miles each. Include 4–6 × 1-minute pickups at goal race pace in one of those runs to keep your legs sharp without adding fatigue.

Expect to feel sluggish or restless—that’s normal. Your body is storing glycogen and repairing tissue. A hard run now won’t improve your fitness; it will only increase injury risk. Keep it short, keep it easy, and sleep as much as you can.

Gear Essentials

Running shoes

Best for neutral runners: Brooks Ghost or ASICS Gel-Excite. Best for overpronators: ASICS Gel-Kayano or Brooks Adrenaline GTS. Get gait-analyzed at a specialty running store before you buy. Replace shoes every 300–500 miles—you’ll likely need a fresh pair before race day if you start with worn ones.

Watch or app

Best free option: Strava or Nike Run Club. Best for pacing features: Garmin Forerunner 45 or Apple Watch SE. A basic GPS watch runs $50–150 and is worth it for pace accuracy on tempo days.

Other helpful gear

• Moisture-wicking shirt and shorts (cotton holds sweat and causes chafing)
• Anti-chafe balm for runs over 8 miles
• Foam roller ($20–40)
• Compression socks (no proven speed benefit, but some runners find them aid recovery between sessions)

Frequently asked questions

Marcus Bell
Marcus is a cycling coach and hiker who plans routes down to the water stops.