12-Week Half Marathon Training Plan (Beginner to Sub-2:00)

A half marathon training plan takes about 12 weeks and needs just three to four runs a week: one long run that builds to 11-12 miles, one faster tempo or interval session, and one or two easy recovery runs. Keep roughly 80% of your weekly mileage easy, raise your total distance no more than 10% each week, then taper hard for the final two weeks. The plan below assumes you can already run about 3 miles without stopping and takes you to the start line of a 13.1-mile race ready to run, not just survive.

Who This Plan Is For and What Base You Need

Start this plan with a base of roughly 3 miles, or the ability to run for 30 continuous minutes. If you cannot run for 20 minutes yet, spend three or four weeks building that first with a walk-run approach before Week 1, or work through a 5K training plan and a 10K training plan so 13.1 miles is a step up rather than a leap. Runners coming off a spring race can jump straight in. Complete beginners should stretch the schedule to 16 weeks by repeating Weeks 1-2 and 5-6, which keeps the long-run jumps gentle and protects your shins, knees, and Achilles from a sudden spike in load.

Your fitness comes from consistency, not heroics. Three well-placed runs a week done for 12 straight weeks beats five runs a week that end in an injury by Week 6.

The 12-Week Half Marathon Training Plan

Every week has the same shape: one long run (the priority), one quality session (tempo or intervals), and one or two easy runs. Distances are in miles. “Easy” means a conversational pace where you can talk in full sentences; “tempo” means comfortably hard, the effort you could hold for about an hour. Cross-training (XT) is optional cycling, swimming, or the elliptical — active recovery, not another hard day.

Week	Phase	Mon	Tue (Quality)	Thu (Easy)	Sat (Long Run)	Weekly Total
1	Base	Rest/XT	3 easy	3 easy	4	10
2	Base	Rest/XT	3 easy	3 easy	5	11
3	Base	Rest/XT	4 with 3×3 min tempo	3 easy	6	13
4	Base	Rest/XT	4 easy	3 easy	5 (cutback)	12
5	Build	Rest/XT	4 with 4×3 min tempo	4 easy	7	15
6	Build	Rest/XT	5 with 5×400m intervals	4 easy	8	17
7	Build	Rest/XT	5 with 20 min tempo	4 easy	9	18
8	Build	Rest/XT	5 with 6×400m intervals	4 easy	7 (cutback)	16
9	Peak	Rest/XT	6 with 25 min tempo	4 easy	10	20
10	Peak	Rest/XT	6 with 5×800m intervals	5 easy	11-12	22-23
11	Taper	Rest/XT	5 with 15 min tempo	4 easy	8	17
12	Race	Rest/XT	3 easy + 4 strides	2 easy shakeout	Race: 13.1	~18

Move days to fit your life, but keep at least one easy or rest day between the quality session and the long run so you arrive at each fresh. If a week feels flat, repeat it rather than pushing on — the plan bends without breaking.

The Three Phases: Base, Build, Peak, and Taper

Base (Weeks 1-4) grows your aerobic engine with mostly easy running. Resist the urge to run these fast. This is where you build the capillaries and mitochondria that let you burn fuel efficiently for over two hours, and it is best done at an easy zone 2 running effort you can hold a conversation through.

Build (Weeks 5-8) adds intensity. Your long run climbs toward double digits while the quality day sharpens speed with intervals and tempo runs. This is where goal pace starts to feel repeatable instead of frightening.

Peak (Weeks 9-10) carries your highest mileage and longest run — the 11-12 mile effort that proves to your body and your head that 13.1 is within reach.

Taper (Weeks 11-12) cuts volume so accumulated fatigue drains away and your muscles fully repair. You keep a little intensity to stay sharp, but total mileage falls about 30% in Week 11 and more than half in race week.

Long Run Progression: Building to 11-12 Miles

The long run is the backbone of the plan. It starts at 4 miles and climbs roughly a mile a week, with a cutback (easier) week every third or fourth week so your body absorbs the work instead of breaking down. Run it slow — 60 to 90 seconds per mile slower than goal race pace — because its job is endurance, not speed.

Two rules protect you here. First, never let the long run become more than about 40% of your weekly total, which the plan above respects. Second, cap the longest run at 11-12 miles; the final mile or two on race day comes free from your taper, the crowd, and adrenaline. Practise fueling on any run over 75 minutes, taking a gel or 30-60 grams of carbohydrate per hour and sipping water, so race-day nutrition is rehearsed rather than a gamble.

Tempo and Interval Days: Where Race Pace Is Built

One quality session a week turns endurance into speed. Alternate two types across the plan:

• Tempo runs teach your body to clear lactate at a faster pace. After a mile warm-up, hold a comfortably hard effort — around your current 10K-to-half pace — for 15 to 25 minutes, then cool down. If structured tempo bores you, unstructured fartlek training surges deliver the same stimulus by feel.
• Intervals (like 400m and 800m repeats with jog recovery) sharpen your top-end and running economy so goal pace feels easier. These short, faster reps are the core of most interval running workouts, and they are where you learn to hold form when fatigue sets in.

Do quality work on fresh legs, never the day after a long run. If you want to get quicker overall, pair these sessions with the drills in our guide on how to run faster.

Form, Cadence, and Injury Prevention

Most half marathon injuries come from doing too much too soon, not from bad luck. The 10% rule — never raising weekly mileage more than about 10% — is your first defence. Easy days kept genuinely easy are the second: if every run is moderately hard, you never recover, and the small aches become stress fractures.

Efficient mechanics help too. Aim for a quick, light turnover; nudging your running cadence toward 170-180 steps per minute shortens your stride and reduces the braking force that pounds your knees. Land with your foot under your hips rather than reaching out in front. If contact feels heavy or your knees ache, our guide to proper running form walks through the posture and foot-strike cues that lighten each step. Add two short strength sessions a week — squats, lunges, calf raises, single-leg work — to bulletproof the tendons that take the most load over 13.1 miles.

Race-Day Pacing and the Final Week

The most common half marathon mistake is starting too fast. Adrenaline makes goal pace feel easy for the first two miles, and runners who bank time early almost always pay it back with interest after mile 9. The smarter play is an even or slightly negative split: run the first 5K a few seconds per mile slower than goal pace, settle in through halfway, then, if you feel strong, press the final 5K.

Do the math before the gun. To break 2:00 you need about 9:09 per mile; a 2:15 finish is roughly 10:18 per mile; 2:30 is about 11:26. Write your target on your hand or set your watch to a pace alert. In the final week, trust the taper — the nervous energy from running less is normal and means it is working. Eat familiar carbohydrate-rich meals for two days, hydrate steadily, lay out your kit the night before, and arrive early enough for an unhurried warm-up. For a deeper dive on structure, mileage, and periodisation across every distance, see our full running training plan guide.

What to Do After Your Half Marathon

Cross the line, then recover with intent: walk to loosen up, refuel within an hour, and take at least a few easy or rest days before running again. Once you have the 13.1 habit, the natural next goal is 26.2 — and the base you just built transfers directly into a marathon training plan for beginners. Whether you chase a faster half or step up to the full, the same principles hold: run easy most of the time, add distance patiently, and respect the taper.