Half Marathon Training Plan: A Complete 12-Week Guide for Your First 13.1

The half marathon is the fastest-growing race distance in the world, and for good reason. At 13.1 miles, it demands genuine endurance and structured training, but it does not require the months of high-mileage preparation that a full marathon does. It is the distance where recreational runners become real distance runners.

What Is a Half Marathon?

A half marathon is a road race covering 13.1 miles (21.1 kilometers), exactly half the distance of a full 26.2-mile marathon. It is long enough to require fueling strategy, pacing discipline, and dedicated long runs, but short enough that recovery takes days rather than weeks.

The half marathon sits in a physiological sweet spot. It is primarily an aerobic effort, meaning your training will focus on building endurance, improving lactate threshold, and developing the mental toughness to maintain pace for 90 minutes to 2.5 hours depending on your fitness level.

What Are the Prerequisites for Half Marathon Training?

Before starting a 12-week half marathon plan, you should meet these baselines:

Run 6-8 miles comfortably in a single outing
Run 15-20 miles per week consistently for at least a month
Have at least 6 months of regular running behind you
Be free of injury and able to handle increasing training loads

If you are not yet at this level, invest 8-12 weeks in building your base. Rushing into a half marathon plan without adequate preparation is a reliable path to injury, particularly in the knees, shins, and Achilles tendons.

12-Week Half Marathon Training Plan

This plan builds from a 20-mile weekly base to a peak of approximately 35 miles, with a taper in the final two weeks. It includes three key workout types: easy runs, tempo runs, and long runs. One day per week is designated for speed work or hill training.

Week	Mon	Tue	Wed	Thu	Fri	Sat	Sun
1	Rest	4 mi easy	5 mi with 15 min tempo	4 mi easy	Rest	7 mi long	Cross-train
2	Rest	4 mi easy	5 mi with 20 min tempo	4 mi easy	Rest	8 mi long	Cross-train
3	Rest	5 mi easy	6x400m intervals	4 mi easy	Rest	9 mi long	Cross-train
4	Rest	4 mi easy	5 mi with 20 min tempo	4 mi easy	Rest	7 mi long (recovery week)	Cross-train
5	Rest	5 mi easy	5x800m intervals	5 mi easy	Rest	10 mi long	Cross-train
6	Rest	5 mi easy	6 mi with 25 min tempo	5 mi easy	Rest	11 mi long	Cross-train
7	Rest	5 mi easy	4x1 mi intervals (2 min rest)	5 mi easy	Rest	10 mi long	Cross-train
8	Rest	5 mi easy	6 mi with 30 min tempo	4 mi easy	Rest	12 mi long	Cross-train
9	Rest	5 mi easy	5x1000m intervals	5 mi easy	Rest	11 mi long	Cross-train
10	Rest	5 mi easy	6 mi with 30 min tempo	5 mi easy	Rest	13 mi long	Cross-train
11	Rest	4 mi easy	4 mi with 20 min tempo	4 mi easy	Rest	10 mi long (taper starts)	Cross-train
12	Rest	3 mi easy	3 mi with 4x100m strides	Rest	2 mi shakeout	Race Day: Half Marathon	Rest

Week 4 is a deliberate recovery week with reduced long run distance. This allows your body to absorb the training from weeks 1-3 before the next build phase.

How Should Long Runs Progress Week by Week?

The long run is the most important workout in half marathon training. It builds the aerobic endurance, fat-burning capacity, and mental resilience needed to cover 13.1 miles on race day.

Week	Long Run Distance	Cumulative Longest Run
1	7 miles	7 miles
2	8 miles	8 miles
3	9 miles	9 miles
4	7 miles (recovery)	9 miles
5	10 miles	10 miles
6	11 miles	11 miles
7	10 miles	11 miles
8	12 miles	12 miles
9	11 miles	12 miles
10	13 miles	13 miles
11	10 miles (taper)	13 miles
12	Race: 13.1 miles	13.1 miles

Run long runs at an easy, conversational pace. They should feel comfortable for the first two-thirds and challenging only in the final miles. If you are struggling through the middle of your long run, you are running too fast.

Use long runs as an opportunity to practice your race day fueling, hydration, and gear. By race day, nothing should be new.

What Are the Key Workout Types?

Easy runs make up 70-80% of your weekly mileage. They build aerobic fitness without creating excessive fatigue. Your easy pace should allow you to speak in complete sentences. If you can only manage a few words, slow down.

Tempo runs train your body to sustain a moderately hard effort. Run them at a pace you could maintain for about one hour in a race, roughly 25-30 seconds per mile slower than your 10K pace. These runs improve your lactate threshold, which directly influences your half marathon pace.

Intervals develop VO2 max and running economy. Run 400m-1600m repeats at your 5K-10K pace with jogging recovery. These sessions are shorter and faster than race pace, building the aerobic ceiling that supports your half marathon effort.

Cross-training on Sundays maintains fitness while giving your legs a break from running impact. Cycling, swimming, elliptical, or brisk walking are all effective options.

When Should I Start Fueling During the Half Marathon?

Fueling during a half marathon becomes necessary for most runners when the effort exceeds 75-90 minutes, as the body’s glycogen stores begin to deplete beyond this point. Failing to fuel properly can cause a dramatic slowdown in the final miles, commonly known as “hitting the wall” or bonking.

Here is a practical fueling guide:

Before the race: Eat a carbohydrate-rich meal 2-3 hours before the start. Toast, oatmeal, or a bagel with peanut butter are common choices.
During the race (60-75 minutes in): Take your first gel or handful of energy chews with water.
Every 30-45 minutes after: Continue taking small amounts of carbohydrates. Most runners need 30-60 grams of carbohydrates per hour.
Hydration: Drink water at aid stations when thirsty. Do not over-drink. Approximately 4-6 ounces every 15-20 minutes is sufficient for most runners in moderate conditions.

Practice your fueling strategy during long training runs. Your stomach needs to adapt to processing food while running, and race day is not the time to experiment.

What Pace Should I Target Based on My Goal Time?

Goal Time	Pace per Mile	Pace per Kilometer	Finish Time
1:45	8:01	4:59	1:45:00
2:00	9:09	5:41	2:00:00
2:15	10:18	6:24	2:15:00
2:30	11:27	7:06	2:30:00

To determine a realistic goal, run a 10K race or time trial during weeks 4-6 of training. Multiply your 10K time by 2.22 for an approximate half marathon prediction. For example, a 55-minute 10K projects to a 2:02 half marathon.

PaceBoard helps you track your training paces across weeks so you can identify whether your fitness is trending toward your goal time or whether you need to adjust your target.

How Should I Taper for a Half Marathon?

Tapering is the planned reduction of training volume in the final 1-3 weeks before a race, allowing your body to fully recover and arrive at the starting line fresh. Skipping the taper is one of the most common mistakes among first-time half marathoners.

During the taper:

Week 11: Reduce total mileage by 25-30%. Keep one tempo run but shorten it. Long run drops to 10 miles.
Week 12 (race week): Reduce mileage by 50% or more. Run 2-3 short, easy runs with a few strides at race pace. Rest completely on Thursday and Friday before a Saturday or Sunday race.

You may feel sluggish or anxious during the taper. This is normal. Your body is restocking glycogen, repairing muscle tissue, and building fresh red blood cells. Trust the process.

What Is the Best Race Day Plan?

Morning of the race: Wake up 2.5-3 hours before start time. Eat your tested pre-race meal. Arrive 60 minutes early for parking, bag check, and restroom lines.

Warm-up: Jog 10 minutes at an easy pace and do 4-6 strides. This raises your heart rate and prepares your legs for race pace from the start.

First 3 miles: Run at goal pace or 5-10 seconds slower. The adrenaline of race day will tempt you to go out too fast. Resist this. Even splits or slight negative splits (running the second half faster) produce the best results.

Miles 4-9: Settle into your rhythm. Focus on relaxed form, steady breathing, and hitting your splits. Take your planned nutrition around mile 6-7.

Miles 10-13.1: This is where the race truly begins. Fatigue sets in, and your pace may start to drift. Maintain focus on form. Use PaceBoard post-race to review your splits and see where you held pace or faded.

After the finish: Walk for 10 minutes, hydrate, and eat within 30 minutes. Recovery runs can resume 3-5 days after the race, depending on how you feel.

FAQ

How long does it take to train for a half marathon? Most runners need 10-16 weeks to train for a half marathon. A 12-week plan works well for runners who can already run 6-8 miles comfortably. Complete beginners should first build a running base over 2-3 months before starting a half marathon plan.

What is a good half marathon time? A good half marathon time depends on experience. For beginners, finishing under 2:30 is a solid goal. Intermediate runners often target 1:45-2:15. Competitive recreational runners aim for sub-1:45. The average half marathon finish time in the United States is approximately 2:02.

Do I need to fuel during a half marathon? Yes, most runners benefit from fueling during a half marathon. For efforts over 75-90 minutes, consuming 30-60 grams of carbohydrates per hour from energy gels, chews, or sports drinks helps maintain blood sugar and delays fatigue. Practice your fueling strategy during training long runs.

How many miles a week for half marathon training? Most half marathon training plans peak at 25-40 miles per week. Beginners typically train 20-30 miles per week, while experienced runners may run 35-45 miles per week. The key is building gradually and including variety in your weekly runs.

Can a beginner run a half marathon? Yes, a beginner can run a half marathon with proper preparation. You should first be able to run 6-8 miles comfortably and have a base of 15-20 miles per week. From there, a 12-16 week training plan with gradual mileage increases will prepare you for 13.1 miles.