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

Twelve weeks from a base of three runs a week and a 4 to 5 mile long run. Sixteen if you are newer to running. From nothing at all, allow five to six months including a base phase.

How far should my longest run be?

10 to 11 miles. There is no need to cover 13.1 in training, and doing so adds recovery cost without much benefit.

How many days a week should I run?

Three is enough for a first half. Four is better if your schedule allows it, because the extra easy run adds aerobic volume at almost no cost.

What is a good first half marathon time?

Anything you finish feeling strong. For context, the median half marathon finish is somewhere around 2:05 for men and 2:20 for women, but a first half is about execution rather than a number.

Train for

Training for your first half marathon

The half marathon is the best distance in running. Long enough to demand real training, short enough that the block does not consume your life, and forgiving enough that a mistake on the day costs you minutes rather than the race.

Where you should be starting from

Running three times a week. Consistently, for at least six weeks.
A 5K under your belt. Or at least the ability to run 5K continuously without stopping.
A long run of 4 to 5 miles. Roughly 6 to 8km. This is the seed the block grows from.
Twelve weeks. From this base, twelve is comfortable. Sixteen if you are starting from less.

The twelve weeks

1
Weeks 1 to 4: build the long run
Three or four runs a week, nearly all easy. The long run climbs from 5 to 8 miles, adding about a mile a week with a down week after the third. Add strides twice a week: 6 x 20 seconds fast at the end of an easy run. They cost nothing and keep your legs from forgetting how to turn over.
2
Weeks 5 to 9: add one quality session
One session a week becomes structured. Start with 3 x 6 minutes at a comfortably hard effort and build toward 20 to 25 minutes continuous. The long run reaches 10 to 11 miles. This is the phase that makes race day feel manageable.
3
Weeks 10 to 11: the sharpest point
Longest run of the block, 11 to 12 miles, about two and a half weeks out. One session at goal half pace, roughly 3 x 2 miles, so you know what it feels like.
4
Week 12: taper
Volume drops by about half. Keep one short, sharp session early in the week. Two easy days before the race. Do not run 10 miles the weekend before because you feel fresh.

How far the long run needs to go

You do not need to run 13.1 miles in training. Getting to 10 or 11 is plenty, and the last two miles on race day come from adrenaline, taper freshness, and the crowd.

This is one of the ways the half is kinder than the marathon. The gap between your longest training run and the race distance is small enough that it never becomes frightening.

Pacing the first one

Take your recent 5K pace and add about 45 to 60 seconds per mile. That is a realistic first half marathon pace. If your 5K is 27:00, which is 8:42 per mile, aim for about 9:30 to 9:45.

Run the first three miles at that pace or slightly slower, even though it will feel far too easy. The half punishes an early surge less brutally than the marathon does, but it still punishes it, and the last 5K is where the race actually happens.

Frequently asked

How long does it take to train for a half marathon?: Twelve weeks from a base of three runs a week and a 4 to 5 mile long run. Sixteen if you are newer to running. From nothing at all, allow five to six months including a base phase.
How far should my longest run be?: 10 to 11 miles. There is no need to cover 13.1 in training, and doing so adds recovery cost without much benefit.
How many days a week should I run?: Three is enough for a first half. Four is better if your schedule allows it, because the extra easy run adds aerobic volume at almost no cost.
What is a good first half marathon time?: Anything you finish feeling strong. For context, the median half marathon finish is somewhere around 2:05 for men and 2:20 for women, but a first half is about execution rather than a number.

Your block, written

Put a date on it and Shed builds the weeks.

Shed takes your goal, your race date, and the days you can actually run, then writes every session between here and the start line. It reads each run off your Apple Watch the same day and moves what needs moving. No spreadsheet, no guessing at paces.

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