How to train for a half marathon (without giving up the gym)

Here's how to train for a half marathon in one paragraph: give yourself 10 to 16 weeks, run three to five times a week, make most of those runs easy, grow one long run toward 10 to 12 miles, add one quality session, keep lifting once or twice a week, and taper at the end. That's it. Everything below is the detail that makes it work.

The detail matters because most half marathon plans assume you do nothing else. You lift. You maybe have a Hyrox on the calendar. A running plan that ignores your squat day will happily schedule intervals for the morning after it. Whether you build the plan yourself from this guide or use a Runna alternative that includes lifting, the job is the same: one week, two goals, no collisions.

What a half marathon training plan actually needs

13.1 miles (21.1 km) is long enough that you can't fake it on gym fitness and short enough that you don't need to live in your running shoes. A good build has five ingredients:

1. ›Easy volume. Most of your weekly running, at a pace you could hold a conversation at.
2. ›A long run. One per week, growing gradually. This is the session that makes 13.1 miles feel normal.
3. ›One quality session. Tempo, intervals or fartlek. One, not three.
4. ›Strength work. One or two sessions a week, kept but not chased.
5. ›Recovery built in. A lighter week every three or four, and a taper at the end.

If you want those five ingredients already laid out week by week, that's what a half marathon program is for. If you'd rather understand the moving parts first, keep reading.

If you're coming up from shorter races, the logic is the same as 5k training, just stretched: more easy volume, a longer long run, and quality work that leans toward sustained efforts rather than short, sharp ones.

How long to train for a half marathon

It depends on where you're starting:

For reference, Hal Higdon's widely used Novice 1 half marathon plan is 12 weeks and assumes you can already run 3 miles, three to four times a week. That's a sensible baseline. If you're starting below it, add a block of easy running before the plan starts rather than squeezing the plan.

Shorter isn't braver. A rushed build mostly means the long run grows faster than your tendons do.

The weekly structure

A typical half marathon week, for someone who also lifts twice:

The rules behind it:

• ›Hard things apart. Quality run and heavy legs never on back-to-back days if you can avoid it.
• ›Heavy legs after the quality run, not before. The day after intervals is fine for lifting, because the intervals were done fresh. The day before the long run is not.
• ›The long run is a hard day. Treat it like one. Nothing heavy the day after.

Three runs a week will get you to the finish. Four or five gets you there faster and feeling better. Past that, for a hybrid athlete, the extra running usually costs more lifting quality than it's worth.

Keep lifting: 1–2 strength sessions a week

You don't have to choose between a half marathon and the gym. You have to choose which one leads for the next few months. During a half marathon build, running leads and lifting supports.

What that means in practice:

• ›Two sessions a week early in the build, one or two later. One lower-focused, one upper or full body.
• ›Keep the weights heavy-ish, cut the volume. Fewer sets, fewer reps, same quality. Three hard sets of a squat or deadlift variation, not eight.
• ›Don't chase PRs. Maintain and stay robust. Strength PRs can come after the race.
• ›Schedule around the runs. Lower body goes on an easy run day, away from both the quality session and the long run.

This isn't just about keeping your gains. A systematic review by Blagrove and colleagues (2018) found that adding strength training improved running economy by 2–8% in most of the studies that measured it, with body composition not negatively affected, and the authors suggest two to three sessions a week. So the gym is helping your half marathon, not competing with it. There's more on strength training for runners if you want the exercise selection.

And if you're worried the running will eat your muscle: an updated meta-analysis by Schumann et al. (2022) concluded that concurrent aerobic and strength training doesn't compromise hypertrophy or maximal strength, though explosive strength gains may be blunted, especially when both are done in the same session. Splitting runs and lifts across different days, or at least different ends of the day, handles most of that.

The quality session

One hard session a week is enough for most hybrid athletes. Rotate between three types:

• ›Tempo runs. 15 to 30 minutes at a "comfortably hard" effort, roughly the pace you could hold for an hour. This is the closest thing to half marathon specificity.
• ›Intervals. Repeats of 3 to 5 minutes at a harder effort, with easy jogging between. Builds the top end.
• ›Fartlek. Unstructured surges inside an easy run. Speed play (fartlek) is the gentlest way to introduce quality work, and the easiest to fit around a heavy lifting week.

Early in the build, keep quality short and controlled. In the last four to six weeks, shift toward longer efforts at or near goal pace.

Easy running: most of the plan

The quality session gets the attention. Easy running does most of the work.

Most runners run their easy days too fast and their hard days too slow. The result is medium everything: tired all the time, never fit enough to go genuinely fast. Easy means conversational. Full sentences, breathing under control, a pace that feels almost embarrassingly slow. If you train by heart rate, this is where zone 2 cardio lives, and it's where your aerobic engine gets built. Around three quarters or more of your weekly running should feel like this. That's coaching convention, not a law of physics, but it's a very good default.

For lifters, easy running has a second job: it's the running you can do without wrecking tomorrow's squat session.

The long run

The long run is the most important session in the plan. It builds endurance, gets your legs used to time on feet, and is where you rehearse race-day eating.

How to progress it:

• ›Start where you are. If your longest recent run is 4 miles, the first long run is 4 or 5 miles, not 8.
• ›Add about a mile most weeks, with a shorter long run every third or fourth week.
• ›Peak at 10 to 12 miles, two to three weeks before race day. You don't need to run 13.1 in training. Race-day adrenaline and a taper cover the rest.
• ›Run it easy. Most long runs should be conversational the whole way. Later in the build, you can finish the last 2 to 3 miles at goal pace.

Picking a goal pace

Goal pace should come from evidence, not hope. The average half marathon time tells you where most of the field finishes, which is useful context but not a target. Your own recent 5K is a far better predictor. Holding your result up against 5K time benchmarks also tells you whether you're starting from a strong speed base or a strong endurance base, and that changes which quality sessions deserve more of your week.

First half marathon and no recent race? Make the goal "finish feeling strong" and run the whole thing by effort.

Recovery weeks and the taper

Every third or fourth week, step back: cut running volume by roughly a quarter to a third, shorten the long run, keep the lifting light. You come out the other side fitter, not lazier.

Then taper. Tapering for a race means cutting volume while keeping some intensity, so you arrive fresh but not flat. A meta-analysis by Bosquet et al. (2007) found a two-week taper with volume cut by 41–60%, while keeping intensity and frequency, was the most effective approach across the studies it pooled. For a half marathon, many runners do fine with 7 to 14 days. In practice:

• ›Running: shorter runs, a few short race-pace efforts, same number of days.
• ›Lifting: last real lower-body session 7 to 10 days out. Light upper body or mobility after that.
• ›Long run: last proper one about two weeks out. The weekend before race week is shorter.

The same principles scale up. Strength training for marathoners follows the same logic with more running volume to manage and a longer taper, which is why lifting often drops to one session a week in the heaviest marathon weeks.

The fitness is built. The taper just lets you access it. Do not add a hard session in race week because you feel guilty.

Race day

Start slower than you want to. The first 2 to 3 miles should feel almost too easy. If you go out at goal pace plus excitement, you'll pay for it in the last 5K.

Nothing new on race day: not shoes, not breakfast, not a gel flavor you've never tried. Run the plan you rehearsed on your long runs.

Common mistakes

• ›Running every run at the same pace. Easy days get too hard, hard days aren't hard enough.
• ›Growing the long run too fast. Patience here is the whole plan.
• ›Starting from zero with ten weeks to go. A couch to half marathon in 12 weeks build is possible for some people, but it leaves no slack for a cold, a work trip or a grumpy Achilles.
• ›Heavy squats the day before the long run. You'll feel it at mile 7.
• ›Dropping lifting completely. Then wondering why you feel fragile by week 8.
• ›Going straight back to heavy legs after the race. Half marathon recovery is mostly a few days of easy movement, food and sleep, then light loads before heavy ones. If something hurts beyond normal post-race soreness, see a professional.
• ›Winging the fuel. Half marathon fueling doesn't need to be complicated, but it shouldn't be invented on race morning. Whatever you'll eat and drink on the day, try it on long runs first.
• ›Cramming missed sessions. Missed a run? Skip it and move on. Don't stack two quality days to catch up.

How exrsz handles this

exrsz builds a periodized half marathon plan from your race date, how many days you can train, your level and your equipment, with the running and lifting in the same plan so the quality run and the heavy legs day never end up as neighbors. It adapts each week to how your training actually went and reshuffles missed sessions instead of guilt-tripping you.

FAQ

How many weeks do I need to train for a half marathon?

Most runners who can already run about 3 miles comfortably use a 10 to 12 week plan. Complete beginners should allow 16 weeks or more, and experienced runners can get race-ready in 8 to 10.

How long should my longest training run be for a half marathon?

Most plans peak at 10 to 12 miles, two to three weeks before the race. You don't need to run the full 13.1 miles in training.

Can I lift weights while training for a half marathon?

Yes. Keep one or two strength sessions a week, reduce the volume, skip the PR attempts, and schedule heavy lower-body work away from your quality run and long run.

How many days a week should I run for a half marathon?

Three runs a week is enough to finish. Four or five gives you more aerobic fitness and usually a better race, as long as most of those runs are easy.

What should I do the week before a half marathon?

Cut running volume, keep a few short race-pace efforts, stop heavy lifting, sleep well, and change nothing about your shoes, breakfast or fueling.