Miles Half marathon
The Best Half Marathon Training Apps
The half marathon is where a lot of runners first want a real plan. A 5K you can wing. 21.1 km, not really. Most plans run 10 to 16 weeks, and the hard part isn't any single session. It's getting through three months of work trips, colds, bad sleep and birthday dinners without either skipping the long runs or cramming them.
So the useful question about a half marathon app is how it handles a bad week.
Comparison
| App | Price | Plan style | Good for | Watch out for |
|---|---|---|---|---|
 Runna |
$19.99/mo or $119.99/yr (US) | Coach-built, adapts to performance | Time goals, Garmin and Apple Watch users | Can be aggressive by default |
 Miles: AI Running Coach |
Free; Pro $14.99/mo or $99.99/yr (US) | Reflows around missed runs, live pace cues | iPhone and Apple Watch runners with busy weeks | iPhone only for now |
 Garmin Coach |
Free with a Garmin | Adaptive targets | Garmin owners | Needs Garmin hardware |
 Nike Run Club |
Free | Fixed plan, guided runs | A first half on no budget | No pace guidance, which can lead to injury |
 TrainAsONE |
Free tier; £99.99/yr (UK) | ML plan, adjusts for weather and missed runs | Data-minded runners | Unusual plans, dated app |
 Hal Higdon plans |
Free online; app is paid | Classic fixed plans | Proven structure | Not personal |
Runna
The most polished half marathon app. Pick your race, give it a recent time, and it builds a plan with paces for every session. Workouts go to Apple Watch, Garmin, COROS or Fitbit. If you're chasing a specific time and train off a watch, it's hard to beat.
The common complaint is that the default intensity is high. Users on Reddit describe getting injured on a plan that assumed more fitness than they had. Be honest about your recent times, and turn the intensity down if in doubt.
Miles: AI Running Coach
Miles builds a half marathon plan from where you are now and reflows it when you miss runs, rather than leaving a hole or doubling up. That's the part we care most about. During runs it gives live audio pace cues, which is especially useful for long runs, where most people start too fast and fade. After each run you see planned against actual, plus training load and readiness, so you know whether to push or back off.
It runs on iPhone and Apple Watch, syncs to Strava, and works with COROS. Pro is $99.99 a year or $14.99 a month. A 12-week block paid monthly costs about $45.
Nike Run Club
Free, and good enough for a lot of first-time half marathoners. The guided runs make long runs less lonely. Its biggest gap is pace guidance: nothing tells you when you're running too fast, which can lead to injury. The plan also doesn't rebuild if life gets in the way, so you'll need to make your own calls on missed weeks.
Garmin Coach
If you own a Garmin, try this first. It's free and adjusts targets from your watch data.
It's tied to Garmin hardware and fairly conservative about how much it changes week to week. Check which race distances your watch supports.
TrainAsONE
Adapts hard and factors in the weather. Its long runs can be shorter than traditional plans. That's deliberate, but it surprises people.
How to choose
First half, just want to finish: NRC, or a free Hal Higdon novice plan, is plenty.
Chasing a time: Runna or Miles. Both set paces from your current fitness. Runna if you run off a Garmin or you're on Android. Miles if you're on iPhone or Apple Watch and want live pace coaching for less.
Life keeps getting in the way: pick something that actually rebuilds the plan. Runna, Miles and TrainAsONE all do. NRC doesn't.
What a good half marathon plan includes
Whatever app you pick, check the plan has these:
One long run a week. The peak long run depends on your level. Beginners top out around 18 km, intermediate runners around 21 km, advanced runners at 22 km and elite runners at 24 km. A first-timer doesn't need to run the full distance before race day.
Mostly easy running. Most of your weekly distance should be at a pace where you could talk. If every run feels hard, the plan or your pacing is off.
One quality session a week. A tempo run or intervals. Beginners can start with strides and build up.
Gradual build. Weekly distance should rise in small steps, with an easier week every three or four weeks.
A taper. One to two weeks of reduced volume before race day, keeping a little intensity so your legs stay sharp.
Common half marathon mistakes
- Racing the long runs. Long runs are meant to be easy. Save the effort for race day.
- Making up missed runs. If you miss Tuesday, don't run it on Wednesday as well as Wednesday's run. Move on, or let the plan adjust.
- Going out too fast on race day. The first 5 km will feel easy. That's the trap. Run them at goal pace or a touch slower.
- New shoes on race day. Run in them at least a few times first, including one long run.
Try Miles on iPhone
A 5K to marathon plan built from your current fitness, reflowed when runs get missed, with live audio pace cues while you run. Free to download.
