Which AI coaching app to train for a marathon?
There is no best app in absolute terms. There is the best app for your profile: first marathon or time goal, running only or multisport, Garmin watch or not. Here are the four criteria that matter, then our view, profile by profile.
The 4 criteria that really matter
- Does the plan adapt to what you actually did, not just to what was planned?
- Does it tell you when you are overdoing it? Over 16 weeks of training, the first risk is injury, not a lack of volume.
- Can you ask it a question, like “my shin hurts, what do I do tomorrow?”
- Does it account for your other sports? Cycling, swimming and strength work tire you too.
| App | Who it suits | Adaptation | Chat with the coach | Multisport |
|---|---|---|---|---|
| UpGreg | Runners and multisport athletes, in 5 languages | After every session | Yes (Greg+) | Yes, one training load |
| Runna | Runners who want a structured plan, guided on the watch | AI adjustments | Feedback after each session | No (running, strength) |
| TrainAsONE | Data-driven runners | Every day, by algorithm | No | No |
| Athletica | Endurance athletes with a scientific bent | Based on load and fatigue | Yes | Yes |
| Garmin Coach | Garmin watch owners | Based on watch data | No | Running, cycling, triathlon |
Features checked on 1 October 2026 on the publishers' websites; they change quickly.
Our recommendation, profile by profile
- First marathon, running alone: UpGreg or Runna. UpGreg if you want someone to hold you back when you overdo it.
- Time goal, you love numbers: TrainAsONE or Athletica.
- You own a Garmin watch and have a small budget: start with Garmin Coach, which is free.
- You also ride, do triathlon or Hyrox: UpGreg or Athletica.
How many weeks to train for a marathon?
It depends on your starting level, not on a magic number. Greg's “First marathon” page gives the realistic duration for your level, as a level-by-duration table.
💬 The question you don't dare ask an app
An AI coach must also be able to say no.
Excerpt of a typical conversation with Greg in the app
Frequently asked questions
Can an AI coach replace a human coach for a marathon?
For writing and adapting the plan, yes for most amateur runners. For watching your stride or reassuring you on race day, a human remains irreplaceable.
Which app is the cheapest?
Nike Run Club and Garmin Coach are free. UpGreg has a free plan, Starter; recalculation after every session starts with the Greg plan, at €8/month.
Do you need a watch to use an AI coach?
No, but it is more accurate with one. UpGreg reads your sessions from Apple Health or Health Connect, or from your .FIT, .GPX and .TCX files.
« I'm not neutral, obviously. But if you only run and you love your Garmin watch, I'll tell you straight: Runna will suit you very well. If you want someone who tells you the truth about your finish time, I'm here. »