THE FARTLEK BLOG

Guides from your coach

Clear guides about training plans, AI running coaches, and how to choose the support that actually fits your running: comparisons, tips, and news.

FEATUREDGuides22 Aug 2026 · 6 min read

Why ChatGPT forgets your training

The memory got better in June 2026. It still does not know what you ran last week. The reason is what a memory built for personal answers keeps, and what it leaves out.

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Guides5 min read

Can AI give useful input on your running?

The question is not whether an app can write you a better plan, but whether AI can say anything useful about the one you already have. What it sees, what it misses and where the line sits.

Comparisons5 min read

Can you talk to Runna?

Runna chat is customer support, not coaching. What you can ask, what the plan does instead, and what a coach who remembers six months back knows that the curves do not show.

News2 min read

Self coached: you plan, the coach reviews

A new mode in the app: you build your training weeks yourself in the calendar and the coach becomes an adviser. Entirely optional, everything else continues as before.

Guides6 min read

Running training with young kids: making the weeks work

The evening is the worst training window in a house with small children. How to build a week that survives broken sleep and a winter of daycare infections.

Guides6 min read

Half marathon training plan: under 2 hours

Sub-2 means 5:41 per kilometre. Here is what twelve weeks to get there looks like, and how to save the plan when life interferes.

Comparisons5 min read

Is Garmin Coach enough?

The free coach on your watch goes further than its reputation. How to tell where the template ends, and when paying for more is worth it.

Guides6 min read

Marathon training on three runs a week

A marathon does not require five runs a week. This is how far three will take you, and how to choose them.

Comparisons4 min read

How much does Runna cost? The full price picture in 2026

Runna costs about $17 per month or $110 per year. What do you get for the money, and what do the alternatives cost?

Comparisons5 min read

Free running coach apps: what you get, and where the limit is

Garmin Coach is included with the watch and Nike Run Club is completely free. What do you get, where is the limit, and when is paying worth it?

News2 min read

Coach Fartlek 2.0 is here

We rebuilt the app from the ground up. A new interface, a light theme and a start that puts you straight in the chat with the coach.

Comparisons8 min read

TrainAsONE alternative: a coach you talk to

TrainAsONE rebuilds your plan after every run — but you don't talk to it. Here's what it does well and how Coach Fartlek differs.

Comparisons8 min read

Athletica alternative: a running coach you talk to

Athletica is a science-heavy multisport platform — Coach Fartlek is a focused running coach you talk to that reaches out. Here is the difference.

Comparisons7 min read

Best AI running coach apps in 2026

There's no single best AI running coach — only the one that fits how you train. Here are the options that matter in 2026, compared honestly.

News1 min read

Coach Fartlek is now on iOS

It's finally here — Coach Fartlek is now available to download for iPhone on the App Store. The circle is complete.

Comparisons8 min read

Runna alternatives: what to know before you choose

Runna is popular for a reason — but not for everyone. A fair look at the alternatives and who each one suits.

Comparisons6 min read

ChatGPT as a running coach: how far does it get you?

ChatGPT is a good sounding board for one-off questions — but a different thing from a coach that follows you over time. Where is the line?

AI Coaching6 min read

The running app that adapts to your recovery

The difference between an app that shows your recovery and one that actually changes the plan based on HRV, resting heart rate, and sleep.

News1 min read

Coach Fartlek is now on Android

It's finally here — Coach Fartlek is now available to download for Android. iOS is coming soon.

AI Coaching5 min read

What makes Coach Fartlek different?

Coach Fartlek is not a static plan and not a generic chat. It is proactive, flexible, and gets more personal the more it gets to know you.

Guides7 min read

AI running coach comparison: what should you choose?

AI coaching ranges from generic chatbots to adaptive planning systems. These are the differences that matter for runners.

Put the guides into practice.

Coach Fartlek turns the advice into a plan that fits your week.

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