If an app tells you exactly what session you'll be doing 16 weeks from now, it's writing cheques that it cannot cash. The problem is simple: your body isn't predictable and neither is the future. If we could predict the future 16 weeks in advance, we would not be selling you training plans… 

Every run changes your physiology. You adapt, then recover,, or sometimes you don't. Stress at work, poor sleep, illness, travel, or even a couple of harder-than-expected sessions can completely change what the optimal workout is next week, let alone four months from now.

Most training apps don't account for this. Despite being marketed as "AI", many simply generate a fixed plan from the answers you give during onboarding and use some kind of ChatGPT generated post run feedback and call that “coaching”. Enter the same information, get the same plan. But no two runners respond to training in exactly the same way.

We even see this in identical twins. Research has shown that people with almost identical genetics, following the same training programme, still adapt differently. Previous training history, recovery, lifestyle and countless biological factors all influence how your body responds. The best coaches understand this, which is why they constantly adjust training instead of blindly following a schedule written months in advance.

That's exactly how The Running Algorithm works.

Rather than trying to predict the future, we only plan as far ahead as we can be confident about (though even 2 weeks is a bit of a stretch). After every run, we estimate your fatigue, learn how your body responds to different types of training, and use that information to decide what comes next. If you're adapting faster than expected, training progresses. If life gets in the way and you're carrying more fatigue, it backs off before you dig yourself into a hole or get hurt.

Just as importantly, we also know when not to change your plan. Updating after every session would make training chaotic. Never updating it would make it rigid. The challenge is finding the balance between stability and adaptation.

Your next run should be based on who you are today, not who a few lines of code guessed you'd be four months ago.

That's why The Running Algorithm doesn't try to predict your entire marathon block.

It learns from every run, adapts to every response, and builds your training one decision at a time.