What we do

Most training plans are built for someone else: a generic runner with a perfect schedule and no life getting in the way. Real training never looks like that. You miss runs. Work blows up. A niggle in your calf makes you rethink the week.

Pheidi builds a plan around your life and adjusts as things change, so you can stop guessing and just run. Pick your race and distance, tell us your experience and your real availability, and you'll get a plan that makes sense, with the science behind every call if you want to see it.

Why I built Pheidi

In my twenties I ran a bunch of half marathons. No kids, no mortgage, nothing but time on my hands. The plans I downloaded off the internet worked great, mostly because my life had nothing in it that could knock them over.

Then, you know, life happened. Kids showed up. Work got heavier. Vacations, deadlines, somebody's sick day, all the normal stuff that eats your week when you're an adult. A static plan sitting in a spreadsheet has no idea any of that is going on. It just sits there, unchanged, judging you quietly while you fall behind it.

So I'd miss a run. The plan didn't care. I'd miss another. Still didn't care. Eventually I'd be standing at the start line telling myself I could make up the miles I never ran, which, spoiler, is not how running works. I got hurt more than once from it too. Not because I didn't care about training, but because I was quietly undertrained and nothing was around to tell me that was happening.

Then there was the logistics of it. Every single run had to get typed into a calendar by hand, checked against work meetings, explained to my wife so she'd know where I was and for how long. At some point, coordinating the training took more energy than the actual running. Which felt backwards, since running is supposed to be the easy part.

Here's the thing nobody tells you about getting older: your body starts sending you polite little memos that it would like you to move it more often, and your calendar responds with a firm no. It's a fun standoff. I don't want running to be my whole life, I've got kids and a job and a marriage I actually like, but I also can't just let those things quietly bury the thing that keeps me sane. That's the whole idea behind Pheidi. The plan should bend when your week does, no guilt trip, no bro science yelling at you about a broken streak. Life happens. The plan should just handle it.

I'm still running marathons. I just needed a plan that understood I have an actual life to run them around, so I built one.

Running changed my life, honestly. Nothing clears my head like it, especially on a cold, crisp morning on the trail, hearing the leaves crunch under my feet and nothing else. I built Pheidi so more people get to keep that in their life instead of losing it to a plan that just doesn't fit.

A quick word on AI. I use AI as a tool. It helps me write code faster and get through sports science research faster. But there is no AI quietly making your training decisions behind the scenes. Every plan Pheidi builds runs on hard coded logic based on published research and established coaching methodology, not a model guessing at what a good week looks like. I use AI to summarize papers and move faster as a developer, not to invent your plan for you. I don't want to spam you with AI slop. I want to build the best running plan app I possibly can. Behind Pheidi is just one person, me, John. A regular human who wants you to actually enjoy this and get your runs in.

John, founder of Pheidi

Build log

Pheidi is a one-person company, and I write about how it gets built. No marketing spin, just the real decisions and trade-offs behind the app.

What we stand for

We want you to feel confident and supported, like you've got a coach who actually knows your situation. That shapes everything:

  • Clarity over decoration. Every part of the app earns its place. If it doesn't help you understand or act, it's gone.
  • Confidence through precision. Consistent, considered, engineered, not decorated. The details are the point.
  • Respect for your time. Fast, scannable, minimal clicks. You check your plan and get on with your day.
  • Science you can trust. Our advice references published research and established coaching methods, and says so.

The runner behind the name

"Pheidi" comes from Pheidippides, the Greek courier tied to the very first marathon. You probably know the legend: he ran to Athens after the battle, shouted that the Greeks had won, and dropped dead.

That story is mostly myth. The real Pheidippides was a professional long-distance runner who covered roughly 150 miles to Sparta and back to ask for help before the battle, an ultramarathon of showing up when it counted. That's the spirit we named the app after: not the tragic collapse, but the endurance, the discipline, and the habit of showing up, one run at a time.

Want the full history, legend versus fact, the Battle of Marathon, and why a marathon is 26.2 miles? Read the story of Pheidippides and the first marathon.