Run training that adapts based on the running you do
Most running plans break when life happens. kaizen adapts to the running you actually do, continuously updating your training so you keep progressing toward your goal.
This launch means a lot to me because I’ve been building versions of this idea for almost 10 years.
It started with my own experience as a runner. I ran my first marathon at 17 and followed the kinds of plans most runners follow, but I kept running into the same problem: they only really worked if life went perfectly. Miss a few sessions, get a week wrong, and the whole thing could start to feel off track.
Over time, I became more interested in what actually helps someone improve in the real world. Turns out consistency is the primary determinant, closely followed by the ability to gradually increase training load. So I developed a system that ingested all my recent running history (relative to my past races and training) to understand how fit I was today, and work out how much I'd need to run each week to achieve my goal.
That system changed my own running completely. I went from a 3:24 marathon to 2:28 and became the top-ranked U23 marathoner in the UK. But more importantly, running stopped feeling like a cycle of falling behind and starting over. It became sustainable and enjoyable.
That’s where kaizen came from.
Really excited to finally share it here, and grateful to everyone who’s helped get it to this point.
About kaizen on Product Hunt
“Run training that adapts based on the running you do”
kaizen launched on Product Hunt on April 20th, 2026 and earned 217 upvotes and 21 comments, placing #4 on the daily leaderboard. Most running plans break when life happens. kaizen adapts to the running you actually do, continuously updating your training so you keep progressing toward your goal.
On the analytics side, kaizen competes within Health & Fitness, Running and Pitch Berlin — topics that collectively have 83k followers on Product Hunt. The dashboard above tracks how kaizen performed against the three products that launched closest to it on the same day.
Who hunted kaizen?
kaizen was hunted by Rajiv Ayyangar. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
For a complete overview of kaizen including community comment highlights and product details, visit the product overview.
Rajiv Ayyangar
Hey Product Hunt — Josh here, founder of kaizen.
This launch means a lot to me because I’ve been building versions of this idea for almost 10 years.
It started with my own experience as a runner. I ran my first marathon at 17 and followed the kinds of plans most runners follow, but I kept running into the same problem: they only really worked if life went perfectly. Miss a few sessions, get a week wrong, and the whole thing could start to feel off track.
Over time, I became more interested in what actually helps someone improve in the real world. Turns out consistency is the primary determinant, closely followed by the ability to gradually increase training load. So I developed a system that ingested all my recent running history (relative to my past races and training) to understand how fit I was today, and work out how much I'd need to run each week to achieve my goal.
That system changed my own running completely. I went from a 3:24 marathon to 2:28 and became the top-ranked U23 marathoner in the UK. But more importantly, running stopped feeling like a cycle of falling behind and starting over. It became sustainable and enjoyable.
That’s where kaizen came from.
Really excited to finally share it here, and grateful to everyone who’s helped get it to this point.