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.
Interesting idea. How well does it adapt when someone’s schedule becomes inconsistent rather than just slightly off plan?
This hits a real pain most running plans assume perfect consistency which which just isn’t how life works.
If running is your primary sport, Kaizen is the way to go!
Balancing all the training for long distance running can become a constant puzzle with everything else going on in your life. I think Kaizen really helps simplifying training by making you focus on what matters - gradually increasing your total training load step-by-step.
The dynamic tracking of this training load really helped me see when I was at risk of overtraining. Am convinced this has spared me some overtraining injuries in the past year.
As somebody who struggled to follow my Garmin training plan fr this reason, this is an awesome idea. I'm highly partial to at home fitness apps that adapt with you instead of being generic but claiming personalized. Does it adapt from the first run you do with Kaizen or is there a "learning" period to learn a users habits?
the adaptive piece is really interesting - most training apps just expect you to stick to the schedule no matter what. how does it actually adjust? like if you miss a few days or run longer than planned, what kind of changes does it make to keep you on track?
Hey Josh! It's super cool. I'm currently using another app and I can really feel all you're expressing here. My own plans broke when life happened and needed something like kaizen. Wish you all the best here!
As someone who has always preferred to run freely based on how I’m feeling or sometimes constricted by busy days and weeks, I struggled to follow prescribed training plans, as sometimes they would end up feeling like an extension of work. One more to-do in the calendar. This app finally solved that issue, and it quietly become my main training driver. Couldn’t be thankful enough for it.
No more skipping running with friends because I have a specific workout to do.
No more big question marks about what sort of shape I’m in and having to test it or prove it in workouts.
The more I used the app the more I realised I was back to my initial years of running freely and enjoying it.
And when I go to a race I know what my fitness is translating to in race times (it surprisingly always gets the prediction extremely close!).
I even tested not doing anything close to potential “race pace” for months on end and then raced a 10k simply on feel and voila: it matched the pace that Kaizen was predicting for that distance (that I hadn’t run before in training).
Lining up to the start line of
Boston Marathon today with a good grasp of my finishing time thanks to Kaizen! Love the flexibility!
congrats on the launch! the adaptive angle stands out. Most running plans are fixed 16-week blocks that punish you for a bad week 7. How does kaizen decide when to push versus back off? Pace trends, RPE, missed sessions, or a mix?
Been using kaizen for a few months now and generally really enjoying it! Sometimes I find the mileage goals are a bit tooo high (but I'm not generally a high mileage runner), but honestly, the predictions are pretty accurate (I ran a tempo half marathon a few weeks back and it had the pace spot on). I really like that you can plan your week to hit your goal, and the adjustments you get after each run to your goal time. I also like that you have a predicted time for all the distances (they're not just focused on the marathon, like half of the running community seems to be at the minute!) Also a big fan of the "Tailor your prediction" function - I used it just this morning and now I feel my marathon predicted time is (hopefully) a lot closer to reality!
I work with a coach, so kaizen is more of a complement to my training / let's me see if I'm on track for my goal, but I am a fan and would recommend (I just wish I knew a little more about the science behind it and how it calculates its figures!)
Having used Kaizen (and a host of other running apps) it's definitely one I recommend to others.
The training plan gives you the flexibility to run when and how you like. For me, this allowed me to listen to my body a lot better, pushing on days I felt fresher, and taking it easier when I needed the rest. This isn't something I've ever seen in other apps (and I've no doubt is part of the reason so many other apps are driving people into injuries)
(As I understand it) The weekly targets are built on a solid scientific and data led basis, which means I can be confident that the goals I've set are going to be hit. Literally just last weekend I met another Kaizen subscriber who ran a new PB at ParkRun having used Kaizen in training.
Kaizen is a hard app to recommend, its ui is slow and clunky, the plans that it gives you are confusing and the price is pretty steep for something that has these issues.
The app tells you how far you should run in the week and lowers the amount of distance if you've had a particularly hard run (tempo), there are ways to say you are planning to run x time at y event but there is no specific plan like runna or garmin it just tells you to run distances per week.
If your looking for future weeks they dont update unless you plan runs in their excruciating interface - and even then the distance doesn't seem to be affected until the week is complete.
Id say this app is good if you just want a weekly goal and no specific session runs i.e. 3x5 at 5km pace, if you want to do that you have to do it off your own back and setup your session yourself.
As i say difficult app to recommend to anyone really.
P.s. i did try and email them some suggestions and they told me that they were working on some of them, now that they've officially launched on product hub i can see that it was not true.
I wouldn't re-sub to this app.
Many runners bounce between Garmin Coach/DSW and apps like Runna—what’s the specific breaking point that makes someone realize they need kaizen, and what do they get in week 1 that they can’t get from those tools?
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 231 upvotes and 23 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.
kaizen was featured in Health & Fitness (82.5k followers), Running (555 followers) and Pitch Berlin on Product Hunt. Together, these topics include over 25.1k products, making this a competitive space to launch in.
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.
Want to see how kaizen stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
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.