Comparison

kaizen | Adaptive Run Training vs Shape Calendar

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

kaizen | Adaptive Run Training

This app analyzes your running history from connected services to create personalized training plans. It adapts to your progress and goals, offering flexible workout structures to help you improve your performance for races or general fitness.

Highlights
  • Load-based run training analysis
  • Connects with Strava, Garmin, Apple Health
  • Personalized training load calculation
  • Supports 5K, 10K, half marathon, marathon goals
  • Flexible training structures (Even Spread, 1 Long 1 Hard, Build Your Own)
  • Adaptive workout adjustments
  • Distance, pace, and elevation load calculation
Features
Read full description

kaizen is load-based run training for committed runners, starting with the running you have already done. Connect Strava, Garmin or Apple Health so kaizen can analyse your training and race history. See how your fitness is developing, what shape you are in now and what your training suggests is possible. kaizen then connects that picture with your goal and timeline to map the weekly training load needed ahead. kaizen does not process or store location data. Train toward a 5K, 10K, half marathon or marathon—or set a rate of improvement without an upcoming race. CHOOSE HOW YOU TRAIN Use a suggested training structure or build the week yourself: • Even Spread for a calm, repeatable weekly rhythm • 1 Long, 1 Hard to anchor the week around one longer run and one harder effort • Build Your Own for complete control over the week Choose structured workouts, plan your runs and see how each session contributes to your weekly target. ADAPT AS YOU GO Move or edit sessions when the week changes. Every completed run recalculates both your current fitness and the training load needed ahead. HOW LOAD WORKS Equal distances do not always represent equal training. kaizen uses distance, pace and elevation—along with supported cross-training minutes—to understand the load created by different activities. This keeps the bigger picture consistent while giving you control over how the work gets done. Start with a seven-day free trial. Terms: https://runkaizen.com/terms Privacy: https://runkaizen.com/privacy

About

Shape Calendar

Features
Read full description

Shape is a training planner for runners, cyclists and triathletes. It pulls in your workouts and recovery data, shows how your training is going, and lets you plan ahead in the calendar or with Claude and ChatGPT. TODAY See your readiness each morning, from your sleep, resting heart rate and HRV. Training load balance, fitness, fatigue and form, all including what you've planned, so a heavy week shows up before you're overtraining. CLAUDE AND CHATGPT Shape works as an MCP connector. Ask how your last block went, why a run felt hard, or to plan the next four weeks. Claude and ChatGPT read your workouts, sleep and HRV, and write the plan straight into your calendar, and it syncs to your devices. CALENDAR Every sport in one calendar, planned and done, with your weekly load on top. Plan on your phone or the web, and sync your plan to Google or Apple Calendar. BUILD WORKOUTS BY TYPING Type "5x1km at threshold, 2 min easy" and Shape turns it into structured steps, ready for your watch. WATCHES AND APPS Garmin, Apple Watch and Apple Health, Wahoo, Polar and Intervals.icu. Completed workouts, sleep and HRV sync in automatically. Planned workouts go to your Apple Watch, Garmin or Wahoo. WORKOUTS Each run and ride shows the route on a map, charts for pace, heart rate, power and cadence, your laps and time in zones, whichever watch or app recorded it. WHY I BUILT IT I'm Samuel. I ran the Stockholm half marathon with a cold, ended up with pneumonia, and spent months working back from 15-minute walks. I built Shape to plan that comeback and now use it every day to help me train smarter. Terms of Use: https://shapecalendar.com/terms Privacy Policy: https://shapecalendar.com/privacy

Screenshots

kaizen | Adaptive Run Training4 screens
Shape Calendar4 screens

Verdict

The call

The clearest difference is update cadence: Shape Calendar at weekly against kaizen | Adaptive Run Training's fortnightly. kaizen | Adaptive Run Training's advantage is iOS requirement (16.4 vs 26.0). On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. kaizen | Adaptive Run Training sells 10 in-app purchases, starting at $12.99 per month and Shape Calendar sells 2 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

kaizen | Adaptive Run Training ships an update fortnightly, Shape Calendar weekly. The most recent releases landed on November 13, 2026 and November 12, 2026 respectively.

Scorecard2 real differences · 8 level
kaizen | Adaptive Run Training versus Shape Calendar: the parameters behind the verdict, then further details
Parameterkaizen | Adaptive Run TrainingShape Calendar
PriceFreeFree
Rating4.7 (31 ratings) — better—
Positive reviews58.0% of reviews—
Number of ratings31 — better—
Update frequencyFortnightlyWeekly — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhoneiPhone
Requires iOS16.4 — better26.0
Further details — not scored
Size97 MB19 MB
Age rating4+4+
DeveloperRun Kaizen LTDSamuel Christoffer Kraft

Bugs and requests

kaizen | Adaptive Run Training

Reported bugs

25 issues
  • Setup process crashes or loops
  • App crashes frequently
  • Mileage calculations are incorrect
  • Planned mileage doesn't add up correctly
  • App doesn't get past the first step
Show 20 more
  • Race prediction screen freezes
  • App doesn't work at all
  • Data imports incorrectly (mileage/pace)
  • Issues with unit conversion (miles/kilometers)
  • Subscription charge without reminder
  • Weekly targets change based on paces
  • Only shows one week ahead
  • Can't get past prediction screen
  • Stuck on loading stage
  • Imported Strava data is wonky
  • Race predictor only gives marathon distance prediction
  • Training days logged as previous day
  • Cannot control subscription
  • Inconsistent distance recommendations
  • Records disappear and reappear
  • Improve prediction section hides event selection
  • Week planning tool shows wrong paces
  • Marathon goal always defaults to 2:00:00
  • Can't consistently log in
  • App is immature and has bugs

Requested features

9 requests
  • Allow editing of runs
  • More personalization in training plans
  • Ability to start the training week on different days
  • Consider elevation in training calculations
  • Add more workout suggestions and paces
Show 4 more
  • Predict times for distances other than marathon
  • FAQ and tutorials for better understanding
  • Ability to plan runs in decimals
  • Integration with other platforms beyond Strava

Shape Calendar

Not enough reviews yet to summarise bugs or requests.

In-app purchases

10 purchases

kaizen | Adaptive Run Training

Subscriptions10
  • Subscription$12.991 Month
  • Monthly Subscription7 Days trial$14.991 Month
  • Monthly Subscription14 Days trial$14.991 Month
Show 7 more
  • Subscription$19.993 Months
  • Subscription$24.993 Months
  • Quarterly Subscription14 Days trial$34.993 Months
  • Quarterly Subscription7 Days trial$34.993 Months
  • Subscription$49.991 Year
  • Annual Subscription7 Days trial$89.991 Year
  • Annual Subscription14 Days trial$89.991 Year
2 purchases

Shape Calendar

Subscriptions1
  • Shape Pro Monthly14 Days trial$4.991 Month
One-time1
  • Lifetime$99.99

Questions

Is kaizen | Adaptive Run Training free?
kaizen | Adaptive Run Training is free to download, with in-app purchases available.
Is Shape Calendar free?
Shape Calendar is free to download, with in-app purchases available.
Do kaizen | Adaptive Run Training or Shape Calendar have ads?
Neither kaizen | Adaptive Run Training nor Shape Calendar shows ads.
Which is updated more often, kaizen | Adaptive Run Training or Shape Calendar?
kaizen | Adaptive Run Training ships an update fortnightly, and Shape Calendar weekly. Most recently, kaizen | Adaptive Run Training was updated on November 13, 2026 and Shape Calendar on November 12, 2026.

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