# Darwin: Adaptive Training — Triathlon & Marathon Plans

> Adaptive triathlon and marathon training plans that rebuild weekly based on your performance. (iPhone/iPad app by Justin Ramirez.)

- Source: https://appshunter.io/ios/app/darwin-adaptive-training/id6790443867 (this page in markdown: same URL + `.md`)
- Developer: [Justin Ramirez](https://appshunter.io/developer/6790443869)
- Category: Health & Fitness, Sports
- Price: Free with in-app purchases
- Rating: 5.00/5 from 2 App Store ratings · 1 written reviews indexed
- Age rating: 4+
- Requires: iOS 16.4 · 51 MB
- Languages: American English
- Released: 2026-08-26
- Data updated: 2026-09-05
- Monetization: freemium
- User reviews in markdown: https://appshunter.io/ios/app/darwin-adaptive-training/id6790443867/reviews.md

## What is Darwin?

Every training plan you have downloaded assumed a perfect week. Darwin does not.

You have three sports, a job, and a race on the calendar. Then you get sick, or a meeting eats Wednesday, or you sleep five hours three nights running. A PDF plan cannot see any of that. It just keeps counting down, and you fall behind a schedule that was never built for the week you actually had.

Darwin rebuilds your plan every week around what actually happened.

HOW IT WORKS

Tell Darwin your race, your date, and the days you can train. It builds a full week-by-week plan to race day. At the end of each week it asks what you completed, how you slept, how you felt, and whether you fueled your long sessions.

Then it rebuilds the weeks ahead. Nail the week and it progresses you. Miss sessions or sleep badly and it pulls volume back and drops intensity, rather than pretending the week went fine. Every change comes with a plain-language explanation of what moved and why.

A DETERMINISTIC ENGINE, NOT A CHATBOT

This is worth being precise about. Darwin never asks a language model how hard you should train. Every load decision comes from a deterministic engine with hard limits written into it:

Volume never ramps more than 10 percent week over week
Every fourth week is a recovery week at 65 percent load
A bad week can cut your load, but never below 60 percent of what was planned
A real taper into race day, sized to your event

Language models do exactly one job here: turn the engine's decisions into a paragraph you can read. They never make them.

BUILT FOR YOUR RACE

Ironman, 70.3, Olympic, sprint, marathon, half marathon. Darwin also shapes sessions around the course you are actually racing: climbing work for a hilly bike leg, heat-adapted sessions for a hot race, open-water skills if you are not racing in a pool.

FUELING ON THE SESSIONS THAT NEED IT

Every long session carries a carbohydrate target in grams per hour. Every day is tagged low, medium or high carb based on the training load you are actually doing that day. No second app for nutrition.

READINESS FROM REAL DATA

With your permission, Darwin reads sleep, resting heart rate, heart rate variability and completed workouts from Apple Health, and factors them into the weekly rebuild. Your health data stays on your phone.

WHY I BUILT IT

I am a dad and a lawyer, and Eagleman 70.3 was my first one. I went in less fit than I wanted to be and, worse, with my nutrition guessed rather than planned. My stomach turned on me early and the half marathon became a walk between portable toilets. I promised myself never again. Every app I tried wanted me to build my life around a training schedule, and none of them took fueling seriously. So I built the one that does both. Six weeks after I started, I raced a second 70.3 in Maine and took nearly 40 minutes off my time.

WHAT YOU GET

A full plan to race day, rebuilt every week
Carb targets on every long session
Readiness from your sleep, HRV and resting heart rate
Plain-language answers on why the plan changed
Notes on any day, which the next rebuild takes into account
Over 60 races to browse and search
Your plan synced to your account, so a lost phone does not cost you your training

Darwin is free for 7 days. After that it is a subscription, and you can cancel any time in your Apple ID settings.

SUBSCRIPTION DETAILS

Darwin Pro is 9.99 USD per month or 79.99 USD per year, after a 7-day free trial. Payment is charged to your Apple ID at confirmation of purchase. The subscription renews automatically unless cancelled at least 24 hours before the end of the current period. Manage or cancel in your Apple ID account settings. Any unused portion of a free trial is forfeited when you purchase a subscription.

Terms: https://darwinendurance.com/terms
Privacy: https://darwinendurance.com/privacy

## Key features

- Weekly plan rebuilding
- Adaptive volume and intensity
- Race-specific session shaping
- Carbohydrate fueling targets
- Readiness tracking from health data
- Plain-language explanations

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Darwin | $9.99 | per month |
| Darwin | $79.99 | per year |


## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/darwin-adaptive-training/id6790443867/reviews.md

### 5/5 — Exactly what I needed!

*2026-08-28*

I absolutely love this app! I’ve tried other training apps and this is by far my favorite. It keeps me accountable and on track, but what really sets it apart is how it adapts when life happens (pun intended 😂).

As a busy mom, sometimes I don’t get the best sleep, I miss a workout, or my week just doesn’t go as planned. I love that Darwin adjusts my training based on what I actually did and keeps moving me forward instead of making me feel like I’m behind (g***** cough cough). It’s so nice to see those changes happen in real time and know my plan is still personalized to me.

I’m currently training for a half marathon and this has made following a training plan so much easier. I actually look forward to checking the app and seeing what’s next based on my day/week. Highly recommend!

## Frequently asked questions about Darwin

### Does Darwin have ads?

Darwin is ad-free, allowing for an uninterrupted training experience. The app focuses on providing a clean interface for managing your training plans and health data.

### What races can Darwin plan for?

Darwin supports a variety of endurance races including Ironman, 70.3, Olympic, sprint, marathon, and half marathon events. It also tailors sessions based on specific course profiles, such as hilly bike legs or hot race conditions.

### How does Darwin use my health data?

With your permission, Darwin integrates with Apple Health to read sleep, resting heart rate, and heart rate variability. This data is used to factor into your weekly plan rebuilds, providing a more accurate readiness assessment.

### What are the subscription options for Darwin?

Darwin offers two subscription plans: $9.99 per month and $79.99 per year. Both plans include a 7-day free trial, allowing you to experience the adaptive training features before committing.

### How often is Darwin updated?

The latest version of Darwin is 1.0.2, which was last updated on September 1, 2026. Updates typically focus on refining the deterministic engine and improving user experience based on feedback.

### Can Darwin help with nutrition?

Yes, Darwin provides carbohydrate targets per hour for every long session and tags each day with a low, medium, or high carb recommendation based on your training load. This integrates fueling directly into your training plan.

### What is the age rating for Darwin?

Darwin has an age rating of 4+, making it suitable for a wide range of users. The app's focus is on adult endurance training and does not contain age-inappropriate content.

### How does Darwin's training engine work?

Darwin uses a deterministic engine, not a chatbot, to make training load decisions. It adheres to strict limits, such as a 10% week-over-week volume ramp, a recovery week every fourth week at 65% load, and a minimum load of 60% after a bad week.

## Version history (last 3 releases)

### 1.0.2 — 2026-09-01

Your plan now updates itself.

Automatic weekly refresh: when your week wraps, Darwin reads your workouts and sleep from Apple Health, rebuilds next week, and shows you exactly what changed and why. No check-in required (though you can still add how the week felt).
Mid-week adjustments: did Wednesday's long run on Monday? Your week rearranges itself around what you actually did, tells you what moved, and one tap undoes it.
Smarter build for fit athletes: if you start in shape, your plan now holds a sustainable base and saves the biggest weeks for the final stretch before your race, instead of training at peak volume for months. Long rides and runs are capped at what your race actually demands.
Adherence is now a grade: an A means you're on track; a B is a solid week for an athlete with a real life. The exact percentage is still one tap away.
UI/UX updates.

### 1.0.1 — 2026-08-27

HYROX support: full event type with station workouts. Mid-week reshuffle: the plan now follows what you actually did within the week. Fixed a duplicate workout notification.

### 1.0.0 — 2026-08-26

No release notes.

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-05.*