Saturday vs Subintervals
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Saturday
This app provides personalized fueling and hydration plans for endurance athletes. It uses science-based recommendations tailored to your training and environment, eliminating guesswork and expensive coaching. Achieve your best performance with confidence.
- Personalized fuel and hydration plans
- Science-based recommendations
- Tailored to training and environment
- Eliminates guesswork
- Reduces reliance on coaching
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Saturday is personal fueling for runners, cyclists and triathletes, built by a board-certified sports dietitian and a PhD sport scientist, both former Team USA athletes. Tell it about your training session or race, and it plans what to drink and eat each hour from how much you sweat and the weather, then turns that plan into drinks you mix yourself or the gels and drink mixes you use. "Saturday has been incredible both with taking the guess work out of fueling and improving my workouts... definitely recommend!" - Dan Laurich, Triathlete "My half marathon was AMAZING! 7-minute PR! The fuel was great. Everything just clicked. Big confidence boost. I feel ready to get back to my training tomorrow. I’m happy!" - Kasie P., Runner "If you want to get out of the black box of mid ride/race nutrition needs, Saturday is the app for you!" - Skip Kastroll - XC & Enduro MTB racer "I’ve trusted Saturday for everything. From hot laps with the guys to ultra endurance gravel races." - Tarah Romano, Cyclist "I hate training without it." - Michelle Howe, professional triathlete Saturday makes elite endurance nutrition accessible and easy so you can be confident and relaxed in training and on race day. Saturday is designed to deliver the best training session of your life. Gone are the days of shelling out hundreds on hydration products that are just wild guesses or some corporate-influenced industry "standard." You deserve better. Better science. Better individualization. Optimized fuel & hydration tailored to you, your training, and your environment, Saturday will revolutionize your endurance experience. No more paying premium prices for private nutrition coaching, just to have confidence in your fuel & hydration plan. We should all be able to fuel the sports we love. Our science. Your joy. Taking you farther. End User License Agreement (EULA): https://saturday.fit/app-terms Privacy policy: https://saturday.fit/app-privacy
Subintervals
Visualize your training data with detailed displays and interactive graphs. Customize your analysis and sync seamlessly with intervals.icu for up-to-the-minute insights into activities, events, and performance metrics.
- Detailed activity and event visualization
- Interactive performance graphs
- Seamless intervals.icu sync
- Customizable data analysis
- Actionable training insights
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Elevate Your Training with Subintervals Subintervals transforms your intervals.icu data into actionable insights. This app brings your training activities, events, and performance metrics to life through detailed displays and interactive graphs. Customise and control your data for a tailored analysis, and seamlessly sync with intervals.icu for up-to-the-minute information. Key Features: - Detailed visualisation of activities and events. - Dynamic, interactive graphs for performance tracking. - Effortless sync with intervals.icu. Please note that it is an independent application developed by an enthusiast keen on providing a complementary tool to the official platform.
Screenshots
Verdict
The clearest difference is ratings volume: Saturday at 155 against Subintervals's 2. On price, rating, review sentiment and update cadence 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
Both are free to download. Saturday sells 2 in-app purchases, starting at $5.99 per month and Subintervals sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 5.0 for Saturday against 5.0 for Subintervals. That said, the two scores are not equally well evidenced: Saturday has 155 ratings behind it against 2, so its average is the more settled of the two. Written reviews are what separate them: 97% of Saturday's written reviews are positive against 100% of Subintervals's.
Saturday ships an update every 11 days, Subintervals weekly. The most recent releases landed on October 27, 2026 and October 24, 2026 respectively.
| Parameter | Saturday | Subintervals |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (155 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 97.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 155 — better | 2 |
| Update frequency | Every 11 days | Weekly — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone | iPhone, iPad — better |
| Requires iOS | 17.0 | 16.4 — better |
| Further details — not scored | ||
| Size | 152 MB | 109 MB |
| Age rating | +12 | 4+ |
| Developer | Saturday Morning LLC | Inaki Arroyo Nebreda |
Customer experience
Saturday
Subintervals
Bugs and requests
Saturday
Reported bugs
2 issues- Login experience issues
- Swim hydration recommendations causing excessive bathroom breaks for some users
Requested features
5 requests- Per-bottle recipe breakdown instead of bulk mixing calculations
- Recovery advice and prescriptions
- Native mobile application instead of web app
- More granular ingredient customization options
- Improved swim-specific hydration recommendations
Subintervals
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Saturday
- 1-month subscription$5.991 Month
- 1-year subscription1 Month trial$49.991 Year
Subintervals
- Coffee$3.99
- Lunch$11.99
- Big Thanks$17.99
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- Sponsor$44.99








