Comparison

RUN interval vs Fartlek Interval Trainer

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

Head to head
About

RUN interval

This app simplifies interval and Fartlek running by allowing you to set custom targets for time or distance during hard, easy, and rest efforts. It offers detailed post-run summaries, audio and visual feedback, and an Apple Watch app for enhanced training.

Highlights
  • Customizable interval sessions
  • Time and distance targets
  • Distance Goal option
  • Audio and visual feedback
  • Detailed run summaries
  • Apple Watch app
  • Strava sharing
Features
Read full description

Easily set up and record your Interval and Fartlek running sessions. With the flexibility of using time and/or distance as interval targets for your "Hard", "Easy" and "Rest" efforts. The simple but highly configurable interface on your phone and watch will have you running sooner. Now with a Distance Goal option for your session. Along with great audio and visual feedback, detailed post-run summary, share your runs to Strava, and a full-featured Apple Watch app. You can also record your regular runs with voice-over calling out distance and pace feedback. Key Features: • Easily create flexible custom interval sessions. • Utilize three effort targets "Hard", "Easy" and "Rest" in each set, targeting time or distance (meters or miles). • You can "Skip" any of the three efforts to create flexible sets, like building a progressive intervals session. • NEW: Set a Distance Goal for your session, that repeats the sets from the start until the distance has been reached. • Set a Warm-Up and Warm-Down timer or distance around your session. • Clear and easily glanceable visuals and audio prompts, including vibrations. • Voice-over prompts to save you from looking at the screen, great for iPhone or headphone users. • Voice-over prompts include the upcoming intervals effort and time/distance amount, and your last intervals average pace and heart rate. • Full-featured Apple Watch App! • Heart Rate Zones! (see description below) • Indoor Mode, no GPS, for treadmill running. • Sound Mode, for normal, discrete or silent audio prompts on your watch. • Vibration feedback on both the phone and watch. • Detailed run summary, showing pace for hard and easy efforts. • The run summary also includes interval breakdown, distance breakdown and heart rate details. • Play music or podcasts while running and still hear the audio prompts. • Sharing. Share a summary photo with your friends. • Private data. We don’t send any of your data to a server or share it with anyone. Session Types: • Normal Run – Record a normal run, long or short. • Record Intervals – If you run with a group or do an undefined session, then use the Record Interval option. It allows you to manually change between "Hard" and "Easy" reps, allowing you to record your session. • Custom Intervals – Our fully flexible intervals that allow you to use time and/or distance for the efforts. Add multiple intervals sets together to create the session you want. Sharing: From the summary screen, you can share your runs with friends or across social media. If you want to share directly with friends or across other social media, you can share a summary image with the details of your run. Heart Rate Zones: (Apple Watch Only) Zones are displayed as grouped percentages of your maximum heart rate. Giving you an indication of your current work rate based on your current heart rate. Just enter your maximum workout heart rate into our Settings screen and they will display on your Watch the next time you run. Zone 1: Very Light Effort 50-60% (Gray) Zone 2: Light Effort 60-70% (Blue) Zone 3: Moderate Effort 70-80% (Green) Zone 4: Hard Effort 80-90% (Yellow) Zone 5: Maximum Effort 90-100% (Red) Privacy: We don’t want to know where you have run, that's for you to worry about. We don’t send any of your data to a server or share it with anyone you don't want too. We keep your running records safe in Apple Health so you have control. Apple Heath gives you the control over who accesses your data. We only write and read the data we record from your running. Feedback: And because we don't send any data to a server, we need you to send us feedback and suggestions. Hit the Support link below or visit our website to contact us.

About

Fartlek Interval Trainer

This running app automatically detects spontaneous intervals during Fartlek runs, providing live color-coded feedback on your effort. It also functions as a powerful timer for structured workouts like HIIT and Tabata, offering detailed metrics and syncing with Strava and Apple Health.

Highlights
  • Auto-detection of Fartlek intervals
  • Live color-coded effort feedback
  • Structured workout timer (HIIT, Tabata)
  • Detailed interval metrics
  • Strava and Apple Health integration
  • Advanced effort level detection
Features
Read full description

Build the interval workout you want. Stay on target while you train. Then learn from every session. FiT is an interval timer and training companion for runners on Apple Watch and iPhone. Create classic intervals, HIIT and Tabata workouts—or run freely with automatic Fartlek interval detection. CREATE WORKOUTS YOUR WAY Build simple work-and-rest sessions or advanced workouts with warm-ups, cooldowns, repeated sets and multiple effort levels. FiT makes even complex sessions clear and easy to follow. STAY ON TARGET Color-coded feedback shows whether you’re on pace. Spoken coaching, audio and haptic alerts help you respond without constantly checking your device—and spoken cues automatically match your chosen language. The Dual Progress Ring shows both your current interval and your overall workout progress at a glance. FARTLEK WITHOUT THE BUTTONS Switch to Fartlek mode and run by feel. FiT detects changes in your speed and automatically converts them into recorded intervals. No reaching for your device. No tapping between efforts. Just run. LEARN FROM EVERY WORKOUT See how each interval performed with detailed pace, heart rate, cadence and distance metrics. Compare workouts to understand how your performance changes over time. Personalized coaching insights use your workout data to highlight meaningful patterns and offer practical recommendations for future sessions. ADVANCED EFFORT TRACKING Advanced workouts can distinguish between sprint, hard, moderate and easy efforts, helping you create more varied sessions and analyze every effort afterwards. APPLE WATCH, IPHONE AND YOUR FITNESS APPS Train in your chosen language on Apple Watch or iPhone. Create and edit interval workouts directly on your watch, with controls for inserting, reordering and deleting interval groups. Save completed workouts to Apple Health and sync your sessions with Strava. KEY FEATURES • Flexible interval timer for running, HIIT and Tabata • Automatic Fartlek interval detection • Dual-ring live workout progress • Color-coded pace and effort feedback • Localized spoken coaching, plus audio and haptic alerts • Create and edit interval workouts on Apple Watch • Detailed pace, heart rate, cadence and distance metrics • Performance tracking for every interval • Workout comparisons and personalized insights • Sprint, hard, moderate and easy effort levels • Apple Health and Strava integration • Light and dark appearance Run free. Train smart. Learn from every session. SUBSCRIPTION TERMS FiT offers an optional auto-renewable subscription. Payment will be charged to your Apple ID account at confirmation of purchase. The subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. You can manage or cancel your subscription at any time in your Apple ID account settings. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.iubenda.com/privacy-policy/39192677

Screenshots

RUN interval4 screens
Fartlek Interval Trainer4 screens

Verdict

The call

The clearest difference is update cadence: Fartlek Interval Trainer at every 9 days against RUN interval's every 3 months. RUN interval's advantage is iOS requirement (15.6 vs 26.0). On price, review sentiment, ads and in-app purchases 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. RUN interval sells 2 one-off in-app purchases and Fartlek Interval Trainer sells 4 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

RUN interval ships an update every 3 months, Fartlek Interval Trainer every 9 days. The most recent releases landed on September 25, 2026 and September 22, 2026 respectively.

Scorecard2 real differences · 8 level
RUN interval versus Fartlek Interval Trainer: the parameters behind the verdict, then further details
ParameterRUN intervalFartlek Interval Trainer
PriceFreeFree
Rating4.7 (1K ratings) — better—
Positive reviews77.5% of reviews — better75.0% of reviews
Number of ratings1K — better—
Update frequencyEvery 3 monthsEvery 9 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFreemium
DevicesiPhone, iPod, Apple Watch — betteriPhone, Apple Watch
Requires iOS15.6 — better26.0
Further details — not scored
Size34 MB84 MB
Age rating4+4+
DeveloperCAN YOU HEAR ME SOFTWARERichard English

Customer experience

RUN interval

All ratings1,003 ratings
Positive94.3%
Neutral1.6%
Negative4.1%
Written reviews191 reviews
Positive77.5%
Neutral5.2%
Negative17.3%

Fartlek Interval Trainer

Written reviews4 reviews
Positive75.0%
Neutral0.0%
Negative25.0%

In-app purchases

2 purchases

RUN interval

One-time2
  • The full RUN interval$1.99
  • The full RUN interval$3.99
4 purchases

Fartlek Interval Trainer

Subscriptions2
  • Monthly$0.991 Month
  • Annual7 Days trial$6.991 Year
One-time2
  • RemoveAds$0.99
  • Lifetime$14.99

Questions

Is RUN interval free?
RUN interval is free to download, with in-app purchases available.
Is Fartlek Interval Trainer free?
Fartlek Interval Trainer is free to download, with in-app purchases available.
Do RUN interval or Fartlek Interval Trainer have ads?
Neither RUN interval nor Fartlek Interval Trainer shows ads.
Which is updated more often, RUN interval or Fartlek Interval Trainer?
RUN interval ships an update every 3 months, and Fartlek Interval Trainer every 9 days. Most recently, RUN interval was updated on September 25, 2026 and Fartlek Interval Trainer on September 22, 2026.

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