Interval running apps for iPhone and Apple Watch, compared
The best interval running app depends on the job: timing your reps, running reps by distance, following a race plan, or having workouts built for you. We make Fartlek, so instead of a ranking, here are facts you can check on each app's App Store page and website, checked on 1 October 2026, with US prices.
At a glance
| App | Price (US) | Intervals | Apple Watch | Plans or coaching |
|---|---|---|---|---|
| Apple Workout | Free | Time, distance or open steps; alerts for pace, heart rate, cadence and power | Built in; building on iPhone needs watchOS 26 | None |
| Intervals Pro | Free with 1 timer; $2.99 a month, $19.99 a year or $69.99 once | Time or distance; pace and heart-rate targets | Standalone app | None |
| Seconds Pro | $7.99 once | Time | Standalone app (watchOS 26) | None |
| RUN interval | Free; $3.99 for the full app | Time and/or distance: Hard, Easy and Rest | Watch app | None |
| Runkeeper | Free; plans with the Go subscription | Time or distance, with repeats | Watch app | Plans with Go |
| Runna | $19.99 a month or $119.99 a year | Plan sessions; you can't fully design your own | Watch app, or sends sessions to Apple Workout | Coach-built plans from 5K to ultra |
| Nike Run Club | Free | Audio Guided Runs, including speed intervals | Watch app | Plans in some countries |
| Fartlek | Free with a free run every week; $4.99 a month or $29.99 a year | Time or distance, with an effort target for every step | Watch app, or sends plan runs to Apple Workout | AI coach that builds runs and adapts 5K, 10K and fitness plans |
Apple Workout (free, built in)
If you have an Apple Watch, you already have a capable interval builder: warm-up, work and recovery steps by time, distance or open, a cool-down, and alerts for pace, heart rate zone, cadence or power. Since iOS 26 you can also build these workouts on iPhone, with repeat blocks, as long as the Watch runs watchOS 26. There are no effort targets and no training plans, and without a Watch you can't use custom workouts. How to run intervals on Apple Watch.
Intervals Pro
A flexible interval timer that also handles distance: intervals by time or distance, pace and heart-rate targets for each interval, spoken interval names in 11 languages and a standalone Apple Watch app. There are no training plans. Free with 1 timer; Premium costs $2.99 a month, $19.99 a year or $69.99 once.
Seconds Pro
A polished interval timer you pay for once, $7.99, with nothing else to unlock: rounds, varied intervals and chained timers, spoken interval names, music that ducks under the cues, and a standalone Watch app that needs watchOS 26. Its App Store page describes timed intervals only, so it isn't the pick for reps by distance. The free Seconds app is a separate product that locks each timer after one use until you buy the $7.99 upgrade.
RUN interval
Built for runners: Hard, Easy and Rest efforts by time and/or distance, sets, warm-up and cool-down, and voice prompts that tell you the next effort along with your last interval's pace and heart rate. Your data stays in Apple Health. Free to try, $3.99 for the full app, and in English only.
Runkeeper
A run tracker from ASICS that also lets you build custom intervals by time or distance, with repeats, warm-up and cool-down, and syncs them to its Watch app. Custom intervals are stored on the phone only. Training plans and the full guided workouts come with the Runkeeper Go subscription.
Runna
Runna is built around training plans from elite coaches, personalized for races from 5K to ultra, with every session laid out for you. You can't fully design your own workouts. It has its own Watch app with audio cues, or it can sync sessions into Apple's Workout app, where Runna's audio cues don't play. It costs $19.99 a month or $119.99 a year, with a 7-day free trial.
Nike Run Club
Free, with no in-app purchases: audio Guided Runs, including speed intervals, and coach-built training plans in some countries. There is no tool to build your own interval workout.
Fartlek
Our app, so judge for yourself. Intervals by time or distance, every step with an effort target by feel, from 30% to 100%; voice, color and haptic cues that work with the screen locked; a library of 25 workouts with classics like Yasso 800s and the Norwegian 4x4; and an AI coach, Pete, who builds runs from a few words or a photo and writes a 5K, 10K or fitness plan that adapts every week. Plan runs can go to Apple's Workout app. It doesn't use pace or heart-rate targets, and the AI features need a connection. Free with a run every week; Premium costs $4.99 a month or $29.99 a year, with a 3-day free trial on the yearly plan.
How to choose
- You have an Apple Watch and just need reps: start with Apple's Workout app. It's free.
- You want a timer you set up once: Seconds Pro for time, Intervals Pro for time or distance.
- You run reps by distance and want your pace read out: RUN interval.
- You want a race plan laid out for you: Runna.
- You want free audio-guided runs: Nike Run Club.
- You want workouts built for you and run by feel: Fartlek.
Prices are from the US App Store and vary by country. Features are as each app's App Store page and website described them on 1 October 2026. Apps change, so check before you subscribe.