Best Heart Rate Monitors for Interval Training in 2026
Compare three chest-strap heart rate monitors for interval training, with clear guidance on live data, running metrics, swim use and device compatibility.
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Prices and availability are accurate as of the time of publication and are subject to change.
Best heart rate monitors for interval training in 2026
The Polar H10 is our best heart rate monitor for interval training because it combines ANT+ with Bluetooth, can connect to two Bluetooth devices at once, and keeps a useful onboard recording option. It is the sensible choice when a hard session changes quickly from treadmill to bike or watch to phone. We compared the three straps below by their documented connection options, workout data and the compromises that matter when short recoveries make a missed reading especially frustrating.
How to choose a heart rate monitor for interval training
Interval sessions expose a monitor to rapid changes: a warm-up, repeated hard efforts, recovery jogs and often sweat-soaked clothing. A chest strap measures electrical activity close to the heart, but it still needs good skin contact. Wet the electrode areas before starting, tighten the strap enough that it cannot slide, and check the selected sensor inside the workout app before the first fast rep. Those small habits are more useful than chasing a long feature list.
Connection type is the next practical filter. ANT+ is helpful when a watch, bike computer or gym console needs the same signal. Bluetooth Low Energy suits phones and many indoor-training apps. The H10 can maintain two Bluetooth connections, whereas the H9 uses one Bluetooth connection alongside ANT+. Garmin's HRM-Pro Plus also broadcasts over ANT+ and Bluetooth Low Energy, but its advanced running information is most useful with a compatible Garmin watch.
Think about where the workout happens. A runner who wants cadence-related form data and treadmill pace has a different requirement from a lifter tracking work-to-rest timing on a phone. Swimming introduces another distinction: a strap may record during an activity even when live transmission is limited by water, then sync the data later. Finally, straps are wearable parts. Confirm the size range, rinse after salty sessions, and do not treat a removable battery or a washable strap as trivial details when the monitor will be used several times a week.
| Product | Best for | Price |
|---|---|---|
| Polar H10 | Best overall | View |
| Garmin HRM-Pro Plus | Best for runners | View |
| Polar H9 | Best value | View |
Polar H10: the flexible pick for mixed training
Polar H10 chest strap
The Polar H10 earns the overall badge because its connection choices are unusually flexible for an interval athlete. It broadcasts through ANT+ and Bluetooth, and Polar specifies two simultaneous Bluetooth connections, so a compatible watch and a phone app can both receive a workout without a manual handoff. It also has internal memory for one training session and is waterproof for swim use. The soft strap has silicone dots and a buckled adjustment, practical details when sprints and burpees would otherwise move a sensor. Choose it if your training changes between running, cycling, classes and different apps. Its limitation is that its strength is measurement and compatibility, not Garmin-specific running-dynamics coaching; buyers who want those metrics on a Garmin watch should look at the HRM-Pro Plus instead.
Pros
- Two Bluetooth connections can feed a phone app and compatible watch during the same session
- Onboard memory can preserve one workout when a receiving device is out of reach
- Silicone dots and an adjustable soft strap help keep the electrode belt in place during fast changes of direction
Cons
- Does not add Garmin running dynamics for athletes building sessions around Garmin coaching fields
- The M-XXL strap range must be checked carefully if a smaller fit is needed
Garmin HRM-Pro Plus: for interval runners using Garmin
Garmin HRM-Pro Plus
Garmin's HRM-Pro Plus is the specialist option for runners whose interval plan already lives in Garmin Connect and on a compatible Garmin watch. Alongside ANT+ and Bluetooth Low Energy heart-rate transmission, Garmin documents running dynamics including vertical oscillation, ground contact time, stride length and vertical ratio. It can also calculate pace and distance for treadmill or indoor-track workouts, useful when a repeated session is not outdoors. The strap stores heart-rate data during swimming or when the watch is out of range, then forwards it afterward, and its quarter-turn battery door avoids a tool for battery changes. Pick it for running-focused feedback rather than just a pulse number. The tradeoff is clear: many of its headline metrics depend on a compatible Garmin ecosystem, and the module is integrated with the strap rather than designed as a simple swap-on sensor.
Pros
- Reports documented running dynamics such as ground contact time and vertical oscillation to compatible Garmin devices
- Calculates pace and distance for treadmill or indoor-track interval sessions
- Quarter-turn battery door supports a tool-free battery change
Cons
- Its most distinctive running fields require a compatible Garmin watch and Garmin workflow
- Integrated module and strap are less convenient when only the textile portion needs replacing
Polar H9: a focused strap for the essentials
Polar H9 chest strap
The Polar H9 is the focused alternative for an athlete who wants dependable live heart-rate data without paying for onboard recording or advanced running analysis. Polar lists both ANT+ and Bluetooth connectivity, which covers a broad mix of watches, cardio equipment and phone apps, while its single Bluetooth connection keeps the setup uncomplicated. Its soft chest strap is waterproof and the battery is user-replaceable, so it remains a straightforward choice for indoor cycling, circuit training and basic interval alerts. Select the H9 when your only destination is one display and you would rather spend attention on target zones than extra metrics. Its limitation is important before checkout: it cannot keep two Bluetooth links active and does not include the H10's one-session memory, so it is less adaptable for athletes who record in more than one place.
Pros
- ANT+ and Bluetooth support covers many watches, gym machines and phone training apps
- Single Bluetooth pairing makes a phone-only or one-watch setup easy to manage
- User-replaceable battery avoids treating the whole monitor as disposable after normal battery life
Cons
- Only one Bluetooth connection is available at a time
- No onboard workout memory for sessions performed away from the receiving device
Which strap fits your workout setup?
Start with the display you trust during the hard part of the interval. If that is a Garmin watch and you review stride-related numbers after every running block, the HRM-Pro Plus has the strongest reason to exist. It does more than send a heart-rate signal: it adds the running and indoor-pace information that makes a Garmin session easier to interpret. That extra data is not an advantage if it remains outside the platform you use.
For a mixed routine, the H10 is less restrictive. Two Bluetooth connections make it easier to keep a backup recording path, and the one-session memory is reassuring for a swim or a workout where a phone cannot stay close. Neither feature removes the need to confirm compatibility with a particular app, but both reduce friction across devices. The H9 is the clean option when one watch, bike computer or phone is enough. It keeps the core protocol support without asking the buyer to pay for features they will never open.
Do not use a new strap for the first time on an important workout. Pair it at home, test an easy warm-up, and learn whether your chosen app uses Bluetooth or ANT+ for the preferred sensor. For high-intensity work, fit and skin contact are equally important: a loose strap can create a problem that no specification can solve.
FAQ
Are chest straps better than wrist sensors for intervals?
Chest straps are often a practical choice for interval training because they read the heart's electrical signal and sit securely on the torso. Wrist sensors can be convenient, but rapid arm motion, gripping equipment and sweat can make fit more consequential. The better choice is the one that gives stable readings in your own workout and connects to the device where you make training decisions.
Can I connect one heart rate strap to a phone and watch?
It depends on the model and protocols. The Polar H10 is documented to support two simultaneous Bluetooth connections, which can suit a compatible phone and watch. ANT+ can also broadcast to multiple compatible receivers. The Polar H9 has one Bluetooth connection, so check the watch, app and sensor settings before expecting parallel Bluetooth recording.
What should I do if a chest strap reads erratically at the start?
Moisten the electrode areas, position the strap firmly below the chest muscles and make sure the selected sensor is the strap rather than a watch's optical reading. A dry strap at the beginning of a session can be less stable. Rinse it after workouts and follow the maker's care guidance, since residue and a worn strap can also affect contact.
Prices and availability are accurate as of publication and can change.