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The Gear Atlas · Instruments

Heart rate straps for running and hybrid intervals

Wrist sensors struggle when you grip a sled rope or a kettlebell. A strap keeps reading.

Reviewed 5 Nov 2026 · 3 sources · 5 picks

In a study of 50 adults, a chest strap agreed almost perfectly with an ECG across treadmill, bike and elliptical sessions, while wrist-worn optical monitors were less consistent 1. Hybrid sessions add tight grips and wrist flexion, which are hard on optical sensors too.

A chest strap reads the heart's electrical signal, like an ECG. An arm band uses light, sits on the upper arm and is more comfortable, but expect less precision in hard intervals 1.

At a glance
Criteria

What to look for

01

Electrodes for accuracy

The study authors recommend an electrode chest monitor whenever accurate heart rate matters 1.

02

Two ways to connect

Look for both Bluetooth and ANT+, so one sensor talks to your watch, phone and gym machines. The Polar H10, for example, supports both 3.

03

A battery you can swap

Coin-cell straps run for a long time: the Polar H10 is rated at 400 hours on a CR 2025 cell 3.

04

Fit you forget about

A strap should sit snug just below the chest muscles. A soft textile strap chafes less on long runs.

5 picks

Worth a look

  1. Chest strap

    Polar H10

    Against an ECG Holter it detected 99.6% of heartbeats correctly, and 99.4% during high-intensity activity; the study was partly funded by Polar 2. Connects over Bluetooth and ANT+ 3.

    Best for Accuracy and intervals

    Check on Amazon *Affiliate link
  2. Chest strap

    Garmin HRM-Pro Plus

    Garmin's chest strap: the natural pairing if you already train with a Garmin watch.

    Best for Garmin watch owners

    Check on Amazon *Affiliate link
  3. Chest strap

    Wahoo TRACKR Heart Rate

    Wahoo's chest strap, popular with indoor-cycling and app users. Check it pairs with your watch before you buy.

    Best for Apps and indoor training

    Check on Amazon *Affiliate link
  4. Optical arm sensor

    Polar Verity Sense

    Worn on the upper arm instead of the chest. Optical sensors are less precise in hard intervals than a strap 1.

    Best for Comfort on easy days

    Check on Amazon *Affiliate link
  5. Optical arm sensor

    COROS Heart Rate Monitor

    COROS's arm band sensor. A comfortable alternative for COROS watch users.

    Best for COROS watch owners

    Check on Amazon *Affiliate link

As an Amazon Associate I earn from qualifying purchases.

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FAQ

Questions

Do I need a chest strap for Hyrox training?

Not to train well. It helps if you train by heart rate zones, because wrist sensors were less consistent than a strap in research 1.

Chest strap or arm band?

A chest strap agreed best with an ECG 1. An arm band is optical: comfortable, and fine for easy runs.

Can I wear a chest strap in a race?

Most racers can; check the current rulebook if you are unsure.

References

Sources

  1. Gillinov S, Etiwy M, Wang R, et al. Variable accuracy of wearable heart rate monitors during aerobic exercise. Med Sci Sports Exerc. 2017;49(8):1697–1703.
  2. Gilgen-Ammann R, Schweizer T, Wyss T. RR interval signal quality of a heart rate monitor and an ECG Holter at rest and during exercise. Eur J Appl Physiol. 2019;119(7):1525–1532.
  3. Polar Electro. Polar H10 user manual: technical specifications and care instructions. support.polar.com. Accessed 2026-11-05.
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Heart rate straps for running and hybrid intervals

Wrist sensors struggle when you grip a sled rope or a kettlebell. A strap keeps reading.

In a study of 50 adults, a chest strap agreed almost perfectly with an ECG across treadmill, bike and elliptical sessions, while wrist-worn optical monitors were less consistent. Hybrid sessions add tight grips and wrist flexion, which are hard on optical sensors too.

A chest strap reads the heart's electrical signal, like an ECG. An arm band uses light, sits on the upper arm and is more comfortable, but expect less precision in hard intervals.

What to look for

Worth a look

  1. Polar H10

    Chest strap. Against an ECG Holter it detected 99.6% of heartbeats correctly, and 99.4% during high-intensity activity; the study was partly funded by Polar. Connects over Bluetooth and ANT+. Best for: Accuracy and intervals.

    Check on Amazon *Affiliate link

  2. Garmin HRM-Pro Plus

    Chest strap. Garmin's chest strap: the natural pairing if you already train with a Garmin watch. Best for: Garmin watch owners.

    Check on Amazon *Affiliate link

  3. Wahoo TRACKR Heart Rate

    Chest strap. Wahoo's chest strap, popular with indoor-cycling and app users. Check it pairs with your watch before you buy. Best for: Apps and indoor training.

    Check on Amazon *Affiliate link

  4. Polar Verity Sense

    Optical arm sensor. Worn on the upper arm instead of the chest. Optical sensors are less precise in hard intervals than a strap. Best for: Comfort on easy days.

    Check on Amazon *Affiliate link

  5. COROS Heart Rate Monitor

    Optical arm sensor. COROS's arm band sensor. A comfortable alternative for COROS watch users. Best for: COROS watch owners.

    Check on Amazon *Affiliate link

Before and after: Wet the electrode pads before you put the strap on and rinse it after each use, as Polar's manual advises. Sweat left on the pads keeps the sensor awake and drains the battery.

Questions

Do I need a chest strap for Hyrox training?

Not to train well. It helps if you train by heart rate zones, because wrist sensors were less consistent than a strap in research.

Chest strap or arm band?

A chest strap agreed best with an ECG. An arm band is optical: comfortable, and fine for easy runs.

Can I wear a chest strap in a race?

Most racers can; check the current rulebook if you are unsure.

Sources

  1. Gillinov S, Etiwy M, Wang R, et al. Variable accuracy of wearable heart rate monitors during aerobic exercise. Med Sci Sports Exerc. 2017;49(8):1697–1703.
  2. Gilgen-Ammann R, Schweizer T, Wyss T. RR interval signal quality of a heart rate monitor and an ECG Holter at rest and during exercise. Eur J Appl Physiol. 2019;119(7):1525–1532.
  3. Polar Electro. Polar H10 user manual: technical specifications and care instructions. support.polar.com. Accessed 2026-11-05.