MARLVEL
Rhythm SYNC. icon

Rhythm SYNC.v2.21

Released December 30, 2025Major

iOS

What changed

  • New featureIntroduced HRV Mode for Rhythm+2.0 to track stress, recovery, and readiness
  • New featureEnabled pairing with external HRV apps while in HRV mode
  • New featureAdded support for toggling modes via triple button press

Original release notes

HRV Mode on the Rhythm+2.0 brings advanced performance insights to your training, letting you track your body’s stress, recovery, and readiness with clinical-level precision. By measuring the subtle variations between each heartbeat, it delivers a deeper understanding of how your body responds to workouts, sleep, and daily stress. It’s a powerful new layer of intelligence that turns the Rhythm+2.0 into more than a heart rate monitor—it’s your personal performance coach. Pair to your favorite HRV app while in HRV mode.

Once firmware has been updated, activate HRV Mode with a triple button press and back to Heart rate mode with a triple button press.

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