Garmin HRMs for Swimming: HRM-Swim, HRM-Pro Plus, and Choosing the Best One

Which Garmin HRM is best for swimming?

For dedicated swimming, the Garmin HRM-Swim offers superior in-water stability and data capture, while the Garmin HRM-Pro Plus provides a versatile multi-sport solution with internal memory for swimming and broader connectivity for other activities.

Understanding Heart Rate Monitoring in Water

Accurate heart rate (HR) monitoring is a cornerstone of effective training, allowing athletes to gauge effort, manage intensity, and track physiological adaptations. While wrist-based optical heart rate sensors have become ubiquitous in modern smartwatches, their accuracy can be significantly compromised in water. The constant movement, water interference, and light refraction make it challenging for optical sensors to capture a reliable signal.

This is precisely why a dedicated chest strap heart rate monitor (HRM) becomes indispensable for swimmers. Chest straps measure electrical signals from the heart, providing a much more accurate and consistent reading, even in dynamic aquatic environments. However, water also poses a challenge for wireless data transmission; standard ANT+ or Bluetooth signals do not propagate well through water. Therefore, specialized swimming HRMs incorporate internal memory to store heart rate data during your swim, syncing it with your Garmin watch once you exit the water.

Key Features for a Swimming Heart Rate Monitor

When selecting an HRM for swimming, several critical features differentiate a suitable device from a standard one:

• Internal Memory: This is paramount. The HRM must be able to store your heart rate data throughout your swim and then transmit it to your Garmin watch after the activity is complete (when out of the water).
• Water Resistance: An obvious requirement, ensuring the device can withstand prolonged submersion and chlorinated or saltwater environments.
• Non-Slip Design: Traditional chest straps can slip down or shift during powerful push-offs and turns. A swimming-specific HRM often features a wider strap or a high-friction material to stay securely in place.
• Connectivity: While data is stored internally during the swim, the HRM needs to connect to your Garmin watch afterwards. ANT+ is standard for Garmin devices, with Bluetooth Low Energy (BLE) offering broader compatibility for other apps and devices.
• Comfort and Durability: The strap should be comfortable enough for long training sessions and robust enough to withstand the rigors of regular swimming.

Garmin's Dedicated Swimming HRMs

Garmin offers two primary chest strap HRMs that excel in aquatic environments, along with a versatile multi-sport option:

Garmin HRM-Swim

• Purpose: Specifically designed for pool swimming.
• Design: Features a non-slip strap with a sticky, high-friction surface to stay put during flip turns and push-offs. It's also wider than typical straps.
• Data Capture: Stores up to 20 hours of heart rate data during your swim, then automatically sends it to your compatible Garmin watch when out of the water.
• Connectivity: Primarily uses ANT+ for post-swim data transfer.
• Battery Life: User-replaceable CR2032 battery, typically lasting around 18 months (based on 3 hours/week of swimming).

Garmin HRM-Pro / HRM-Pro Plus

• Purpose: A versatile multi-sport HRM, ideal for triathletes and those who cross-train extensively.
• Design: A more traditional, comfortable strap design, though it's still very secure. The "Plus" version features a tool-free battery door for easier replacement.
• Data Capture: Stores heart rate data for swimming, but also captures running dynamics (vertical oscillation, ground contact time, stride length) and transmits real-time heart rate for running, cycling, and other activities.
• Connectivity: Supports both ANT+ and Bluetooth Low Energy, allowing it to connect to a wider range of devices, apps, and gym equipment simultaneously.
• Battery Life: User-replaceable CR2032 battery, typically lasting around 12 months (based on 1 hour/day of use).

Detailed Comparison: HRM-Swim vs. HRM-Pro Plus

Making Your Choice: Factors to Consider

The "best" Garmin HRM depends entirely on your specific training regimen and needs:

• Dedicated Swimmer (Pool Focus): If your primary activity is pool swimming and you rarely engage in other heart-rate-monitored activities, the Garmin HRM-Swim is the superior choice. Its non-slip design is optimized for the unique demands of swimming, ensuring maximum stability during powerful movements, and its sole focus keeps the cost down.

• Open Water Swimmer: While the HRM-Swim is designed for pools, its internal memory works equally well for open water. However, if you're also a runner or cyclist, the HRM-Pro Plus becomes more appealing due to its versatility.

• Triathlete / Multi-Sport Athlete: For those who engage in running, cycling, swimming, and gym workouts, the Garmin HRM-Pro Plus is the undisputed champion. It offers the necessary internal memory for swimming, real-time HR for other activities, and invaluable running dynamics data, making it a comprehensive training tool across all disciplines.

• Budget: The HRM-Swim is typically more affordable, making it an excellent value for swimmers who don't need the multi-sport features.

• Future-Proofing: If you anticipate expanding your training to include more land-based activities or want the flexibility of Bluetooth connectivity, the HRM-Pro Plus offers more long-term versatility.

Optimizing Your Swim Training with an HRM

Once you've selected your Garmin HRM, leveraging its data can significantly enhance your swim training:

• Heart Rate Zones: Understand your personal heart rate zones (e.g., easy, moderate, threshold, maximal). These zones dictate the physiological adaptations you're targeting during different parts of your workout.
• Pacing and Effort: Use your heart rate data to ensure you're maintaining the correct effort level for each interval or set. Avoid starting too fast and fading, or staying too slow during high-intensity efforts.
• Recovery Monitoring: Track your heart rate during recovery periods between intervals. A quicker drop in heart rate can indicate improved fitness.
• Overload and Adaptation: Monitor trends in your heart rate for similar efforts over time. A lower heart rate for the same pace or perceived effort can signal improved cardiovascular fitness.
• Load Management: Combined with your Garmin watch's training status metrics, your HRM data contributes to a holistic view of your training load, helping to prevent overtraining.

Using Your Garmin HRM for Swimming

1. Wear it Correctly: Moisten the electrodes on the back of the strap. Position the strap directly below your sternum, ensuring a snug but comfortable fit.
2. Start Your Activity: Begin a "Pool Swim" or "Open Water Swim" activity on your compatible Garmin watch. The watch will automatically look for the HRM.
3. Swim: The HRM will automatically store your heart rate data during the swim. You won't see real-time HR on your watch screen in the water, as the signal doesn't transmit effectively.
4. Sync Post-Swim: Once you finish your activity and exit the water, the HRM will automatically transmit the stored heart rate data to your Garmin watch. This data will then be integrated into your activity summary and uploaded to Garmin Connect.

Conclusion

For the dedicated swimmer, particularly in a pool environment, the Garmin HRM-Swim remains the top choice due to its specialized non-slip design and focused functionality. However, for the athlete seeking a comprehensive training solution across multiple disciplines, including swimming, running, and cycling, the Garmin HRM-Pro Plus offers unparalleled versatility, advanced metrics, and broad connectivity, making it the more robust and future-proof investment. Evaluate your primary activities and training goals to determine which Garmin HRM aligns best with your aquatic and overall fitness journey.