Is the Amazfit Helio Strap a good value compared to other trackers?

The Amazfit Helio Strap offers a significant value proposition by eliminating recurring subscription fees, which is a major advantage over competitors like the Whoop Strap. This makes it a much cheaper long-term option, especially for users who want high-quality tracking without ongoing costs.

How accurate is its heart rate tracking, and where should I wear it?

Its heart rate tracking is exceptionally accurate, achieving high correlations with professional reference devices like the Polar H10 across various activities. For optimal performance, the reviewer strongly recommends wearing the strap on the biceps, as wrist-wearing noticeably reduces accuracy in his testing.

Does the Amazfit Helio Strap perform better than the Whoop Strap?

Based on the reviewer's scientific testing, the Amazfit Helio Strap often outperforms the Whoop Strap in heart rate tracking across indoor cycling, running, and outdoor cycling when both are worn on the biceps. It consistently shows higher correlations and fewer deviations, positioning it as a superior tracker in these specific heart rate scenarios.

Has the sleep tracking improved, and is it reliable?

Yes, the reviewer noted that Amazfit has made significant improvements to its sleep stage tracking since early 2025, and his initial tests showed enhanced performance with the special edition. While the specifics of REM sleep tracking were not fully detailed, the general sleep stage tracking appears to be more reliable now.

How well does it track heart rate during intense activities like outdoor cycling or weightlifting?

For outdoor cycling, which is a challenging activity for many devices, the Helio Strap performed "really good," with a correlation of 0.96-0.97. During weightlifting, it generally detected most heart rate peaks better than competitors, although some individual peaks might still be missed compared to an ECG chest strap.

The Quantified Scientist's Amazfit Helio Strap Review

Amazfit · Electronics · Reviewed by The Quantified Scientist · Published 2026-02-04

Rating 4.5/5Source quality 75/100Evidence 15Claims 8Q&A 5Pros 6Cons 4Electronics

Based on a review by The Quantified Scientist (accessed 2026-02-04).

This page converts The Quantified Scientist's review of the Amazfit Amazfit Helio Strap into structured evidence — timestamped claims, pros & cons, and buyer questions. It is not the original review and does not replace watching or reading the full source.

Product Evidence hub pending. This is currently the only analysed source for this product. A full evidence hub becomes available once a second qualifying source is processed.

Sponsorship & disclosure

Brand relationship disclosed as: affiliate

Source verdict

The reviewer concludes that the Amazfit Helio Strap is an objectively better heart rate tracker than many competitors, including the Whoop Strap, especially when worn on the bicep. While it performs very well for deep and light sleep tracking, it still struggles with accurately detecting REM sleep.

About this source

This review provides a scientific analysis of the Amazfit Helio Strap's heart rate and sleep stage tracking performance over two months. The reviewer, a post-doctoral scientist, compares the Helio Strap's accuracy against reference devices and other wearables across various activities like indoor cycling, running, outdoor cycling, and weightlifting.

Review notes

The Amazfit Helio Strap is a highly recommended alternative to the Whoop Strap, primarily due to its exceptional heart rate tracking accuracy and the absence of a recurring subscription. It consistently achieved near-perfect heart rate agreement with the Polar H10 reference during indoor cycling and running when worn on the biceps, often outperforming the Whoop Strap and Polar Loop. While some minor deviations occurred during outdoor cycling and a few peaks were missed in weightlifting, its overall performance significantly surpasses much of the competition. Additionally, sleep stage tracking has seen notable improvements from earlier 2025 versions. If you prioritize highly accurate heart rate data across diverse activities and seek to avoid subscription fees, this strap is an excellent choice, especially if worn on the biceps. However, if wrist-wearing convenience is paramount, its performance may be slightly compromised.

What the reviewer liked

No subscription fee, making it a cheaper alternative to Whoop.
Exceptional heart rate tracking accuracy for indoor cycling, running, outdoor cycling, and weightlifting.
Often outperforms Whoop Strap and Polar Loop in heart rate tracking across several activities when worn on the biceps.
Achieves very high correlation (e.g., 0.95 or higher) with reference heart rate monitors like Polar H10.
Improved sleep stage tracking compared to its earlier 2025 performance.
Maintains good performance even with some minor deviations during demanding activities like outdoor cycling and weightlifting.

What the reviewer criticised

Heart rate tracking performance is noticeably worse when worn on the wrist compared to the biceps.
Occasional minor deviations and brief signal loss observed during some outdoor cycling sessions.
Some heart rate peaks were missed during weightlifting sessions, though overall performance was still good.
REM sleep tracking's specific performance details were not fully elaborated, implying potential areas for improvement.

Structured claims

The Amazfit Helio Strap has become a popular and cheaper alternative to the Whoop Strap in 2025 because it does not require a subscription.

reviewer_claimstrong

The Amazfit Helio Strap provides high accuracy heart rate tracking during indoor cycling (spinning) when worn on the bicep, performing as well as leading smartwatches.

reviewer_claimstrong

The Amazfit Helio Strap provides high accuracy heart rate tracking during running when worn on the bicep, achieving a super high correlation and outperforming most other devices.

reviewer_claimstrong

The Amazfit Helio Strap provides high accuracy heart rate tracking during outdoor cycling when worn on the bicep, with a correlation of 0.96-0.97, making it one of the best trackers available.

reviewer_claimstrong

The Amazfit Helio Strap's heart rate tracking performance across all exercise types is significantly better when worn on the bicep, with wrist-wear generally yielding worse results.

reviewer_claimstrong

The Amazfit Helio Strap performs well for heart rate tracking during weightlifting, detecting most heart rate peaks, comparable to the Apple Watch, though some individual peaks are occasionally missed.

reviewer_claimmoderate

The Amazfit Helio Strap demonstrates good accuracy for tracking deep sleep (82% agreement) and light sleep (78% agreement) stages, but it struggles with accurately tracking REM sleep, showing only about 50% agreement with the reference device.

measurement_claimstrong

For the highest heart rate tracking reliability, an ECG chest strap connected to a sports watch is superior to optical trackers like the Amazfit Helio Strap, though the Helio Strap comes very close.

reviewer_claimstrong

Evidence items

Amazfit Helio Strap as Whoop Strap Alternative

reviewer_claimneutralt=00:00–00:15

The reviewer notes that the Amazfit Helio Strap has become a popular and cheaper alternative to the Whoop Strap in 2025, primarily because it does not require a subscription.