Amazfit Helio Strap Review: A £100 Whoop Alternative With No Subscription

The Amazfit Helio Strap is one of the cheapest serious Whoop alternatives you can buy in the UK, and it leans further towards the gym than most screenless bands. It costs £99.99 on Amazon UK, it lasts up to 10 days, it counts your reps, and it charges you nothing after that. You can wear it on your wrist for sleep and move it to your upper arm for training, where it doubles as a heart rate strap for your watch or treadmill. The trade-off is the Zepp app, which is fine but nowhere near Whoop or Garmin for polish. If you lift, do HYROX or just want recovery numbers without a monthly bill, this is the one I'd buy.

Amazfit released it in June 2025, and the UK price hasn't moved much since. Amazfit's own store sells it for £99.90, so Amazon is effectively the same.

Check the Amazfit Helio Strap price on Amazon£99.99

What you actually get

The official Helio Strap page lists a small pod measuring 33.97 x 24.3 x 10.59 mm in a fibre-reinforced polymer shell, on a 22mm nylon strap with a hook and loop fastening. It weighs 20g and fits wrists from 145 to 205mm. There's no screen, no buttons to speak of and no GPS. A rotor motor handles vibration.

Inside is Amazfit's BioTracker 6.0 optical sensor (5 photodiodes and 2 LEDs), plus an accelerometer, gyroscope and temperature sensor. It records heart rate every second, all day, and stores up to 21 days of heart rate offline, which matters for team sports where your phone sits in a bag. Outdoor runs borrow your phone's GPS.

In the box you get the band with strap attached, a magnetic charging head and a manual. No USB-C cable, so you'll need your own.

One oddity: the Amazon listing says 110+ sports modes, while Amazfit's own spec sheet lists 57 and the product copy says 50+. I'd trust the manufacturer's spec page. It also helps to know what that list includes: strength training, HIIT, rowing machine, HYROX race, pool swimming and a long list of ball and combat sports.

Recovery tracking: BioCharge, sleep and HRV

This is the Whoop part of the job. Overnight the Helio Strap tracks sleep stages (including REM), naps over 20 minutes, sleep HRV, sleep breathing quality and a sleep score. Through the day it logs heart rate, blood oxygen and stress.

Amazfit rolls that into BioCharge, a morning energy score that drains through the day based on activity and stress. Its newer HybridCharge layer combines BioCharge with LifeLoad and Training Load to give you one number for how much you've got left. If you've used Garmin's Body Battery or Whoop's Recovery, you'll recognise the idea straight away. Our Amazfit Balance 3 review makes the same point: it's a familiar readiness score in Amazfit's packaging, and none the worse for that.

How far should you trust the sleep numbers? About as far as any wrist tracker. A 2024 systematic review in JMIR mHealth and uHealth found Fitbit, Garmin and Whoop devices were moderately accurate for total sleep time and weaker at splitting sleep into stages. The Helio Strap wasn't in that research. Treat your stage breakdown as a rough guide and watch the trend in total sleep and overnight HRV across weeks.

Training: arm wear, rep counting and HR broadcast

This is where the Helio Strap pulls ahead of most screenless bands. Amazfit designed it to sit on your upper arm during training using an armband extension, because gripping a bar or kettlebell changes blood flow at the wrist and throws optical sensors off.

The research backs the idea. A 2025 validation study in JMIR Cardio put Polar's arm-worn Verity Sense against an ECG chest strap across 9 activities, from lying down to HIIT. On the upper arm it averaged a mean absolute error of 1.43 bpm, while a wrist-worn Polar watch in the same study averaged 6.41 bpm. That's a different device from the Helio Strap, so it doesn't prove Amazfit's accuracy. It does show why the upper arm is the better spot for training.

On the arm it becomes a live heart rate source. Amazfit says it'll broadcast to its own watches, third-party smartwatches, treadmills, cycling computers and training apps. It connects over BLE only, so check your kit supports Bluetooth heart rate before you ditch your chest strap.

Strength training is the other selling point. Inside the Strength Training mode it auto-recognises 25 movements, including barbell squats, bench press, deadlift, pull-ups, lat pulldowns, bent over rows and bicep curls. It logs sets, reps and rest. Anything it doesn't recognise, you pick from a list in the Zepp app afterwards. There's also an official HYROX Race mode, plus VO2 max, training load, training effect and recovery time after each session.

Data syncs from Zepp to Strava, TrainingPeaks (via Terra), adidas Running, komoot, Relive, Apple Health and Google Fit. If you already own an Amazfit watch, the strap and watch share data so tracking carries on when one is on charge.

Helio Strap vs Whoop, Fitbit Air, Garmin Cirqa and Polar Loop

Whoop. Our WHOOP Peak review covers the membership model: roughly £229 for 12 months, and the band stops being useful when you stop paying. Whoop claims 14+ days of battery and has the more mature recovery coaching. Over two years you'd pay about £458 for Whoop against £99.99 for the Helio Strap. Unless Whoop's coaching is worth £350 to you, Amazfit wins.

Fitbit Air. The Google Fitbit Air costs £84.99, weighs 12g with its band and lasts up to 7 days. It's lighter and simpler, but its Gemini coaching sits behind Google Health Premium after a 3 month trial, and it has nothing like the Helio Strap's rep counting or heart rate broadcast. Pick the Air for sleep and steps, the Helio Strap for the gym.

Garmin Cirqa. Garmin's Cirqa band is £179, also subscription-free (Connect+ is optional) and also rated for up to 10 days. You get Body Battery, HRV status, skin temperature and Garmin Connect, which is the better app. It costs £79 more, and for lifters it doesn't offer the arm-wear and rep counting that make the Helio Strap stand out.

Polar Loop. The Polar Loop is £109 on Amazon UK, weighs 29g, lasts up to 8 days and gives you the free Polar Flow app with Nightly Recharge. It's a sleep and wellness band first. The Helio Strap gets more out of a training session for a tenner less.

For the full field, see our Whoop alternatives guide.

See the Amazfit Helio Strap on Amazon UK£99.99

Who should buy it

Buy the Helio Strap if you lift, do HYROX or circuits, and want recovery and readiness numbers without paying every month. It suits people who already wear an Amazfit watch and want tracking to carry on while the watch charges. It's also a good fit if you hate chest straps but want decent heart rate data on a treadmill or bike.

Skip it if you want to see the time or your heart rate on your wrist, or if you run outdoors without your phone. A GPS watch is the better tool there. Skip it too if you're deep in Garmin Connect, because the Cirqa will slot into your existing data far more neatly. And if sleep is your only interest, the Fitbit Air or Polar Loop does that job for less fuss. Our sleep and muscle recovery guide explains which overnight numbers are worth acting on.

Value and verdict

At £99.99 the Helio Strap undercuts the Cirqa by £79 and costs less than half of one year of Whoop. It still gives you the training tools most screenless bands skip. Its weaknesses are real: the Zepp app is functional rather than good, there's no cable in the box, and you'll want to confirm the armband is included before you count on bicep wear.

I'd give it 4.3 out of 5. It drops marks for the app and the packaging gaps, not for anything the hardware gets wrong.

Recommended reads

1. WHOOP Peak review
2. Google Fitbit Air review
3. Best Whoop alternatives
4. Amazfit Balance 3 review
5. Heart rate zone training explained