HELIOS 2.0 vs Garmin Fenix 8: which one actually protects a heart over 40?
I’m 48. Most cyclists my age already wear a Garmin and assume it’s looking after their heart. I wore a Fenix 8 against HELIOS 2.0 for twelve weeks to find out. Only one of them was still on at 3 a.m.
HELIOS 2.0 + THRIVERing + app + AI coach
Garmin Fenix 8SmartwatchThe quick verdict
- On 24/7: the world’s thinnest and lightest smart ring
- Tracks your sleep and strain every night, no gaps
- Plans your training load, nutrition and recovery together
- An AI coach with full context on all of it
- Records your rides and workouts
- Worn to bed about 1 night in 3
- Too bulky to sleep in, needs charging, doesn’t suit work or dinner
- So no full overnight picture of your heart or your recovery
- No plan for your training load, food or recovery
- Its numbers don’t talk to your plan
✓ 30-day money-back trial · 90-day results guarantee · Free shipping
Stock is limited: 100 HELIOS 2.0 rings this month
Why I ran this test
A mate’s heart scare, and a watch that never noticed anything
Last spring a man from my club, fitter than me and two years younger, was told after a scan that his heart wasn’t in the shape his legs were. He wore a top-end watch every ride. It had his power, his heart rate and his VO2 max. It didn’t have most of his nights, because he took it off to charge.
“Turns out I was in constant AFib and could’ve dropped dead at anytime over 2 years and had no idea. Thought I was doing great with my heart health.”
u/Burnt_Phoenix22 · r/Garmin, after an ablationIf anything feels wrong on the bike, see a doctor first. Neither device here diagnoses anything. What I wanted to know is which one does a better job of the four things you control: the load you put on your heart every week, your nutrition, your sleep and your strain. And whether anything watches all four together.
To be clear, the riding itself is good for your heart:
263,450 UK adults: people who cycled to work, against people who didn’t.
Celis-Morales et al. · BMJ · 2017 · observational, a link not proofAdults given treadmill fitness tests: the fittest against the least fit.
Mandsager et al. · JAMA Netw Open · 2018 · general populationSo the question was never whether to keep riding. It was what watches the four around it.
How I tested
- Twelve weeks with a Garmin Fenix 8 and HELIOS 2.0, side by side
- Same build block, same Saturday group ride, same job
- Scored on the four things you control: training load, nutrition, sleep and strain
- Plus one question: does anything put them together and tell you what to do?
Where the watch fell down
It only saw a third of my nights
This is the part nobody tells you. A watch can only track your heart and your recovery when it’s on you, and most of the time mine wasn’t. It was too bulky to sleep in, it needed charging most nights, and it didn’t suit work or dinner, so it came off.
Garmin Fenix 828 of 84 nightsHELIOS 2.084 of 84 nightsEach square is one night of my 12-week test. Filled = the device was on and tracking overnight.
That gap is the whole problem. The overnight readings are the ones that matter for your heart: resting heart rate, HRV, skin temperature and sleep, measured while you’re still. On the nights the watch sat on the charger, there were none. So its recovery score was built on two nights out of three it never saw, and it never had the full picture of my heart.
- Two in three nights of resting heart rate and HRV
- Most of my sleep, so its recovery score was a guess
- The slow climb in my resting heart rate over the block
- The night before the cold, when my temperature went up
- Every night: resting heart rate, HRV, skin temperature, sleep
- The trend over all 12 weeks, against my own baseline
- The cold coming, a day before I felt it
- All of it fed into one plan for training, food and recovery
Side by side
| HELIOS 2.0 + THRIVE | Garmin Fenix 8 | |
|---|---|---|
| Comfortable enough to wear 24/7 | ✓ | bulky in bed |
| Tracks your sleep every night | ✓ | about 1 night in 3 |
| Tracks your strain day and night | ✓ | if worn |
| Plans your training load each week | ✓ | suggestions |
| Plans your nutrition, counted in recovery | ✓ | log only |
| Moves the plan when you’re ill or run-down | ✓ | — |
| An AI coach that has full context on your training, nutrition and recovery | ✓ | — |
| All four on one plan, changing together | ✓ | — |
The road test
Three weeks that decided it
By week two I was doing what most people do with a watch: taking it off at bedtime, because it was charging or because it was annoying in bed.
Tuesday night I slept badly and didn’t think much of it. By Wednesday I had a scratchy throat and a big interval session on Thursday.
Recovery 45 · rest required · all four namedThe same kind of brief on a run-down morning: rest required, and why.
Session skipped · next one eased · tempo movedMARCO rebuilding the week around it.
Real THRIVE screens.
This is the part almost nobody tracks, and it decides whether a hard week turns into fitness or into a hole.
HELIOS 2.0 + THRIVE: all four watched together, and a plan that changes with them
A watch is sold on the wrist and the ride. It has to do everything on your arm, so it needs charging, and it’s too big to forget about in bed. None of them is built to plan your training, food and recovery as one system. THRIVE was built the other way round: the plan first, and the lightest ring we could make to keep it up to date.
✓ 30-day money-back trial · 90-day results guarantee · Free shipping
Stock is limited: 100 HELIOS 2.0 rings this month
Who should get which
- you’re over 40 and still riding hard
- your watch spends its nights on the charger
- nothing plans your food around your training
- you want one coach watching load, food, sleep and strain together
- you only want to record your rides
- you already plan your load, food and recovery yourself
- you wear it to bed every single night
Final scores
A heart that’s been ridden hard for 20 years almost never has one problem. It’s training load with no cap, food nobody plans, sleep nobody tracks properly, and strain nobody adds up. A watch covers the ride and the nights you remember to wear it. HELIOS 2.0 with the THRIVE app covers all four, every night, and one AI coach puts them together. Get your heart checked, then get the whole week watched.
The world’s thinnest, lightest, slimmest smart ring. Beautiful, and made to be worn 24/7 for every occasion.
The world’s slimmest and lightest smart ring: 2.0 mm thin, 6.5 mm wide and 2.1 g of matt black titanium, so it stays comfortable on the bike, at work and asleep. It fits under cycling gloves.
It comes off because it’s bulky in bed or on the bars, or because it needs charging, so whole nights and days go missing.
Typically pretty ugly, and not something you wear to work or to dinner, so it comes off and the gaps start again.
Thin and light enough to sleep and ride in, beautiful enough for work and dinner, and 7–10 days a charge, with 3–4 weeks more in the travel charger. It stays on.
“Stupid as it sounds, this is the first wearable I haven’t taken off in 6 weeks. No bulk, sits flat under my work glove, charges in 45 min.”
Owen Bartlett · Verified buyer✓ 30-day money-back trial · 90-day results guarantee · Free shipping
Stock is limited: 100 HELIOS 2.0 rings this month
How many more seasons will you ride hard on a heart nobody is watching?
The Saturday ride at 80
Ask cyclists over 40 what they want from the next 30 years and nobody names a number. They want to still be on the Saturday ride at 80, on the wheel up the climb everyone races. A week in the mountains at 65 without a second thought. Riding with their kids when the kids are finally fast enough to drop them, and not letting them.
That’s what the hard days are for. Trained, fed, slept on and watched, they build those years. Left to chance, season after season, they’re what puts them at risk.
Here’s what the setup most of us run costs. Each piece sees one of the four at most, and none of them sees them together.
US list prices, checked August 2026.
HELIOS 2.0 with travel charger + the THRIVE app
For readers of this article: your 90-day guarantee is set on your heart numbers, not your watts.
- HELIOS 2.0 titanium ring + travel charger2.1 g, 7–10 days a charge, 3–4 weeks more in the charger
- Sleep, tracked every nightResting heart rate, HRV, skin temperature and blood oxygen while you sleep
- Strain, tracked day and nightEvery ride, every workday, every stress
- Every day’s food set to your trainingCalories, carbs and protein, counted in your recovery
- A training plan that caps your hard daysReal easy days and strength, in phases
- MARCO, the AI coach watching all fourExplains every change, and moves the plan when you ask
- Your 90-day heart targetSet with our team after your first week of nights
Stock is limited: 100 HELIOS 2.0 rings this month
Get HELIOS 2.0 →✓ 30-day money-back trial · 90-day results guarantee · Free shipping
Try it for 30 days. Get results in 90, or your money back.
Wear it for 30 nights. Not for you? Send it back for a full refund.
Your target is set on your heart, with our team, after your first week of nights: for example, resting heart rate back at or under your own baseline by day 90. Miss it and we refund you in full.
Plus a 2-year warranty, free shipping and a free sizing kit before you commit.
Coaches, cyclists and clinicians
Nutritionist’s viewOliver, sports nutritionist10 years with endurance athletes▶ Watch Oliver’s video
Nutritionist’s viewLina SorensenSports nutritionist and endurance fuelling coach“Riders over 40 recover slower, and most plans ignore it. Seeing sleep and HRV each morning lets them fuel and rest for the body they have.”
“MARCO flagged ‘three days of suppressed HRV and elevated resting HR — recommend two days easy’. I ignored him, did the threshold workout, blew up. Now I listen.”
Camille Dufort · Verified buyer“MARCO kept me from blowing up at the wrong moment three different times across 28 hours of riding. Fueling reminders alone earned the subscription.”
Henrik Sørensen · Verified buyerBefore you buy
Is HELIOS 2.0 a medical device?
No. It doesn’t diagnose anything. If you have symptoms on the bike, see a doctor first. What it does is track you every night so the plan can change when you’re run-down.
Can I keep my watch?
You can wear what you like. HELIOS 2.0 and the THRIVE app do the job on their own: the ring tracks you 24/7 and your phone is the bike computer in ride mode.
Will I actually wear a ring every night?
That’s the point of it. It’s 2.0 mm thin and 2.1 g, the world’s thinnest and lightest smart ring, and it runs 7–10 days a charge, so there’s no nightly charger.
Can I keep my bike computer?
You can ride with what you like. HELIOS 2.0 and the THRIVE app do the job on their own, and every ride feeds the plan. When you want a ride screen, THRIVE’s ride mode has navigation and Climbing Mode.
What if it doesn’t suit me?
There’s a 30-day money-back trial, and a 90-day results guarantee.
So you’ve got two options
Keep a watch that records your rides and misses your nights, and hope your heart keeps up.
Put your training load, food, sleep and strain on one plan, watched every night, with 30 days to send it back.
✓ 30-day money-back trial · 90-day results guarantee · Free shipping
Stock is limited: 100 HELIOS 2.0 rings this month