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My favourite kit and nutrition
- Injinji – Runners protect your toes. Avoid discomfort and minor injury. Run more. run faster. I use them.
- Garmin 90-degree charging adapter — the small adapter that keeps your charging cable tidy at the stem. Essential for race day. I use one.
- Garmin charging puck — the fastest and most reliable way to top up your Garmin before a session. I use one.
- Ravemen FR300 — front light that mounts directly under your Garmin or Wahoo head unit. Keeps your bars clean and your beam pointed where it matters. I use one.
- Body Glide – The Blue anti-chafe stick that all swimmers and many runners use. I use it.
- Maurten — the race nutrition trusted by elite athletes. Gels and drink mix engineered to be easy on the stomach. I use them.
- Garmin Varia RTL515 — radar rear light that alerts you to vehicles approaching from behind. Pairs with your Edge or Garmin watch. I use this model.
- Favero Assioma Pro RS2 — the power meter pedals most serious cyclists end up choosing. Accurate, easy to move between bikes. I use this model.
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tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. ID
What about Garmin chest straps? Do they work for HRV
As per the article, check my HRM 600 review. There were issues I found on that (n=1). if you ask the scientists they will say they use Polar.
But this is just about the health snapshot feature. The HRV reading Garmin uses internally for training and health metrics is overnight HRV, where it is dark and people lay mostly still. The two can hardly be compared to each other
so you are happy with an overnight metric that assesses resting physiology and not exercise physiology? ;-). This should cover everything you need to know about HRV for sports https://the5krunner.com/2025/05/20/hrv-everything-you-need-to-know-garmin-whoop-oura-hrv-hrv4training-training-readiness/ . it contains a lot of things a lot of people want to sweep under the rug and ignore.
Yeah, and stuff like Body Battery during the day. Even if it’s pretty noisy over a short snapshot, the real question is how good is it over 24 hours?
I’d never use an optical sensor for taking a single, daily reading to record on my log, but after many years, I have come to find that Garmin’s HRV based metrics feel generally in the ballpark, as long as I’m wearing the watch regularly. Though, I’ll admit that I’ve never actually modified my behavior based on anything it tells me, and these days I only wear a sports watch at night (and mostly just so I can have a vibration alarm in the morning to not wake my partner).
I’m not surprised at this finding. Garmin may be epically mediocre in this regard but I would be surprised if wrist oHR was clinically useful for HRV. Garmin doesn’t even really try to use HRV from the wrist except during sleep and then primarily surfaces a rolling 7-day average.
I have not seen and can’t find formal clinical testing of the HRM 600 or HRM 200 yet but previous generations of Garmin are not impressive. To be fair not that ECG HRM are even being tested formally. The Wahoo Trackr got good N=1 results from Quantified Scientist but I don’t find any formal papers published for that either.
Dr. Bruce Rogers documented testing Garmin chest straps on his muscleoxygentraining.com blog and he gave up on them. Also he shows that ANT+ capture has significantly more lost peaks and artifacts than data captured over Bluetooth. I think this is significantly due to low frequency sampling on ANT+ due to Garmin legacy decisions to limit processing power for devices from the dawn of time.
Here is a formal study which finds 84-87% peak R-R peak detection at rest with Garmin HRM-Pro relative to a clinical control.
https://doi.org/10.3390/s24175713
Consistently the best available ECG chest strap is the Movesense Medical 💸💸💸 (€350 for a bare sensor and another €25 for the strap!) or slightly less good and affordable is the Polar H10.
Finally ! Someone who has been looking in the right places.
Yes Brian to all the above.
I don’t know why there is no clinical testing of the hrm600. My own n=1 tests with hrm600 showed hrv ‘discrepencies’ https://the5krunner.com/2025/06/11/garmin-hrm-600-review-best-heart-rate-monitor-hrm/. maybe that’s why. not sure of the incentive for scinetists to validate garmin devices for the comapny unless paid by the company to do so. that creates other problems with the findings of course.
And also the “running dynamics” are very noisy. I found exactly one lab test of Garmin running dynamics and the quality is very poor.
I looked into this after discussing with my DPT about using GCT balance to monitor recovery from injury. It seemed like a good idea. However when I actually tried it the numbers seemed far too good to be believable because I got something like 49-51 with a notably lopsided, wonky gait. It turns out this metric is trash. It’s almost totally noise and not fit for purpose.
https://www.mdpi.com/1424-8220/24/9/2892
Key findings
– Univariate overlap between in-lab and real-world data from the same runner ranged from 65.7% (leg stiffness) to 95.2% (speed).
– When all five gait metrics were considered together using multivariate depth analysis, only 32.5% of real-world data were well-represented by that same runner’s in-lab data. For ten subjects, overlap was less than 10%.
– Restricting real-world data to flat, straight segments changed overlap by less than 5 percentage points, meaning turns and hills were not the primary driver of the mismatch.
– Pooling in-lab data across many runners improved depth overlap to approximately 89–91%, because the broader cross-subject variability better captured real-world gait patterns.
I think this one has a supplemental table which shows r=0.12 on Garmin chest strap L-R GCT balance (or 88% noise). Garmin chest strap r=0.63 for vertical oscillation.
r=0.99+ for speed and step length. These sensors are reasonably good at speed, stance time, and cadence. The rest of running dynamics metrics are dubious.
I’m not convinced there is anything useful in the fancy running dynamics that you get from a Garmin-branded HRM-Run, Tri, Pro, 600 and the primary ECG data is also less clean than Polar H10. There aren’t a lot of good reasons to use the HRM-Pro et al, IMO.
Garmin running dynamics graphs are for entertainment purposes only.
test
For me, the Polar H10 is the worst chest strap I have ever used in my entire life. I would not use any Polar device even if they offered it to me free of charge. Here is my experience:
https://www.reddit.com/r/Polarfitness/comments/1qynbr1/can_polar_h10_be_a_guinness_world_record_candidate/
https://www.reddit.com/r/Polarfitness/comments/1recon3/brand_reputation_matters_my_polar_vs_garmin/
And I really wonder why people test older-gen Garmin optical sensors. Why do they measure Gen 4 instead of Gen 5 ?
IDK why they use the old sensors. This isn’t too bad. There must be a delay of 1-2 years from inception/planning to writing it up but even that wont quite explain it. gen 5 was available but on more expnsive models.
Garmin would perhaps give some studies free devices if they asked.
I had to switch from my Forerunner 255 to the Huawei Runner 2 because the heart rate readings were completely inaccurate. Additionally, it stopped correctly counting floors.
For some reason its not letting me respond to individual posts:
Brian:
Wahoo’s chest straps have been considered poor for r-r timing and so not useful for Alpha 1 dfa.
Ant+ is not worse then Bluetooth for r-r timing in terms of protocal. Ant+ is worse if you use r-r timing straight from Garmin as it doesn’t se what is in the protocal to make up for missing packets of data (when garmin records rr timing data in the fit file they hit this bug so doesn’t have good data). This can be overcome if you make your own raw connection (see alphaHRV connectIq app discussions) Garmin could fix this if they wanted.
I really wish review sites looked at rr data. If you want the easy way to do so look at alpha 1 dfa values which depend on that data so if the data is poor i will be easy to see. It bugs me how some sites spend lots of effort to compare HR data between devices but ignore rr data
i put a test comment above to brian. seems to work? I agree the box you have to fill in appears at the end of all the comments as you are typing but then the comment should be placed in the correct place on enter?
I agree HRV is not looked at by reviewers – I did here https://the5krunner.com/2026/01/13/garmin-hrm-600-replacement-accuracy-issues/ maybe I will do more.