The recently announced Suunto Spartan ULTRA and then the very recently announced Suunto Spartan SPORT look like great products. Perhaps even market-leading products in their targetted segment.
Some great specs are on the Suunto site and, from a hardware perspective, it looks a superior bet to the Fenix 3, on paper at least.
However. There is always a HOWEVER or a BUT.
The Spartan SPORT announcement was ended with the reference to (OPTICAL) HR on the wrist by the end of the year.
Immediately I assumed they would have gone with MIO who have been very quiet on the optical front since there brief partnership with Garmin for the Forerunner 225. Garmin of course presumably used this as a stepping stone to their own ELEVATE optical technology. MIO put together a great hardware package with the MIO Link (review here) that remains a good optical HR wrist band even today.
Well it’s not them.
Then I thought of LIFEQ who have been very active. Recently they announced a partnership with Garmin and, of course, they are the optical powerhouse behind the hugely successful TomTom Runner2/SPARK (review here). Indeed, LIFEQ’s measurement solution is validated (here) and is generally pretty good in my experience.
Well it’s not them.
Then I thought they might have worked on their own. I dismissed that as unlikely.
And, indeed, that is the case. They did NOT do it themselves. Unlike Epson who had an awesome go with the Runsense SF810 (review here).
https://web.archive.org/web/20140208203028/https://valencell.com/sites/default/files/valencell_logo_72dpi_rgb.jpg
They went with VALENCELL (Source: dcrainmaker.com).
Ta Da!
Who?
Despair not dear Suunto lovers. That is, indeed, a super-wise choice. Even though you’ve probably never heard of them. The reason being that VALENCELL powers the Scosche RHYTHM (review here).
Now the Scosche RHYTHM is a sort-of wonderful thing. Once I even re-did one of my tests as the HR track from the Scosche PRECISELY matched the one from my chest strap. It was SO similar that I assumed that I had two devices BOTH RECORDING THE CHEST STRAP.
So the VALENCELL partnership does sound great and it is.
Some caveats though. Firstly the Scosche RHYTHM works on the upper arm which I believe is an intrinsically better and easier place to take HR readings optically. Having said that I’ve tried it on other parts of the body (don’t ask!) and it’s good. Secondly Suunto will have to integrate the sensor, if they do a bad job we will get bad HR results (unlikely, but I mention it anyway!).
Thirdly, apart from accuracy, there will be battery consumption issues. I’m not sure that many Suunto users want 247 non-HRV, optical HR monitoring which is only peripherally useful at best. And if Suunto have delivered 247 HR then the battery WILL take a hit. This could be a shame as ‘somehow’ Suunto seem to have delivered superior hardware onto the SPARTAN, certainly superior when compared to the screen resolution in the Fenix 3 whilst still matching or beating the F3’s battery levels. (Garmin Fenix 4 this year? 🙂 )
Remember that the optical HR sensor WILL lower the battery life when used for a sport as well – kinda obvious really, just not sure how much by.
Anyway. It’s probably a very good partnership and could well have been a WHOLE LOT worse with a different choice.
Related reading: Suunto Spartan Ultra Specs – *NEXT WEEK* for the more specifications.
Last Updated on 8 April 2026 by the5krunner
My favourite kit and nutrition
- Maurten — the race nutrition trusted by elite athletes. Gels and drink mix engineered to be easy on the stomach.
- Garmin 90-degree charging adapter — the small adapter that keeps your charging cable tidy at the stem. Essential for race day.
- Garmin charging puck — the fastest and most reliable way to top up your Garmin before a session.
- 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.
- Garmin Varia RTL515 — radar rear light that alerts you to vehicles approaching from behind. Pairs with your Edge or Garmin watch.
- Stryd — the footpod that brings running power to your Garmin. The single most useful running upgrade I have made.
- Favero Assioma Pro RS2 — the power meter pedals most serious cyclists end up choosing. Accurate, easy to move between bikes.
Reader-Powered Content
This content is not sponsored. It’s mostly me behind the labour of love, which is this site, and I appreciate everyone who supports it.
Support the site: Follow (free, fewer ads) · Subscribe (paid, ad-free) · Buy Me A Coffee ❤️
All articles are written by real people, fact-checked, and verified for originality. See the Editorial Policy. FTC: Affiliate Disclosure — some links pay commission. As an Amazon Associate, I earn from qualifying purchases.
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
“…HR on the wrist by the end of the year.”
End of which year? I ask since:
1) I’m a nerd
2) I asked my ISP if they have a migration plan for rolling out fiber and killing my current coper DSL pipe. They told me Q1, making me pop the question “Q1 of what year?” Sir, 2018, and not 2017Q1.”
I’ll note here that I had my Vo2Max tested at a hospital lab (I was curious, what can I say!), and wore my Schosche during the test, and it tracked the hospitals EKG readings nearly exactly. I was impressed. Granted that was inside on a treadmill, but it gave me lots of confidence in it.