You are lucky to get it to work at rest. If my HR is 80 the Garmin says 40, if the HR is 40, the Garmin reads 80. If you are serious about using HR I still suggest a chest strap still. I know they can be a PITA too, and need replacing but I really like the Wahoo Tickr that has a flashing dot to at least identify if it is on, working, and sending a signal. Really helps determine if it is a connection issue or another corroded battery / strap.

---

---

Save: $50 on Speed Hound Recovery Boots | $20 on Air Relax| $100 on Normatec| 15% on Most Absorbable Magnesium

Blogs: Best CHEAP Zwift / Bike Trainer Desk | Theragun G3 vs $140 Bivi Percussive Massager | Normatec Pulse 2.0 vs Normatec Pulse | Speed Hound vs Normatec | Air Relax vs Normatec | Q1 2018 Blood Test Results | | Why HED JET+ Is The BEST value wheelset

Thomas above is the second person in as many days to lament on the Fenix optical HR sensor. My 935 works like a champion, day and night, and my 735 was excellent as well.

The heart rate sensor in my 935 works great as well. The only issues I've encountered are when I sweat A LOT, and then it does seem to read inaccurately.

I use the 735 and I would put it at about 85-90% in terms of accuracy...

I still have problems with "cadence lock" once in a while. Both on the bike and running...
And there are times when it's just goofy and there's no rhyme or reason to what it's reading.

Overall, I like the functionality. I'm just not 100% sold on the reliability and accuracy

---

"Good genes are not a requirement, just the obsession to beat ones brains out daily"...the Griz

If you are looking for a HRM and don't want a chest strap I suggest the Scosche Rhythm 24. It is an optical HRM that I wear on my forearm and it works like a charm. It is really comfortable and reliable. I don't trust my Fenix 5 HR to use it during working out. I tried one time and it was not that great.

I haven't followed up but make sure the production issues with the Scosche 24 have been fixed. Lots of issues, mine broke last summer. I still like the Scosche rhythm model, even though I lost it at a race. I'd buy one again, but currently using the wahoo tickr fit for longer battery life. Works great (I know for the OP it's a PITA when the Fenix should already work...)

wahoo tickr x hrm strap is 20% off on clevertraining

My guess is that it's wrist dependent.

I have a Vivoactive 3. It's accurate while sitting, standing, or generally not moving. Sort of okay when walking. I've given up on the HR sensor for workouts though. I've had times where it reads 90 bpm where it should be reading closer to 165+. Then it sort of reads close (+-3%), then suddenly it's way off again. Luckily for me, I didn't really buy it to track HR on it's own.

The Polar OH1 works great, and I believe the new ones are shipping with ANT+ compatibility.

I wear it on my upper arm and it is super reliable, even in the water. It has a stand alone recording mode since Bluetooth and ANT+ won't transmit underwater.

Skinny wrists. 935 is trash for me. Scosche worked on forearm or bicep until it went wonky after a few months. Wahoo band is the best and I've had less issues with it than a chest strap.

Honestly, the optical sensors are all pretty similar in all units.

It's the fit and snugness of the sensor on your wrist or forearm that makes all the difference. This is why the older Scosche Rhythm+ can outperform nearly all the other units.

I have had no problems with my 935. When I am doing sport I make the band tighter than normal to ensure I get a good HR reading.

This has meant that I have not used my Scosche HR for 6+ months. The Scosche (original version) worked perfectly for me either high on my forearm or on the bicep.

The optical heart rate on my Apple Watch is more reliable than my Garmin.

My Garmin Fenix 5x Plus HR has worked perfectly for me, as did the Fenix 3HR before it. I guess I’m the only one who had literally dozens of workouts with useless HR data from chest straps due to static electricity, shitty straps, voodoo, whatever. Anyway to answer your question, Scosche Rhythm+ on your forearm. Problem solved.

Thanks for all the replies.

It seems the Scosche is worth trying then.

But what about other watches? I like the idea of having one device rather than an external HR sensor be it chest strap or something like the Scosche on the arm.

Is there a difference in the HR sensor design between the Fenix and the 935 so it would be worth trying that one instead?

That could describe me as well...my 735 has worked well in the few years I've had it for everything from easy running to short sharp efforts that it might struggle with. It's had the odd hiccup but in fairness probably fewer than I had with various Garmin HR straps which regularly had erroneous high readings at the start of sessions despite damping the connections.

I use a Scosche rhythm+ indoors for the bluetooth connection but I've no complaints about the 735.

I have the garmin 735; hr readings are ok on the bike (match with edge and hr strap) and almost useless when running

My Vivoactive 3 is:
1) accurate at rest
2) fairly accurate when running
3) not accurate at all when on the trainer

For the life of me, I cannot explain 2 vs. 3. When on the trainer, it simply never catches up to my HR, often reading 40-50bpm low. The only real difference is my arm is mostly stationary when on the trainer, vs. obviously not when running.

One of the advantages of the Scosche is the ability to position it where it works best. A watch won't allow that.

I've had a Scosche Rhythm+ for 3 years. I wasn't overly impressed for the first few weeks I had it due to getting some erroneous readings and a few dropouts. However, when I moved it from the recommended location just below the elbow to the front of my upper arm just above the bicep, it became highly reliable. I've used it in that position ever since and it's been pretty bulletproof. Initially I used it for runs and stuck with the chest strap for the bike, but soon enough I was letting the chest strap gather dust. The data is fairly indistinguishable between the two. The optical has a bit more lag to changes in HR but it's not dramatic and it's also not really important for endurance training.

The Scosche Rhythm+ has 2 minor problems and that's about it:

• Battery life is only something like 7hrs
• Velcro strap can be annoying under clothing

The newer Scosche 24 version addresses both of these and adds a lot of new functionality such as built in data recording but is also slightly more expensive and seems to have had some quality issues on early examples (might be sorted out now). I wouldn't go back to a chest strap, especially for running. I just find them too uncomfortable. A watch alone would be great if it worked well, but it seems they need to be very tight on the wrist to work well and many have issues even then.

Look at the Polar OH1+, supposedly the most accurate.

https://www.dcrainmaker.com/...wahoo-tickr-fit.html

Cody Miller was raving about the optical sensor on the Phlex Swim (it sits on the temple). Mine is coming in the first batch.

So many delays but the beta testing appears to be going well.

---

___________________________________________
http://en.wikipedia.org/...eoesophageal_fistula
http://en.wikipedia.org/wiki/Cerebral_palsy
2020 National Masters Champion - M40-44 - 400m IM
Canadian Record Holder 35-39M & 40-44M - 200 m Butterfly (LCM)

The Polar OH1+ comes with a swim goggle strap clip that places the sensor on the temple also.

Mine has worked well on my upper arm.

The fenix works ok for me, but can be off a bit due to wrist angles (esp. when riding out of the saddle).

I have a MIO Link (similar to the Scoshe and the Wahoo), and just place the "puck" under my bike shorts on my quad. Reads fine, and is more consistent.

---

ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

I've been lucky with my 24. No problems besides a few brief cadence locks over the 8 months I've used it. It also works in the water paired with my Suunto ambit 3. It picks up your HR whenever your arm is out of the water.

Thx again.

But am I the only one that thinks it’s strange that Garmin can continue to market their watches as having advanced optical HR sensors when obviously they do not work for quite a few people?

Great if someone from Garmin could weigh in here.

Again, it doesn't matter how good the optical sensor is if the contact on the skin point is suboptimal. This is why the flexiband that Scosche uses allows their older sensor to outperform modern Garmin watches which have a more up to date optical sensor, but due to the form factor of the watch and the thicker band, sometimes don't maintain a great optical contact zone on certain wrists with certain activities.

The Scosche band is soft, pliable, and can be put in the best spot possible for consistent readings. It's more about the band and sensor placement than the sensor unit itself right now.

Happy 5S owner here. I had read varying reports and so was a bit sceptical of the optical accuracy when I got it so I compared the optical readings vs HR strap and my 1030 when I first got the Fenix and it was spot on. So much so that I don’t bother with HR straps any more. Sorry, not what you wanted to hear...😏

This is my exact experience with my 935. It's hilariously low on the trainer.

So a more flexible band would go a long way to solving the problem? Sounds too good to be true to me. Why would Garmin then not provide that as an option at least?

I have tried wearing the watch super tight, not so tight, right arm, left arm etc but no success.
But I will definitely try the Scosche.

But as I am now returning my Fenix what watch should I get that has similar features but does not make me pay the money and battery drainage of the (for me) useless optical HR?

Yes, that is exactly what I'm saying - a more flexible, more snugly fitting band makes all the difference. Note that the Scosche CPU portion is smaller than the Garmin watches as well so it'll also fit more snugly than the Garmin does.

Instead of ditching your Fenix, you could do what nearly everyone else who is serious about HR does, and use either a chest strap or a good wrist/forearm band like the Scosche to send HR data to the Fenix.

It's easy enough to order a Scosche Rhythm+ on Amazon and try it out and just return if you don't like it. Again, location of placement is key with the Scosche and all bands - note that the Scosche does NOT work well on the wrist if worn like a watch, it only works if you put it in the forearm or for some, the biceps area. I'd bet the Garmin would do even better if it could be placed there with the same form factor, as it's got a more up to date optical sensor. But the Rhythm+ sensor is so good when placed correctly that a better sensor wouldn't even help it in my case.

I don't think anyone is questioning the reliability of the measurement. Both my Garmin and Apple watches are reliable at providing numbers that purportedly relate to my beating heart. However, neither will give me accurate numbers when undertaking 'active' activities. Great for rest and easy walking, but anything else? The numbers produced are just that, numbers.

---

Trust me I’m a doctor!
Well, I have a PhD :-)

 The numbers I’ve gotten on my Apple Watch seem very reasonable given what I’ve seen from a Wahoo chest strap for similar rate of exertion. This is for running, cycling, even swimming.

I am one of the lucky ones that gets bang-on accuracy from my Felix 5s, unless the temps drop below about 35 degrees or so, then it can get pretty spotty. Like many others, I also recommend the scosche (I have the ‘24’ model). I use it on the trainer, and when the temps drop really low I use it to broadcast to the Felix. I honestly got the scosche as an all-in-one Bluetooth HR + pace unit to use for Zwift treadmill running while traveling, but my experience has been that the pace it broadcasts is for sh*t. I use it on my forearm, but maybe if I move it to my bicep the pace would work better...

When I did my research last year on buying a optical hr watch I pretty much found that they work great when at rest, when your actually doing something active they are worthless and you should be wearing a strap. The technology isn't here: when you get a nice layer of sweat between the sensor and your skin, it is much harder to read your HR.

I'm sure there are more knowledgeable people on here than me, but that is what I found and also based on my experience.

I’m fully in the polar eco system so have little to compare to, but I have zero complaints on my OH1 (now upgraded to a OH1 plus).

I pick it up in preference to my chest strap (was a H7, now replaced with a H10).

Before upgrading my OH1 to a OH1 plus, I read this which you may also find interesting :
https://www.google.co.uk/...epth-review.html/amp

WD :-)

Hello Swede and All,

Thinking about getting a Garmin Fenix 5.

With the watch heart rate sensor turned off does it work ok with a chest strap for sensing heart rate?

Is battery life better for watch with HRM sensor turned off?

---

Cheers, Neal

+1 mph Faster

I have the Fenix 5 plus. The optical is novel and I use it just to compare against itself, but no I dont think its accurate in the real number.

When I really want to know the real number I wear a chest strap.

I like the watch, but then I tried on my wifes apple watch, so much nicer and lighter... but not for triathlon and hate the idea of charging it that much...so I am back to enjoying my Fenix 5 plus. It works great for IM.

My 5s gives me great results unless I'm cross country skiing. Even if I wear it completely under my clothes so it doesn't get interfered with, the numbers are still about 2/3 of what they should be. I have to wear a chest strap for skiing 100% of the time. For running and cycling, it's spot on when I've compared it to the Polar that was replaced by the 5s.

I think this is all quite variable to the person.

Garmin 935 works great on me. Intervals, fast, slow, whatever, it’s pretty darn good.

Mio Link is great but not as good as the 935

Schoche rhythm plus, despite the accolades, was terrible on me, at least for running. It loved to cadence lock over and over, every single run.

Garmin modern straps are great on me.

Wahoo TICKR is horrible and almost never finds the correct HR even with electrode gel and the snap is so weak it falls off every time I adjust it.

To each their own.

Where did you wear your Scosche?

Upper arm inside and outside, wrist inside and outside., upper forearm inside and out. None of them worked for me

That sucks, bummer. For me, upper inner forearm is the only place that works for both Bike/run, but works extremely well. Better than chest straps.