735XT heart rate monitor accuracy vs. 630

First things first. The 220-age formula is meaningless so don't judge the number you got from a device that was actually measuring your HR based on it and 196 is a pretty reasonable number for someone your age.

Now when it comes to optical HR vs chest strap it works well for some people and not so well for others. Optical works well for me but there are still some downsides to the tech in that it has more lag picking up changes during interval workouts and there's always the chance of getting cadence lock.

While there aren't as many possibilities for things to go wrong with a chest strap it's not an infallible technology either and there are many stories of static from shorts causing spikes when the air is dry, and the strap sliding down when the humidity is high, getting bad data when the battery is getting low... You get the idea.

If you got to 196 once, presume you have also had some runs where HR got into the 190s?

If not the the 196 maybe wrong. Was it actually a maximal effort? Hill reps I usually find a good way of getting a very high HR.

Otherwise agree the optical works well for some people. Seems to work fairly well for me although I prefer a strap as it does give the best accuracy for me plus of course you will miss all the running dynamic data without one.

My advice to you would be to try a watch with optical heart rate sensor before investing, it's not like your coming from a low end watch. If you're a runner, you don't really gain anything over the 630 with the 735 apart from the heart rate monitor. As R_Tellis said, the performance of the sensor varies from person to person, for me unless I am completely still, the readings I get from it are absolute garbage. Whist sitting, sleeping and on the turbo trainer it's pretty much spot on, any other kind of movement and the watch would rather display any other metric other than my heart rate.

If you got to 196 once, presume you have also had some runs where HR got into the 190s?

If not the the 196 maybe wrong. Was it actually a maximal effort? Hill reps I usually find a good way of getting a very high HR.

Otherwise agree the optical works well for some people. Seems to work fairly well for me although I prefer a strap as it does give the best accuracy for me plus of course you will miss all the running dynamic data without one.

It was at the end of a marathon last week, and I was running at 7:20min/mile pace up a hill so I'm not surprised if it was 194.

I haven't had it that high recently, although when I first started using the 630 when it first came out, I remember getting 199 during a Parkrun. I'm not sure if recent updates have improved the accuracy of the HRM. Perhaps I just have a naturally high heart rate, although my resting heart rate is 48.

Scott

I have the 735XT, 2nd watch now as I gave the first one back due to frustration with the OHRM.

My advice is dont even consider the 735XT if you are thinking about getting a vague idea of what your heart rate is from its optical sensor.
I'm 32 years old as well, weigh in at 75kg, dont have very dark or light skin, dont have much arm hair so no real physical reasons the OHRM should not work. I've tried everything with the position tightness... bla bla of the watch and am lucky to get 15 minutes of decent readings in a 1 hour work out.

Yesterday I went for a 2 hour cycle on the road. All the metrics it picked up were great... other than the heart rate. Averaged 119BPM supposedly and never really went over 125BPM. With a decent heart rate monitor my HR would probably peak on some of the hills at 185BPM and average 158BPM for the ride.

Thats my advice as for the price one pays for the watch to justify then having to purchase a heart rate strap on top of that due to poor readings from the OHRM is a touch usless. (even the resting heart rate I dont quite trust...)

If they could remove the OHRM and add a tri-strap for the same price call it a "730XT" I would call that watch pretty close to perfect.

For me, I can say the OHRM has been working quite well for my runs. I mainly used it for running only. I have done some testing against my HRM-run and Viiiva HRM strap and the bpm are really only within a couple of bpm apart. At least for me if I doing any long steady or interval runs I can trust that the OHRM is accurate enough for me. For short intervals I would still opt for the chest strap. It's nice to not have to wear a chest strap on long runs.