Wrist HRM useless when cycling?

> Is there any trick to get the wrist-hrm to produce more accurate data?

Place it further up the wrist than normal (I go about one watch width) and have it quite tight so does not move at all.

No Pro...

blems here

Nope Really, I have never had a problem with the 735xt, I do wear it tight and it's worn just above the Ulna (Google it, I had to!)

I get the same issues with usless low HR readings.

What I have noticed is dont use any custom workouts... I made one, called it 'Cardio' for a general gym workout where I would do a 20min spin, 20min run, 10min row and some weights. If I would get a max of 130 and an average of 100 it would be amazing. The wifes Polar H7 for the same workout 156 average.
So if its an indoor run, select indoor run, or cycle select cycle.

I've tried super tight, tight, lose, low on wrist high, other wrist... there is no major difference to the readings for me.

The 735xt for me seems to think its clever and tries to use speed and other external measurements to give a heart rate, not just the sensor(or at least thats what I have come to believe from my own experience).
I've tested this on a few occasions. Basically in the gym, if I run and hold the side so my wrist does not move much, the heart rate drops below 100. When I run normally, it picks up the wrist movement and the heart rate gets to something more believable.
The same thing with getting on a spinning bike for an hour with minimal wrist movement... you guessed it low low readings...
Where the pattern became clear, is I got onto a WATT bike in the gym, and paired the power, speed and cadence ANT to the watch. Boom heart rate readings fine and also all the other awesome data.

Out doors training for me does not seem to be a problem (ok, I dont do much of it), but cycling with the GPS, the HR seems reasonable.

Interesting theory! Have you got any GC example links where running "normally" and not moving your wrist effected HR?

Of course on a Wattbike, your arm isn't going to be moving at all most of the time. Maybe you could jump onto the bike next to it (if there is one?) without pairing power etc and see if the HR is any different. TBH I would find this correlation unlikely. I can quite happily pedal on a Wattbike at say 100-150W at 2 digit HR for a while.

OHR is totally useless. It gives me approximately 30 bpm less than it should during runs. This makes me question how well my detected RHR is.

Interesting theory! Have you got any GC example links where running "normally" and not moving your wrist effected HR?

Of course on a Wattbike, your arm isn't going to be moving at all most of the time. Maybe you could jump onto the bike next to it (if there is one?) without pairing power etc and see if the HR is any different. TBH I would find this correlation unlikely. I can quite happily pedal on a Wattbike at say 100-150W at 2 digit HR for a while.

sheesh, 2 digit HR, I'm still trying to get to that level :p not there yet but I'm working towards it. I'm good for a heavy spin for 30min or so then I'm broken.

Here is my usual workout. 20min hard spin, 20min hard run, 20min crossfit type cardio (its hard for me :o )
https://connect.garmin.com/modern/activity/1316811600
Normally my heart rate is up at 160 within 10min and hovers between 150 and 188 for the rest of the workout. So you can see the heart rate spikes more when the wrist is moving more.

Here is a ride on the WATT bike ( :cool: love all the stats)
https://connect.garmin.com/modern/activity/1342539146
HR still a little confused for 10min then it was spot on.

Here is a 45min spin class
https://connect.garmin.com/modern/activity/1305944174
I would like to think I'm that good, but it was a tough session

Here is my latest road ride. I'll get faster one day :p
https://connect.garmin.com/modern/activity/1387412965
But reasonable readings I think.

I have the same issue.
I wear the watches tight, and in right position.

During cycle exercises, watches show me constant heart rate for about 100 or 120 bpm with low fluctuations.
It doesn't matter whether i ride uphill or do interval sprints – whist based HR is always around 120.

Here is an example of similar exercise recorded with the HRM-run chest strap, and wrist-based monitor.
Route, profile, and speed are almost the same. Difference between these tracks is one week.