Ok, I’ve been experimenting and this is what I’ve found so far.
Firstly, it seems clear to me that the behaviour of the watch’s presentation of pace changes when a stryd pod is used so I’m pretty sure the pace data is used and is used in preference to in-watch fusedspeed data.
When I use the stryd pod, pace appears to be updated pretty consistently every 2 seconds or so. I actually think Suunto could do some work to tune this to improve it because my iPhone app (iSmoothRun) can update every second but that’s an aside. When the stryd is paired, no level of mucking about with gps or holding my arm to see the watch for extended periods makes any difference so I’m going to say when a stryd is paired fusedspeed isn’t used and pace comes from the stryd, not gps.
When not using the stryd pod I can def. create scenarios where I can tell the difference. With a recently sync’d watch, over 20% battery, performance level gps and a solid gps signal I actually think the watch updates pace faster than when using the stryd. However, not sync’ing before a run, having less than 20% battery and running deliberately where I know the GPS signal is weaker (under trees, along canals etc) the pace update rate drops significantly. Here it seems to update every 5 or so seconds and is also more likely to react to a slowing of pace than an acceleration. I’m guessing this is the frusedspeed stuff kicking in.
If I go further to ‘break’ the fusedspeed capability by holding my wrist up to view my watch continuously (therefore preventing the accelerometer from doing it’s job) then in a poor signal area the pace can easily freeze for 20 seconds or more until GPS catches up.
So my conclusion is that the watch adopts behaviour 1 from my original post. As a result I’m not going to be retiring my Stryd any time soon
And as a PS maybe Suunto could improve the refresh rate for pace and power from the stryd to every second
I’d be interested to hear if other people have different experiences
