I’m seeing weird results with my heart rate strap. My ground contact time is really low, but my vertical oscillation is really high! One indicates good form, the other indicates bad form. My subjective experience is that my vertical oscillation is low, but my garmin disagrees.
And I think the reason why is the movement of my breasts. I think they’re moving the sensor itself, and confusing its measurements.
Is that actually a thing? I’ve tried to find research or people talking about it, but all I can find is discussion on the impact of breasts on actual running performance, rather than on the measurement of it.
On really long races with a backpack, my HRM strap has often got nudged down so it’s practically round my abdomen, and it still worked fine. Why don’t you give it a go much lower and see what happens? That might help settle the breast question?
Can’t hurt to try I guess! I’ll give it a go
You could also try tightening the band a small amount to see if that reduces the oscillation measurement. You could also take a video of yourself running to confirm or deny what the strap is saying about your form.