CFTs and HRMs

Out of curiosity I wore an HRM this morning when I was doing a CFT. Since it was the first one with a full load for a while it was ......interesting.

One thing I noticed was that my heart rate changed depending on how I adjusted the straps on my bergan. In fact there was a difference of nearly 20 BPM depending on how the bergan sat on my back.

I was actually quite surprised that it should make so much difference. Has anyone else tried using an HRM on a CFT? If so did you notice anything similar?

T_T

 

I've used an HRM with a civvie rucksack (no metal in the construction) on my back, and didn't notice anything.

Either the metal in the frame is affecting the signal (possible) or the straps are restricting your chest and hence the operation of your heart (unlikely - as you didn't comment about passing out half way round).

I would guess that it is down to the way in which the monitor sits on your chest. My monitor is semi-rigid and if I don't tighten the strap correctly, the electrodes do not sit on my chest, and I get a false reading. Try loosening the strap and running on a machine with the monitor bouncing on your chest, and see what happens. I reckon it will under-read because it isn't picking up every beat, but it will pick up enough beats to keep it happy - especially when you are on full chat (170-190bpm).

Litotes

 

And if you had enough time and energy to worry about your HRM on a CFT, TT, you are either super-fit or you weren't trying hard enough! LOL!

All I worry about on a CFT is staying upright and putting one foot in front of the other!

Litotes

 

Allowing your chest to expand more will increase the venous return to the heart, increasing the force and rate of contraction. How much this is affeced by tightening/loosening your bergen straps is a matter for debate. What would be interesting would be to monitor your respiratory rate and tidal volume along with your heart rate and 'bergan tightness'. You'd need to be hooked up to some machines on a treadmill though.