In my quest to find out I got a Garmin premium chest-strap (2nd hand off Amazon, so for £20 rather than £35 although I fear it smells of someone else when it heats up!) because someone in net-land said that Polar heart-rate monitor chest-straps don't get a build up of static and the transmitter on the Garmin premium chest-strap can be snapped onto a Polar Wear Link chest-strap. Well the Polar chest-strap turned out not to give any different results from the Garmin chest-strap - but I was by now too deep into this to just forget about it. Another suggestion I'd read on-line was to use a conductive gel on the sensors rather than just water - and that you could use ultrasound gel rather than specifically gel for heart-rate monitors at a fraction of the cost. So I ordered up some ultrasound gel - and I used it yesterday. But then we drove all the way to North Berwick before we started running so I think the gel had dried up. I did get a heart-rate spike of over 180 but it didn't seem a fair test. So today I gelled up and out I went for an 8 miler.
The results are above. I got a brief reading of about 150ish, which back in the old days I wouldn't have blinked at. So there seems to be a change anyway, if not a complete answer to my questions. The other things suggested on-line are to only wear cotton t-shirts or to run bare chested. I'm not about to adopt either strategy.
It was a nice day but it was kind of a forced run as my Sunday runs seem to be these days. I was pretty knackered after yesterday. Arthur's Seat seemed to be teeming with Portuguese people this afternoon.