It's very interesting to see what runners' heart rates are in real time as you watch a speedrun. I just watched the top time in its entirety for Super Mario Land for the Game Boy, Normal + Hard category, glitches allowed, which saw a heart rate bottom out around 70, shown all the way green, it became all the way red at a surprisingly low 90... especially since it got as high as 150 during 4-2 on Hard, indicating that was the most nerve-wracking level in the run, and it climbed higher than with victory, where a lot of people's heart rates seem to shoot up in games in general.
In fact, should I so much as beat the relatively slow time of 34:45 for Columns III, a puzzle game, on Hard, my own heart rate would probably peak there since sometimes, I wouldn't even be all that nervous during battle with the sphinx, and be shocked and delighted to win quickly causing my heart rate to skyrocket. So really, it all depends on the game as to where the heart rate peaks.
Two reasons I can think of for having it are (1) entertainment, to see how "nervous" players are during play, and (2) medical, in case players cannot climb above a certain heart rate without causing problems. I have no medical problems myself necessitating limiting this, so my own reason for showing mine would be for entertainment and insight into how "nervous" I am in real time during play.
Are there any verification reasons to have this, too, or some other reason? Or is it really just entertainment and maybe medical? Are there any real suspicions about runs being faked due to being unnaturally calm during segments the community for the game sees as nerve-wracking and hard, especially near the end?
My understanding is that it's just for entertainment, and that it was popularized by @darbian when he was setting records in smb1. Though perhaps someone who's been around longer can give more info.
I don't think its for medical reasons, its to show how nervous they are. The heart rate usually slowly climbs, and then spikes at the end of the run.
I do actually believe that this could serve as a helpful verification tool. As mentioned already, heart rate tends to spike at the climax of a run, when the runner is under maximum pressure, but in a case where the runner is cheating by playing back a spliced run, for instance, it stands to reason that they wouldn't undergo this sort of physiological change because they already know the outcome of the "run".
Not that this should become standardised, or a requirement to do runs. That would be a ridiculous requirement, but it is an interesting thought nonetheless.
and you really think when they play back a spliced run they don't also fake a heart rate on screen? lol