Have you ever noticed how much your heart rate soars when someone hot walks past? Or when you're watching a scary movie? Or how about the way it drops when you're falling asleep?
Sure, these fluctuations are hardly surprising. But watching and collecting these readings with an optical heart rate wearable can be addictive. And as I found it can be even more addictive than the regular way of using heart rate - to make your exercise stats more accurate or using heart rate training zones. And that's probably because it's inextricably tied to your emotions.
Your heart rate isn't just about fitness
Heart rate sensing devices in all shapes and sizes have been used to inform research for decades, from better understanding panic disorders through to providing ways to see how female sex hormones behave.
But over the past few years more consumer-facing trackers have also been used in a range of different settings, in a bid to prove just how scary or tense or exciting or sexually-charged something is.
The entertainment industry has been leading the way when it comes to shouting about this kind of data – which isn't surprising given its job is to market fear and excitement. There are countless examples here, but back in 2013 Play.com claimed it had figured out the most scary movie of all time was The Shining based on heart rate data. Then just last year the makers of The Revenant collected heart rate readings from audience members to show just how tense the storyline became.
Sporting events soon got in on the action too, when Jaguar and Wimbledon teamed up for Feel Wimbledon, which showed just how tense watching the back and forth on centre court can be.
All of these applications prove that an increased heart rate can be brought on by all kinds of situations. Essentially your body senses something – whether that's excitement or danger or anything else – and attempts to help you deal with it by releasing adrenalin, which speeds up your breathing and heart rate.
That means that although it might be interesting to chart how different things affect your heart rate and watch the graphs move up and down, it could also tell you something meaningful about your behaviour as well as things that you might want to change, address or better manage.
We wanted to see just how interesting heart rate data actually is when it's not tied to a brand or marketing claim, how heart rate is affected by real things in the real world, and whether it gets more interesting than a simple peak and trough.
I offered to take part in a huge range of 'activities', from VR experiences, getting on a ghost train, watching a scary movie, having sex and shoplifting all the way through to the opposite end of the spectrum: being hypnotised, meditating and floating in a sensory deprivation tank. All in the name of investigation, of course.
Collecting a baseline: Average HR 69bpm
I was raring to go with the experiment – while also being terrified and already hideously self-conscious about tracking everything – but I needed to collect a baseline first.
RHR (or Resting Heart Rate) refers to how fast your heart beats per minute (bpm) when you're at complete rest. Generally speaking, the lower the number, the fitter you are. The average adult will have a resting heart rate between 60 to 100 beats per minute, while athletes are likely to have a much lower bpm, somewhere between 40 and 60. I took a reading when I was working, so I might not have been fully at rest, but it averaged at 69bpm, which is fairly average for a moderately fit 29 year-old woman.
Next up I wanted to figure out my limits and find out what my MHR (or Maximum Heart Rate) could potentially be. According to data from the British Heart Foundation, the simplest way to figure it out is take your age from 220. So my maximum is around 191.
From there it's time to work out my target heart rate. Which is the zone the BHF recommends you find yourself in for at least 150 minutes per week for a healthy heart. It's roughly 50–70% of your MHR, so mine is between 95bpm and 133bpm.
Sure this isn't based on the most ground-breaking or solid of science – there are more accurate ways to get more specific. But it did provide a guide as to what boring, normal rest looks like to me.
I'm not going to lie, I also thought it'd be great to prove that a lifestyle filled with sex and scary movies could kinda, maybe, a little bit, make us all healthier and better human beings.
Floatation tank: Min heart rate 40bpm (maybe)
I saw this experiment as a great opportunity to try a floatation tank for the first time. I've read that people have really varied experiences, from some being panicked and losing their shit to others literally having the most blissful experience of their whole lives. Both of which I thought would look freaking awesome on a heart rate graph.
My experience was mixed. There was some existential dread when I came to terms with the fact that I was faking paralysis in pursuit of being a bit more chilled. But there were moments when I did feel euphorically serene, in amongst moments where I actually saw flashing colours and others when I got kinda bored.
It's fascinating to see my heart rate stay in the mid-range of the lowest zone when I expected that it might sink really low. Well, apart from a few occasions where it creepily plummeted to zero. I'm convinced this is when I had hallucinated and briefly crossed over into another dimension (like the Upside Down in Stranger Things), but I don't have much (any) hard data to back that claim up.
I knew the ghost train, scary movie and sex were bound to get my heart racing. But I wanted to really push the experiment to extremes, and I knew very little was going to give me the same sense of absolute panic as shoplifting. I remember once as a kid I accidentally stole a tube of Smarties, took it back in floods of tears and probably developed some kind of shame complex I still carry around in my unconscious to this day.
After mouthing off on Twitter about dreaming up a criminal mastermind plan, I strapped on the Mio Alpha 2 (already feeling TERRIFIED) and did it. I won't go into too many details about what I stole from where (a salted caramel bar from a big high street retailer). But what was interesting here is how even before I began shoplifting my heart rate had reached astronomical levels.
In the same way the Mio Alpha 2 couldn't quite handle my floatation hallucinations, it literally dropped out halfway through 'the heist'. (Or my heart literally stopped beating out of fear of being arrested, you make up your mind.)
My heart rate reached a huge 157bpm, which is way higher than any of the other activities I took part in.
The other fascinating thing here is my heart rate actually stayed worryingly high for HOURS afterwards. It went down to around 130bpm, but as my resting is 69bpm it's no surprise I didn't get much sleep that night. It's also no surprise some people get addicted to the high that comes with your body being in a state of total panic.
Hearts and bones
Hypnosis: Min heart rate 49bpm
I've been hypnotised a few times before and always find the experience to be extremely soothing – which is probably due to the fact I've only ever experienced it in a therapy setting, not being stood on a stage barking like a dog.
For this particular session I asked my hypnotherapist to help me chill the fuck out, basically. Now it's worth mentioning that I'm highly suggestive and have a vivid imagination. So within minutes I felt like I was in the deep depths of my imagination, being covered in glitter and floating through glaciers on a big dog thing NeverEnding Story-style. Which is pretty apparent from the heart rate chart, taking me to a low of around 49bpm.
This magical journey was only slightly spoiled by the fact I sneezed halfway through, which was a shame, but it's also funny to see that spike in the chart.
Sex: Max heart rate 132bpm
I won't delve into the minutiae of the sex chart and what was happening at each point in case I inadvertently make heart-rate porn a new niche fetish. (And because my byline is literally right there for eternity.)
The aim of this sexual experiment wasn't longevity (as if that wasn't obvious) but tracking orgasms and seeing what they did to my heart and whether that correlated with what I felt in my body.
During ten minutes I climaxed twice and I found it fascinating that the second time seemed to immediately send me into a state of euphoria, which may have been when dopamine levels dropped and oxytocin kicked in.
My heart rate reached 132bpm at the peak, which proves sex is just as good as a moderate workout when it comes to heart health. Feel free to use that excuse next time you're considering heading to the gym.
Scary movie: Max heart rate 129bpm
Given heart-rate monitors have been used in movie advertising, I was interested in seeing whether the results would really be as dramatic and volatile as they look in promotional materials.
The scariest thing on at the movies was The Shallows and it was, surprisingly, a really decent thriller. It was also great for me personally because I have a) a bit of a shark fear and b) a bit of a Blake Lively crush, which is apparent from some of the huge spikes in my heart rate that coincided with the biggest jumps and shocks of the movie.
Meditation: Min heart rate 62bpm
I've been meditating for a few years and find it relatively easy to get into a calm, mindful state. So much so that I've probably become one of those smug meditating dickheads.
For this one, I was surprised that my heart rate only slowed a little throughout the ten minutes I was meditating – maybe I shouldn't be so smug about my skills after all? Now this could have been because I was only dedicating ten minutes to it and was also acutely aware I was being recorded by my Mio tracker. Or it could still be a really solid testament to the benefit of meditation as an anxiety-reducing tool – even if the heart rate stats didn't drop as much as I (and my ego) was expecting.
VR Ghost Train: Max heart rate 133bpm
For months there had been so much hype about professional mind messer Derren Brown's latest VR nightmare-inducing ride at Thorpe Park. It was delayed! Fans had travelled from all over the world! Derren dreamed it up in his mind all by himself! There's a long list of restrictions! But although I was impressed by the ambition of the ride itself, I felt a little let down by the overall experience. (Check out my full review here).
Having said that, my heart rate told a different story. During my time on/in the ride, I reached a heart-rate high of 133bpm (only later beaten by the salted caramel incident). And although there were plenty of lulls too, this was likely the desired outcome given Derren Brown's brand is one that creates a false sense of security and then proves to be really, well, creepy.
VR spiders: Max heart rate 130bpm
After trying VR with Derren and his – let's face it – slightly disappointing ghost train, I took the opportunity to see if VR would have the same effect if I used it to confront some of my deepest, darkest fears. I picked a mixture of environments to scare myself silly with, including having tarantulas running over my hands and being in a tiny room that kept getting tinier and tinier like something out of Saw.
As expected, the fact I was experiencing all of this messed up stuff via VR and not real life didn't dampen my heart rate much – although I was too chicken to compare it to actual tarantulas and rapidly contracting rooms to know that for a fact.
The scary environments continued to scare me each time, which was interesting. I'm told that usually treating a phobia with VR takes a few sessions, but as I only had five minutes I was left, quite frankly, terrified.
As you'd expect, the shoplifting, VR ghost train and multiple orgasms made my heart rate soar the highest. These findings are hardy surprising, but to me it was really fascinating to see how my heart rate changed and what kind of state my body was in before and after. Like the massively elevated heart rate after shoplifting and the huge drop-off after such a high heart rate during sex.
Now I'm not condoning shoplifting here, but I do recommend that if you have a heart rate monitor for work outs you keep it strapped on from time to time. You might learn something about what gets you scared – or gets you off – and there's nothing quite as satisfying as looking back at a graph and saying, "that's when I stole the caramel bar", "that's when I came again" or "that's when I literally parted time and fell into another dimension".