Garmin Fenix 5 Plus (Sapphire edition)
€820

It’s relatively easy to test fitness trackers. You strap the watch on, go for a run or a cycle (or a walk if you’re feeling really relaxed) and see how it fares. But the Garmin Fenix 5 Plus bills itself as a rugged multisport watch, aimed at serious sports enthusiasts. Trail runners, triathlons, cross country skiing – it’s all there.

So the watch needed something a little more taxing than a gentle jog to really push it. That’s how I found myself standing in the grounds of Kilruddery House in Bray a couple of weeks ago, looking at an obstacle course winding its way in the distance that I was expected to haul myself through for 7km, with no hope of a last-minute forfeit.

Mud, water, electric shocks – what else would you be doing on a Sunday morning? Hell & Back is the kind of thing that the Fenix 5 Plus was built for. The watch itself is reassuringly chunky, with a rugged strap that – thankfully – stays closed. Losing this accidentally in the middle of a mud bath is unlikely. No touch screen here, which makes sense, but that didn’t mean I wasn’t poking at it once in a while. Instead, you have five buttons around the side of the watch case: on the left side, up and down buttons plus the light; on the right, select and back buttons.

It has a rake of sensors, from a heart rate monitor and compass to altimeter, gyroscope, accelerometer and thermometer. It supports GPS, including the Galileo satellite network. So you’ll know exactly where you are, how high you are and where you are supposed to go next. You can even pick destinations from the on-watch maps and have it direct to your destination, turn by turn.

That wasn’t much use to me on this occasion, but if I was out for a run in a strange city, it would certainly come in handy. As would the compass, if I was the type of person who found hiking on a Sunday a relaxing pursuit (I think we’ve established that I’m not, but the option is there). This watch is for serious sports enthusiasts.

The heart rate monitor was both a good and a bad thing. That spike at around 8.45am was when we caught sight of the first obstacle – the ice bath – and realised it was mostly ice cubes. Up to 91 beats per minutes from a resting heart rate of 83 bpm, which was probably already high because I’d spent most of the morning in a state of panic after realising what I’d got myself into. I’m afraid of heights, and I’m not great with water – two things that Hell & Back seems to love.

The Fenix 5 plus may not be an actual medical device, but it certainly saved me on more than one occasion at Hell & Back. Without it, I wouldn’t have known that we had been plodding around for two hours and five miles. I might have been tempted to give up and have a little sit-down. Because while it’s great fun, it’s also hard work. There is a moment when you are crawling through yet another muddy tunnel, emerging into a puddle of mud that you have to wonder, what was I thinking? (The answer: you weren’t. Not really.)

The GPS tracking of my route can pinpoint the moment I got stuck in mud up to my thighs and had to be helped out. As I was being hauled out of the swamp, the man who helped me seemed incredulous that I was wearing a watch. And impressed it had survived so far.

By the last obstacle – a climb up and a slightly wet slide down the other side – the Fenix 5 was grubby, but unscratched. There wasn’t even a mark on the watch face. Which is more than could be said for me.

The good This watch is tough. Tougher than me. It withstood the mud, the water, getting crammed into small spaces and being attached to an eejit climbing through electric shocks. The buttons take a few tries to get used to, but having them there is preferable to a touch screen under those conditions.

It connects to your smartphone, too, for notifications from your apps, and also shows your diary events. You can also put your music on there, with 16GB of space to load tracks on, and now it supports Spotify.

The not so good If you have smaller wrists, it's a little on the bulky side. Plus it's expensive, so you need to really be into your sports to get proper use out of it.

The rest It measures stress levels too. Which, interestingly, peaked at 9.01am for me on Sunday morning. What the watch didn't record: the number of times I deeply regretted my choices (367); the number of bruises I picked up along the route (too numerous to mention); the number of times I took a deep breath, closed my eyes and forced myself up and over another cargo net (four); the number of times I got stuck in the mud (twice); the number of times I fell on my face with no one watching (once).

The verdict A little pricey but the ideal tracker for sports enthusiasts.