If you’re looking for a versatile, multi-purpose GPS smart watch that will help you boost your training, navigate your rides and more, then the Garmin Fenix 7 Sapphire is up there with the best mountain bike GPS computers.

Back in the 90s training to ride your mountain bike was anathema. Drinking beer, staying up all night and smoking fags was far more popular, and that was just in the pro ranks.

Today attitudes to fitness, strength and practice have undergone a revolution, it’s now normal for riders of every level to put a few hours in off the bike, and the most basic tool for cardiovascular training is a heart rate monitor.

The Garmin Fenix 7 is a multisport GPS watch that will help you do this, but it’s not basic by any stretch of the imagination. It can record and analyse huge amounts of data about you and use that to tell you when to train, how hard and for how long, how much to sleep, the recovery you need, and even how to relax and focus when you’re stressed.

To do this it’ll measure your heart rate, heart rate variability, breathing rate, blood oxygen levels, sleep (REM, deep and light) and plenty more, packaging it up into neat little graphs and pithy explanations to help you train.

Garmin has made some improvements to the Fenix 7 to make it much more user friendly than past versions. The screen is bigger and clearer and for the first time touchscreen, but most importantly you can now change almost all the settings and navigate around the watch from your phone, and really that hugely improves usability.

The Fenix 7 runs a series of widgets, or apps, so you just need to choose the sport you’re doing that day. Press play on your chosen sport and it’ll record the activity and display useful information like total ascent, speed, distance, lap time, and so on ad nauseum – you can customise it to display pretty much anything you want. Then it packages up the data and presents it to your phone, where you can view your route and all kinds of insights about the activity and how your body coped with it all.

The most important are estimates of your Vo2 Max, training load to tell you whether you have a shortfall or you’re overextending, and the recovery time indicator.

The latter worked well and generally predicted accurately when it would be optimal for another ride, and times when I ignored it would see me over-tired afterwards. The watch also spotted that I needed more low-intensity aerobic exercise to boost my fitness, and would have planned out a training session to cover that (if I’d let it).

Less useful is the Stamina widget (there are endless widgets by the way, but you can also download third-party apps like Kamoot and Strava). It’ll tell you how much juice you’ve got left in your tank, how much time you can pedal at that effort, or how far you can go at your current work rate.

Sounds great, but I took my Stamina right down to 0% after a long ride, then went out and rode for another two hours. Yes I was in bits by the end of that, and it certainly meant I was Overreaching, in the parlance of the watch, but it wasn’t accurate.

A sports watch costing this much also needs to work as a map and route finder, and the Fenix 7 is very well equipped here. You can scroll around colourful TopoActive European maps complete with contour lines on the new touchscreen, and they’re pre-installed on the watch. You can download the rest of the world for free.

It’s also the first watch from Garmin to use all available satellites and multiband frequency sat nav, rather than just GPS, and as such it’s touted as being far more accurate. 

Honestly though, I don’t think it’s any better than it used to be. I can see from comparing routes on the Garmin Connect phone app that it is precise even under thick tree cover, but it can still be 5m or so off course at any time, which is exactly what I found on the old Fenix 6.

The turn by turn guidance works well enough to let you forgo staring at the map as you ride, and I followed some convoluted routes devised to try and trip the Fenix 7 up, but it didn’t put a foot wrong. Where it falls down is that Garmin’s map editor via the Garmin Connect app or website is still as hopeless as ever and editing a course is like a lesson in patience. It’s still much easier to put together a route on an alternative app and upload it to your Garmin Connect account.

The Fenix 7 comes in dozens of different iterations including this Saphire Solar edition, which means it takes some energy from the sun. Underneath the glass is a 100% photovoltaic strip that runs the circumference of the watch face, while the entire screen also has 7% photovoltaic efficiency.

All told the increased size means the Fenix 7 is 45% more effective than its predecessor, Garmin says. In practice this does seem to have a reasonable effect in the right conditions, this summer I nearly doubled the battery life of the watch compared with winter conditions, and sometimes went two weeks between charges. Still, the non-solar version costs £180 less so is arguably the better buy for UK riding.

• Best GPS computers for mountain biking
• Best jackets for riding in winter
• Seven performance metrics every mountain biker should strive for