There are many reasons why I love running, but most of all it's because of its simplicity. Throw on a T-shirt and some shorts, lace up your shoes and your workout starts once you're out the door. It's not logistically challenging, unlike swimming or cycling, which I also do as a triathlete. My runs used to be based on feel. My legs and feet would set the pace and distance. If I was tired I would turn for home; on many occasions euphoria carried me farther than expected. How far or how fast I would go was unknown and arbitrary, the only thing that mattered was that I had been for a run. Running is a primal act, and I liked keeping it that way, even shunning portable music players to have only my breath as a soundtrack. But a couple of years ago this all changed when I got a Garmin Forerunner 405CX, a GPS-enabled running watch, as a birthday present. To call it a watch is an understatement - it's more like a mini-computer, and certainly felt like a brick on my previously bare wrist. Like a ball and chain, the watch now holds me prisoner. Firstly, I have to remember to charge it - the battery barely lasts a good long run of about four to five hours. (Since May, when a friend from Prague left his GPS watch behind, I have owned the Garmin 310XT, with a battery life of 20 hours.) Then there's the frustrating wait for the watch to locate satellites. Outside my Causeway Bay apartment, overshadowed by towers, it's difficult to give the gadget the clear view it needs to latch onto satellites. It can take 30 seconds, but rarely; at times I've waited 15 minutes. When the watch is finally ready and the run begins, so does the obsessive-compulsive need to keep checking it for pace, distance covered, current elevation and elevation gained. (There used to be heart rate too, but the chest strap suffocated me so I ditched it. And there's also a calorie count, but I'm not bothered.) If you find plodding along lonely, there's an option for you to pace - or compete with - a virtual partner, which shows up as a running stick man on the watch. In a lot of ways, running with a GPS watch is no different from those tech addicts you see constantly checking their iPhones while walking down the street. Annoying. Satellite signals and tracking can be iffy, especially among tall buildings or within a thickly forested trail. On a pancake-flat running track, the watch once claimed I'd gained a couple of hundred metres of elevation. Nevertheless, according to Bruce Pye, managing director of Sports World, an official distributor of Garmin products in Hong Kong, the city has gone from being the smallest market for Garmin watches in Asia two years ago to the second-largest, just behind Japan. 'Our aim is to be the largest market in Asia by the middle of next year,' Pye says. Polar, Suunto and Timex are also popular makes, and the Nike+ SportWatch GPS debuted recently. Arthur Tjandra, a cosmetic surgeon who runs for fitness, says that despite the frustrations (similar to my earlier rants), 'I love my GPS, as I can keep track of my training.' Roy Foo, a recreational runner, agrees: 'I'm a techie and I thrive on seeing the detailed stats on Garmin Connect, which spurs me to find new ways to train and run faster.' Likewise, this is where my adoration of the GPS watch comes in. The Garmin synchronises wirelessly to my laptop in seconds, then transfers all the data to the Garmin Connect website, which displays all the beautiful post-run statistics. There's a map of the route run, graphs showing my speed against distance and the course profile, lap times and pace, and a whole lot of other performance metrics short of medals won. It also acts as a log of my progress as I train towards that big race. 'The market [for GPS watches] is huge, as anyone who is doing any kind of exercise wants to know how they're performing,' Pye says. 'Think of the Garmin watch as a training buddy, motivator and coach, giving you vital information and helping you work out at optimal levels.' It's becoming so ubiquitous that my friend Sandro says at the starting line of last year's Ultra-Trail du Mont-Blanc, a 166-kilometre race through the Alps, his watch started to pick up everyone else's heartbeat, and then indicated he was moving at 560km/h. 'I didn't have time to reset it before the race started, so I just switched it off - not great,' he says. 'It's a real love-hate relationship.'