Neil Featherby: Why you shouldn't completely rely on your GPS watch

Callum Bowen Jones GPS watch

Callum Bowen Jones shows his GPS watch after the British 10K Championships but the official time told a different story - Credit: Callum Bowen Jones

Pace makes for the perfect race is something which I regularly tell those who ask for my advice particularly when it comes to wanting to PB in the longer distance races.   

Whilst all runners want to be proud of their PBs, for those who race regularly and particularly those at the sharp end, going for a personal best cannot always be on the agenda.       

However, with the use of GPS watches these last few years you need to be careful if you rely on them too heavily as one of my athletes, who I coach, Callum Bowen Jones, discovered this week when running in the London Vitality British 10K Championships on Bank Holiday Monday. 

On the morning of the race, I told him to settle in after the first 1km and then be prepared to stay with it and not to keep looking at the watch.  

“If you are hurting and hanging on by 8k, so what everyone else will be hurting too so just give it everything you’ve got to not only PB but also finish as high up in the race field as you possibly can.” 

PB he did (31:17), but his finishing time was well off what he is capable of and expected. 

Cal really is disciplined when it comes to his training and indeed racing so he decided to stick to 3:04km splits which would give him a finishing time of 30:40. He also decided to run to the set pace via his GPS watch. 

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Unfortunately, and whilst his watch suggested he was nearing the finish almost bang on his target time, elation very quickly turned to disappointment after going through what his watch said was 10k (30:42) only to discover that he still had a couple of hundred metres left to run before crossing the finish line. 

Like several others he bemoaned the fact that his watch said 6.34 miles as opposed to 6.21miles. “Did your watch bleep bang on each of the race km markers?” I said.  

“No mine and others were all coming up a bit short, but we just assumed that the race markers weren’t all positioned correctly,” he replied. He also said he felt comfortable running at the set pace for which I further said “then never assume and you should have ran harder.” 

As I pointed out to him, it’s the time you cross the finish line which counts irrespective of what your watch might be suggesting. 

At the end of the day he came 31st in a National Championship race where Sir Mo Farah finished 2nd and apart from the PB, he also won a bronze medal what with his club finishing third in the team race. If Mo, who also belongs to the same club, had worn his club vest, then they would have taken silver medals. 

Nevertheless, and here is perhaps the biggest lesson for Callum to take from it all and that is to now be a bit more confident when racing and run to feel.  

At the same time not to always rely on the watch especially if the km and mile markers are suggesting otherwise. Someone recently said to me, you can’t beat an old-fashioned Casio watch. 

With regards to the accuracy of road racing course measurements, all major races going right back to the 1970s have been measured by using what is known as a Jones Counter attached to a calibrated bicycle. 

Lots of criteria comes with this too which I did actually write about a few years ago in one of my columns (Nov 30th 2018). 

All races which come under AIMS (founded in 1982) and IAAF jurisdiction are likely to be a little over distance what with not only adhering to the most stringent of guidelines set out, but also when following the very shortest possible line when measured. One where it is unlikely that even the very elite at the front can follow all the way. 

I am pretty sure that for every km measured a further 10 metres is also added. This then ensures that any records set can be ratified upon any remeasurement. 

For instance, Alberto Salazar’s world marathon record of 2 hours 8 mins and 13 secs set at the New York Marathon in 1981 was later found to be 170 yards short when remeasured despite the New York Road Runners Club insisting that the course was accurately measured. 

Therefore, when runners (particularly after having ran in a major marathon) say that their watches indicate that they have ran further than 26.2 miles, the likelihood is that they have.  But most importantly every athlete from the first to the last can be sure that they have ran at least the full distance. 

For those who don’t already know, here in Norfolk Richard Thornhill is a credited course measurer. However, I always like to mention an old friend who sadly is no longer with us, Roger Gibbons. He told me that if needs be he would measure across people's gardens if he thought there was an opportunity for runners to take a bit of short cut.    

Whilst GPS watches are very accurate, there are times when they can malfunction be it through the weather, high sided buildings and far too many twists and turns. 

One person who I doubt relies too heavily on a GPS watch when it comes to racing is Colchester Harriers Adrian Mussett who at 50 years of age once again won the GEAR 10K in King’s Lynn also on Bank Holiday Monday in 32:06. 

Adrian is an amazing athlete and has been winning races in the county going right back to the 1990s. He really is a true inspiration when it comes to having a great mindset and real desire to keep pushing himself despite his advancing years. I must also mention 40-year-old Bure Valley Harriers Michael Eccles who took the runners up spot just eight seconds behind Adrian. 

Lastly for this week – well done to Norfolk Trail Runners, Colin Weller who completed the Thames Ring 250 Mile Trail Race… yes 250 miles! Absolutely mind blowing. He finished in a time of 81 hours, 11 mins, and 35 secs.