Running Watch Advice Please

[Lynda68]

I regularly run laps in a small space. My TomTom running watch needs replacing after seven years. I would be grateful for any advice on a watch that would record the correct distances in a small space. My TomTom accurately recorded the time but the distance showed as roughly half.

[UnfitNoMore Graduate]

I love the Garmin (forerunner) range and there’s something for every budget. As for small spaces, they can be tricky… a deep dive into settings will let you change the GPS sampling rate from its default to every second, at the expense of battery life. Most new watches also allow you to run with more than one positioning system at a time, some even let you use 3 at once.. again at the expense of battery life. Watches tend to use the second system to assist the GPS positioning rather than as a separate system.

According to Garmin (other watches will be the same) more accurate measurement happens if you wait a few minutes after the GPS lock before pressing start. I tend to lock onto GPS as I start my warmup walk, so this recommendation is my default.

Also, it’s worth noting that there are watches without their own GPS if you run with your phone, and according to testing I have seen, and also Garmin themselves, the latest (apple) phones are always more accurate than the latest watches, because they use the mobile network to position as well as GPS (assisted GPS). I’m not aware of a GPS watch that allows you to choose to use the phone instead… though I could be wearing one 🤣 I don’t take my phone running often, so I have never looked.

Hope this helps.

[nowster Graduate in reply to UnfitNoMore]

If you sync with the Garmin app up to an hour before setting out, it will update the watch's GPS data so that it locks on more quickly at the start.

In general, the newer running-specific Garmin watches (eg. Forerunner 45 and 55) have better GPS chips than older models.

And I'd steer away from a running watch with a touch screen. They're easily triggered by accident and are a swine to work with gloves on or if you're dripping sweat on them (or it's raining).

[UnfitNoMore Graduate in reply to nowster]

Some of them do the speed lock thing… not all… I need an upgrade!!

[Lynda68 Graduate in reply to UnfitNoMore]

Thanks, you’ve given me a few things to think about. I like the look of the Garmin watches, but may consider the phone option. Thank you for taking the trouble to reply.

[Runningphobe Graduate in reply to Lynda68]

I used to run with a phone app, but was very disappointed when running in a poor reception area and couldn't log the run at all. After that I bought a Garmin watch and have been very happy with it. After several years it stopped working and now I have a Garmin 35 which is also excellent.

[John_W Graduate Ambassador]

Are you saying the TomTom distance accuracy has got worse?

[Lynda68 Graduate in reply to John_W]

Hello John, no it’s never been any good. My reason for thinking it needs replacing is that I have started outrunning the battery within an hour. Having read the advice I’ve received, it may be that I need to have a proper look at the settings and see if I can improve anything. I am grateful for any tips thanks.

[John_W Graduate Ambassador in reply to Lynda68]

And how do you know the distance measured is inaccurate?

[Lynda68 Graduate in reply to John_W]

When I run on the road, my pace is between 6 and 7 minutes per kilometre so I would expect the distance covered in an hour to be more than 8 kilometres when it is showing 4.

[John_W Graduate Ambassador in reply to Lynda68]

Ok, and what are the dimensions of this space that you run around?

[Lynda68 Graduate in reply to John_W]

It takes me about 30 seconds to do one lap.

[John_W Graduate Ambassador in reply to Lynda68]

So not very big at all.

I suggest 2 things:

(1) try the suggestion above to see if there's a more rapid GPS data collection option on your watch.

(2) If you can, borrow a newish Garmin from someone and see how it goes re: distance.

With the space being very small, you'll be struggling to measure the distance accurately with ANY device - GPS only locates you to an accuracy of about 10 metres. You could spend £600 on a nice shiny new Garmin, Polar , Suunto, or Coros and still have the same problem.

Remember also, that in such a small space, your are turning corners many more times than you would on a normal road run . Each time you turn a corner you are slowing down and you're doing that 3 times each lap by the looks of it, meaning that your average pace WILL be quite a bit slower compared to a straightish road run.

By the looks of the screenshot from your app, I'd say that your TomTom was done a pretty good job at locating you , i.e. it's not a crazy looking jig-jag pattern, and therefore the distance (and so pace) might actually be more accurate than you first thought.

Take a look at this from a run around a smallish terrace that I was doing in Spain during the 1st lockdown - the space wasn't big enough nor the GPS accurate enough, for the distance/pace to measured with any confidence:

strava.com/activities/32495...

cc: UnfitNoMore nowster

[nowster Graduate in reply to John_W]

Actually, standard GPS (NavStar) has an accuracy of about 3 metres under ideal conditions. (About 10 feet.)

If you were to put a GPS receiver on a tripod and leave it fixed in one position for an hour, you'd notice that instead of a dot on a map, the trace will have wandered randomly around the actual location, sometimes quite a distance from it.

Lots of things can affect accuracy: walls close by, trees, clouds, atmospheric propagation effects. The latter is why some days your GPS can seem super accurate, and others it's all over the shop.

Galileo is supposed to get an accuracy increase of a factor of ten (about 10-30cm), but that's possibly not in consumer devices just yet.

Some mobile phone GPS chips can aggregate signals from multiple satellite systems: GPS NavStar, Glonass, Galileo, Beidu, but that requires extra computing power, something that is at a premium on a small wrist-worn device.

That GPS works at all is a marvel. Each system has about thirty satellites up there in slightly different orbits, such that most places on earth have at least four of them above the horizon at once. They all broadcast super-accurate time plus some information about themselves and the other satellites in the group.

They all broadcast on the same frequency, and the signal power broadcast is about 100W.

Most of the hard work is done in the receiver. The signals from the satellites arrive at slightly different times (because they're at different distances from the receiver). The differences in times can be used to work out how far away each satellite is, and from their known positions (which is part of the information that's broadcast) the receiver can work out its own location.

Both general and special relativity have effects on the timing too, which the receiver has to compensate for.

And all this is done in a tiny chip that costs only a few quid (in bulk) and can be powered for a few hours off a watch's battery.

[John_W Graduate Ambassador in reply to nowster]

I am aware of the wonders of GPS and try to remind folks that their devices are pinging and being pinged by a small box approximately 36,000 miles in geostationary orbit (ca. 3600 times further away than the International Space Station).

[nowster Graduate in reply to John_W]

The communication is one way. The watch doesn't respond. That would need an impossible amount of power on your wrist.

There are base stations which also triangulate the position of the satellites and tell them where they are (and what ephemera to broadcast).

The satellites are in medium earth orbit (about 12,540 miles altitude).

[John_W Graduate Ambassador in reply to nowster]

Excellent knowledge as always. Now, about the OP ....

[nowster Graduate in reply to John_W]

I already replied! Newer models tend to have better GPS chips. The Garmin Forerunner 45 and later seem to have better accuracy than their earlier models.

You can get better, but you're then into spending £500 or more on a watch. There's no way I could justify (even to myself) buying the likes of a Fenix or similar.

[Lynda68 Graduate in reply to nowster]

Thanks for all your help.

[Lynda68 Graduate in reply to John_W]

Thank you for the information, I will consider all the options.

[John_W Graduate Ambassador in reply to Lynda68]

You're very welcome. I'm curious to know how you get on, so please post again.

[JeanneMary Graduate]

Also consider Hwawei Honor Magic Watch 2 - I love mine which I found because of a recommendation from this group.

[Hidden]

I have a garmin for my bike - but it makes me slightly crazy sometimes - randomly not pairing to Strava, losing my gps info ect. And I have an expensive one. That said- I use my Apple Watch and it works everytime everywhere and if I actually fell down on a run badly, it would know and hopefully do something about it. I know it’s not cheap but it does a lot of other stuff so I don’t feel like I need anything else. I’m a less devices the better kind of person. I’m sure everyone has their own solution so this is just mine

[acemcgraw]

I'm going to put another vote in for Garmin. I've got a Vivoactive 4 that I got for my birthday a few years ago and I love it. Seems to offer so much more than the equivalent priced Fitbit. My wife has a Fitbit, and she's had to replace hers about 4 times in the last couple of years - all under warranty, but the same issue keeps happening and she can't link phone to watch. Whether that's an apple thing or not (she has an iphone) I don't know, but the Garmin has been continuously good, and the Garmin app is really good for tracking exercise and food intake (via MyFitnessPal)

[Wawacito Graduate]

After reading up on the suggestions here in the forum I got myself a Garmin Forerunner 45 S (S = smaller wristband) in December and I have not regretted this decision.

It is easy to use. I like it that is has buttons and not a touchscreen face. I can read it without having to put on glasses (🙈) and do not use half of the functions it has to offer.

All in all great value.

[Week7 Graduate in reply to Wawacito]

Me too!