Bicycling is probably one of the more popular activities that Apple Watch wearers like to track and I would be included in that crowd.  Fortunate for me, I live close to a great bike path in Central Illinois that winds through forests, meadows, a conservation area, and along creek and river bottoms.  It’s a great place to view wildlife and get away from the city.  It’s also a wonderful workout and so I used it  to test the Apple Watch Series 4, which I’d only received a few days earlier.  The watch performed very well!

The built-GPS and heart rate sensor didn’t seem to miss a beat.  Like I’ve written before in previous articles, the Apple Watch Series 4 built-in GPS is very fast to connect and so far has always remained connected in my tests and this one was a fairly long test.

Battery Life When Using GPS

Battery life for the Series 4 has been a big surprise to me as well.  I was expecting to have to have to worry about charging the watch in the evening but it is easily achieving a day and a half of battery life and that’s using the GPS and calling features.

Before I began the the 1 hour and 25 minute 12.12 mile ride, the watch had 96% of the battery remaining.  Even after taking two phone calls through the watch during the ride and having the GPS running for nearly an hour and a half, the battery only drained to 87% which I think is very good.

If you’re an avid cyclist, the Series 4 is probably going to last for even some of your longer rides, depending upon environmental conditions.

>>View price and availability of the Apple Watch Series 4 @ Walmart

Distance Estimates

The distance estimate of the bike ride by the Apple Watch Series 4 seemed to be right on the money.  Using an online tool to estimate the distance,, the distance estimate was very close between the two. Although this isn’t the most precise way to measure distance, it’s good enough to get a good sense of how well the GPS performs.  The online tool estimated 12.18 miles while the Apple Watch estimated 12.12 miles.

Another way to tell if the GPS did a good job following my route is to take a look at it on the map.

A basic map of the bike ride

A basic map of the bike ride

Satellite view of the bike ride

The satellite view of the bike ride


apple watch series 4 GPS route accuracy

In this view I can that it followed the path very well and even shows that I stopped at an overlook at a pond. The red lines indicate slow speeds or when I stopped.

Where I stopped at the pond

Where I stopped at the pond.

The satellite view of the bike ride

This is the bridge over the Sangamon River in which I stopped to take some photos. The red line before the river shows where I first stopped and the red line going across the bridge shows when I walked the bike across the bridge and stopped to take some more photos. The GPS did an excellent job here.

Where I first stopped at the bridge crossing the river

Where I first stopped at the bridge crossing the river.

Sangamon River

A photo of the Sangamon River, and my finger. I haven’t quite gotten used to the location of the camera lens on an iPhone!

The Apple Watch Series 4 has a great built-in GPS

And here is a very tricky spot for every fitness tracker and GPS watch I’ve tested. Most have a very difficult time tracking me as I cross the bridge and turn the corner to cross the road. The Series 4 did better than any other GPS watch I’ve tested so far.

Below are the stats for the outdoor cycling activity

Activity Duration: 1:25:15
Avg Speed: 8.5 mph
Active Calories: 353
Total Calories: 467
Elevation Gain: 336 ft
Avg Heart Rate: 112 bpm
Distance: 12.12 mi


The Apple Watch Series 4 battery usage has surprised a good way!

The Apple Watch Series 4 battery usage has surprised me…in a good way! This is the 40 mm version. After a 1 hour and 25 minute outdoor cycling activity using GPS, only 9% of the battery was used.  During this time I also took two phones calls through the watch.

Heart Rate Accuracy

I haven’t yet compared the Apple Watch Series 4 to a chest heart rate monitor but form what I can tell looking over the data, the watch seems to be performing very well.

I’m not seeing any erratic behavior from the sensor.  I’ve done enough tests to know how my heart does during activities and can tell when a HR sensor is good or not.

I’m going to say the optical heart rate sensor of the Series 4 is accurate but I’ll be sharing test results for the full review.



What I Would Like To See From the Apple Watch for Cyclist

One things I miss on the Apple Watch is breadcrumbing.  However, there are good third-party cycling apps that can be used on the Apple Watch to show your location on a map.  AllTrails is a good one as well as Endomondo, and several others.

I’m going to be trying several of these third-party options and give my recommendation for the best ones because I’m eager to see myself how well they perform on the Apple Watch, and how well I can see the screen as I ride.

Many of these maps can be shown on your phone’s screen as well as you ride which would be the more practical option for viewing.

It’s obviously not a good idea to take your eyes off the trail or road for long when bicycling but it is helpful to be able to stop and see where you are in relation to your surroundings.

The Apple Watch does have a map app built-in but these third-party options usually have trails and routes that you can follow with navigational prompts.  I’m interested to see if the battery takes a hit from these apps, so much more to come!

Anyway, I had a very enjoyable time on my late September bike ride.  So far, I’m very impressed with the accuracy of the Apple Watch Series 4 for outdoor bicycling.


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Last Update: November 5, 2018