Apple Watch with cycling power estimation is a step closer to reality

Back in 2017 US tech giant Apple filed a patent for calculating wind resistance for cyclists using their smartwatch. The patent has just been granted, moving Apple one step closer to power data on the Apple Watch.

In the patent, Apple says that the watch would calculate an estimate of wind resistance via the watch’s orientation, velocity, altitude and where it thinks the hands are placed on the bars. Heart rate data from the built-in optical sensor would also contribute towards providing an estimate of the rider’s power output.

The estimated power numbers would be heavily reliant on a number of other estimated factors like friction generated by tyre pressure, surface type, wind direction and speed, suggesting to us, that like the Arofly valve cap power meter, accuracy might not be a strong point.

Mat took a look at the patent when it was applied for back in 2017 but if you’ve forgotten the detail, we’ll briefly refresh your memory.

“The wearable device can include a heart rate sensor to provide a series of measurements of cyclist heart rate. The wearable device can also include motion sensors to collect data about the wearable device's position and orientation in space and to track changes to the wearable device's position and orientation over time. 

“Accelerometers in the device may track acceleration, including high-frequency variation in acceleration, and use this to detect surface type. Because a cyclist can wear the wearable device, the orientation of the device can provide information about the cyclist's body position. 

“For example, when cycling, the cyclist's arms may be in a variety of positions, depending on the cyclist's style of riding and the type of handlebars on the bicycle. If the cyclist wears the wearable device on the cyclist's wrist, the wearable device may be able to infer the cyclist's hand position, and based on this hand position may be able to infer the cyclist's riding position and thereby provide an estimate of drag contributed by the cyclist's body.”

“Combining these measurements of heart rate, position and orientation, velocity, altitude, and riding position, the cyclist's total power output and the contribution of each component of that power output may be estimated. By estimating the relative contribution of each component to total power output, a less expensive and more power-efficient technique for providing accurate estimates of cyclist power output can be created.”

It didn’t sound that accurate in 2017 and we’re still not convinced, but what the patent being granted means is that we are a step closer to seeing a finished product.

But should we actually end up seeing power data on the Apple Watch then it may be good enough for the majority of Apple Watch users who may just see it as a fun data point when they go for an occasional cycle.