A future iPhone could see if you're not working out hard enough

An iPhone camera pointed at your face could detect effort and strain, or the total absence of it. Here's how future iPhones will mean not being able to trick Apple's activity ring.

At first it sounds as if Apple will look to see if your cheeks are getting flabbier, but rather than assessing the calorific intake of those burgers you're having, the plan is to figure out when you're using up those calories in exercise.

A newly-revealed patent application called "Tracking Caloric Expenditure Using A Camera," is based at heart on how much effort you're putting into exercise.

The idea is that the iPhone obtains "face tracking data" in order to help with determining steps, speed, and stride length. Together with motion sensors, it could determine the gradient of a surface being run on, and ultimately calculate "a caloric expenditure model."

There are already devices that will estimate caloric expenditure, using motion sensors, heart rate sensors and so on. However, these "fitness applications require that the tracking device be worn on the body of the user, which is typically the wrist, chest, torso or foot."

Apple is seemingly not keen on wearable fitness trackers, despite its Apple Watch being one of the best of them. This proposal would rather see calculations taken by face-scanning, and for the scanner to be on a treadmill.

Detail from the patent applicatin showing how a treadmill could include fitness cameras

"[A] face tracker of a tracking device (e.g., face tracking software of a smartphone) receives video frames captured by a front-facing camera of the tracking device, such as a smartphone," continues the patent application. "The tracking device can be, for example, a smartphone resting on a tread mill console while a user is exercising on a treadmill."

"The face tracker uses various coordinate transformations to track the motion of one or more features of the user's face," says Apple. While the patent application stresses other software can be used — and even lists examples — its examples use Apple's ARKit, the augmented reality framework released first in 2017.

At around the same time, Apple also launched GymKit, which sees iPhones integrating directly into fitness devices such as treadmills. This new patent application appears to presume that GymKit is not available, because otherwise a treadmill could already transmit data about speed and gradients.

But then Apple notes that the proposals |are not limited to treadmill workouts, but can be used with any exercise or exercise equipment where camera tracking data provides an indication of a fitness metric, including but not limited to tracking other parts of the human body."

"For example, the disclosed embodiments are applicable to any exercise, health monitoring application or fitness machine where vertical or lateral face motion can be captured by a camera, including but not limited to counting squats, pull-ups or jump rope steps," it continues, "where there is vertical motion of the face, or lateral motion of the face, such as side step exercises."

Apple doesn't want to be Peloton

Patent applications are long on detail but minute on the benefits, they are great for how rather than why. In this case, though, the patent application's many drawings of treadmills hint that Apple wants to enter Peloton's market, but the text suggests not.

It's definitely aimed more at future iPhones being used with any manufacturer's treadmills, than it is about an Apple-made exercise device. Otherwise there would be no reason to use face scanning to estimate workout effort, because the Apple treadmill would be constantly reporting how fast its user is going.

Using the strain on your face to calculate calorific expenditure is clever, and the three credited inventors propose some smart ideas. But it's a shame that the cameras can't pick up that you've been to Applebee's and so must atone with five laps at the gym.

For the current closest to that ideal, you'll need to use an app such as MyFitnessPal. That also can't automatically determine the value of a pizza, but it can prompt you to be honest about your calorie intake.