Getting smarter

Advancements in wearable tech mean that deep dive data isn’t just for the professionals

The Sport Tester PE3000 – that probably sounded pretty futuristic back in 1984. And indeed it was, because this wearable device from Polar brought real-time heart rate monitoring to cycling, arguably kicking off the trend for metric-driven training that pervades to this day.

The device was a serious piece of kit. About the size of a matchbox and worn on the wrist, the Sport Tester linked wirelessly to a sensor stuck to the rider’s chest and could link to a portable Canon X-07 printer to run off cardiogram-style printouts.

It’s funny how little has changed between then and now: substitute an optical heart rate sensor on the back of the watch for the strap, and Strava or Trainingpeaks for the dot matrix printer, and modern rider-monitoring setups are basically the same today. However the data that can be harvested isn’t just more advanced, the way it’s processed has come on in leaps and bounds too.

Take Garmin’s latest Fenix 6 watch. Of course it can monitor your heart rate, but it can combine this with monitoring your workouts, daily activity and sleep to give you a stress score, one single number whose magnitude correlates to how stressed you are. And that’s not all. Algorithms then interpret this data as what Garmin calls Body Battery, a percentage ‘score’ that purports to tell you how energised or drained you are. These two metrics can help inform training – should you go easier or harder today? – but if that’s too complex for you to interpret yourself, after every workout the Fenix decrees how many hours’ rest is needed between the workout just gone and the next.

It’s quite incredible stuff that seems to work, and Garmin is not alone. Polar’s latest wearable, the

Vantage V2, features Training Load Pro, a system for assessing cardio load, summarising sessions into categories – ‘detraining’, ‘maintaining’, ‘productive’ and ‘overreaching’ – and giving associated numeric values. Then there’s the Leg Recovery Test, where the Vantage assesses you as you jump to see if your legs are in good shape to cycle or run.

Of course all of these metrics are extrapolated – the Fenix will give a VO2 max reading but because it doesn’t also come with its own oxygen mask this should only ever be considered an estimate. Yet both anecdotally and through independent testing, such numbers would appear fairly congruent with a lab, and at any rate, like a poorly calibrated set of scales, this data at least has meaning within itself.

Plus it’s a hell of a lot cheaper than hiring your own coaching staff.