The jump science behind Under Armour's smart running shoes

Under Armour's first pair of smart running shoes kept things simple in terms of what you could track from your feet. It recorded time, distance, pace, split times and that was your lot. Now UA is back with three more sensor-packed shoes and the promise that they can now tell you when you're fit to run.

The beauty of UA's running shoes is that they look just like normal running shoes and that's because the sensors are embedded inside. The UA SpeedForm Gemini 3 RE ($160), Velociti RE ($140) and Europa RE ($160) are a little more eye-catching than the UA SpeedForm Gemini 2, thanks to a welcome splash of colour around the heel on the side of the soles. They feel a little lighter too with a more cushioned design offering a more snug fit.

On the data tracking side, it'll still automatically recognise when you've started to run. Alongside the metrics we've already mentioned, it's finally adding cadence but the feature we were most intrigued to find more out about was the new Jump Test, which aims to measure muscular fatigue.

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I wasn't able to try the test out with the shoes, but I was able to try out a demo that simulates how the test works, what data it will deliver and how runners can make use of the information. After logging into the UA Record app, I stepped in front of a big screen, placed my hands on my hips and had to perform six jumps in quick succession ensuring I made a kind of squat-like motion. The idea is that with the shoes on, you'll perform the test before you're thinking about going out for a run.

The chip embedded inside the shoes wants to know your flight time with sensors that sit inside the sole of the shoe. It takes the six jumps but doesn't count the first or the last one. It takes an average of the jumps in between to give you a jump score. That allows UA to predict your fatigue over time. If you spend between 300-400 milliseconds off the ground (like I did), that suggests you might be under a little bit of fatigue and you'll get recommendations based on that.

If you score 400-500, this means you're good to go and you should stay on track with your training. More than 500 means your recovery is great, you've had a good sleep, your nutrition is good and the app might suggest you increase the intensity of the running session or even suggest running further.

It's this kind of smart functionality that I was expecting to see from Under Armour's first connected running shoe. Something that pushes the boundaries and goes beyond the data footpod sensors have already been giving us for a few years now. There's really only one other company that's doing something similar to UA right now and that's Iofit with its smart golf/gym shoe that uses embedded pressure sensors to measure force in different areas of the foot.

The idea that you can get a better idea of whether you're in good enough shape for putting in a big run is something I think all runners can appreciate. It's pleasing to see that Under Armour is sticking to its promise to make data more actionable and this is a great example of that. I'm definitely looking forward to giving it a try for real and seeing if it really can make a difference.