Ballet & Tech (A First Attempt)

Me (on and off for the last couple of years): “It would be awesome to have a power meter or something so I can go all data on my training…”

Twitter:

Has any dancer ever measured a performance with a fitbit or pedometer? How many steps? How far do they dance? PLEASE will someone do this?

Me (in Jo Siska’s ballet class on Wednesday): “OMG Jo! Look! Data!”

Inaccurate data. But that’s what this is, a test of how to get meaningful and accurate(-ish) data on what goes on when I’m dancing.

When I was living in Wedding, part of my training routine was morning cyclocross rides in the forest around Flughafen Tegel. Last year when I inherited an (old, 4s) iPhone and stuck Trails app on it, I started to see what the intangible feeling of each ride represented. A couple of things were missing though, one of which I finally prodded myself to buy this week – a Polar H7 heart rate sensor (yeah, I got the pink strap). The other is one of those crazy expenses I’m unlikely to throw euros at unless I have around four thousand of them spare for a new bike: a power meter.

Power meters tend to be the province of bike crank arms, pedals, or hubs and cost about double what normal people spend on a whole bike. And none of them are objects you can take into a dance studio. Slightly getting there is the rpm2 shoe insert power meter, still no good for dance though. Which leaves the very new Stryd – and very cheap, not much more than a Fitbit (which I’ll get to later), and about the same size as the H7 – a power meter for runners.

Before all that, Wednesday. In the studio with my heart sensor on and my iPhone beside the barre, cos it uses Bluetooth to sync. That’s several problems right there. First, doing ballet (or generally dance) training with an iPhone lodged somewhere is not so practical, which means a pedometer is going to count exactly zero steps. Second, Bluetooth is possessive, it likes quasi-line-of-sight and proximity. Bouncing around ten meters down the studio with heart monitor facing away from it is going to generate some highly improvised heart rate info. If, for the sake of science, I slip my iPhone into my trackie pocket, I’ll get pedometer info, but any GPS-based data capture (speed, distance, location) is comically useless, having an accuracy of greater than 4 meters. I was dumping my heart info into Trails, which is a fine app for cycling training, and much of the time it had my location not even in the same building, plus my altitude changed by 24 metres.

Thursday on my morning training ride around Tempelhoferfeld, I used both Trails and Polar’s Polar Beat. The data resolution of both is pretty good, Polar Beat is more fine-grained, and neither had a problem with my phone being in the back pocket of my jersey. I’ve been doing enough cycling with data recording to know what looks right.

Which leads me to Fitbit, cos my flatmate has one. It stores the data locally so no need for a live Bluetooth connection. It does heart rate, pedometer, a bunch of other useful garbage, makes pretty data, syncs to phone, laptop, or to fitbit.com, and looks like a dainty watch strap.

So, Friday, ballet again. This time with a Fitbit and my H7 going to Polar Beat.

I’m siding with Fitbit when they say their data accuracy decreases outside fairly limited activities: both heart monitor and step counter are dependant on arms not windmilling for acquisition of useful data. Perhaps it requires repeated use to find the best spot on my wrist, but compared to the H7, Fitbit reported my average heart rate at ~20bpm less – I stuck fingers to neck and what the H7 shows is a good match. As for steps – and ignoring the first 18 minutes or so where I have no idea who it thought I was – it gave around 250 for the entire 40 minutes of barre, and 2200 for the class; obviously not counting a pas de bourée as three steps.

The H7 doesn’t do step counting – unless you pair it with their walnut-sized Stride Sensor somehow affixed to your foot. Its heart data though is magical. You can see every exercise through the class mirrored in my increased heart rate, and check out the centre adage starting at 40 minutes, where the curve is almost identical for both times, and the arc through the entire class, building intensity in small stages at the barre until peaking through the centre into longer and longer periods of maximum effort, before révérance-ing out. I can also look at sections, so if I select just the centre, then my average heart rate goes up to 167 and only once drops below 120. Lots of good data you can do stuff with. (And I can even assign training to Ballet, with a fancy Olympic-looking arabesque!)

But what about power? Or other stuff? Stryd for the power (and heart rate), and RunScribe for everything else? Would they even handle dancing? RunScribe would be awesome for visualising the mechanics of dancing, g-force, velocity, ground contact time, pronation – if it could handle the foot chaos. And then what to do with all this information? If it’s all just for a bit of woohoo! then Fitbit and its social network gamification of sleeping is fine. But if it’s for the purpose of improving performance, technique, being more diligent in how you train, that’s a whole other thing.

Ballet training with Polar H7 Heart Rate Sensor
Ballet training with Polar H7 Heart Rate Sensor
Ballet training with Fitbit Charge HR
Ballet training with Fitbit Charge HR