Muscle fatigue is always of interest to athletes and I know I’ve been curious lately working out at the gym. Some days I know I’ve overworked some of my leg muscles because they will be shaking as I’m going down the steps. The thing is, what is that tipping point—the place where a muscle is fully engaged without risking injury? Roger Ribas and his team at King’s College London have been doing some research on that very subject, according to MIT Technology Review. They’ve created leggings with stitched electrodes to examine muscle use during workouts. Of course conductive thread doesn’t stretch, so a zig-zag stitch was used to be sure the circuit could flex without breaking. The advantage of this stitched circuit is that it correctly positions the electrodes over the proper muscles. It also allows for testing out of the lab since the data can be collected and relayed using an Arduino microcontroller. Usually muscle testing has to be done with wires or electrodes that are tethered, making real world comparisons for athletes difficult. Runners will tell you that terrain makes a big difference, and in fact, testers for the leggings were asked to run 5k routes on different surfaces with predictable results.

The data clearly shows how the runner’s leg muscles begin to work harder, tire quickly after a minute or two and then get their second wind before tiring again. However, this tiring occurs quickly on sand, less quickly on asphalt, and least quickly on an athletics track.

I say the results were predictable because if you’ve ever tried running on a beach, you know for sure you are going to fatigue quickly. However, what is interesting is seeing the timing between the second wind. For athletes, this is going to have a profound effect on training, as well as Running Related Injuries (RRI). Other uses include prosthetic, robots and anything else that moves on different environments. If you want more details for this project check out the white paper at Cornell University Library. I know you are thinking this is just for sports medicine fanatics, but would you believe a newer item in our shop is actually a muscle sensor? Check out our MyoWare learning guide that will get you started with all you need to know about muscle sensing. It need not be limited to sports either, think of artistic uses like triggering music or even using it to send text messages using your eyebrows. It’s weird science, people!!

Every Wednesday is Wearable Wednesday here at Adafruit! We’re bringing you the blinkiest, most fashionable, innovative, and useful wearables from around the web and in our own original projects featuring our wearable Arduino-compatible platform, FLORA. Be sure to post up your wearables projects in the forums or send us a link and you might be featured here on Wearable Wednesday!