Houston, Texas-based coaching platform BSX Athletics launched a Kickstarter crowdfunding campaign this week for a new fitness tracking wearable, called BSX Insight. The device costs $179, for those who pre-order it through the Kickstarter campaign, and that includes a six month subscription to BSX Athletics' online training service.

While the device tracks heart rate, cadence, and pace, like some other activity trackers on the market, the company claims it also tracks lactic acid buildup. The company says this will be a helpful metric for athletes who want to learn how hard they are working out, compared to how hard they could be working out. The company is selling three different versions of Insight, one for runners that costs $179, one for runners and cyclists that costs $219, and one for teams that can store data for up to 10 athletes that costs $799.

Insight uses an LED light and an optical sensor to check lactic acid levels, according to the company.

"As the light passes through the muscle tissue, it is reshaped by elements within the tissue (known as chromatophors) to produce a unique signal (similar to a fingerprint) that contains information about the local metabolic activity," the company explains on Kickstarter. "This profile is then processed by embedded BSX algorithms to analyze identifiable signal features which exist within the profile. When combined together, these are used to accurately generate a lactate threshold curve."

Athletes attach Insight to a compression sleeve that they wear on their leg. The device connects with the Garmin sportswatch through Bluetooth and ANT+. While they are working out, the device will vibrate to indicate that the athlete should work harder or slow down. At the end of the workout, the information is synced with the BSX Athletics web-based program, TrainBSX so users can review their data.

Eventually the company aims to also integrate with other sports watches including Polar, Suunto, and Timex.

BSX Athletics plans to use money from the Kickstarter to finalize prototype design, prepare for manufacturing, integrate Insight with other watches and training platforms like Training Peaks, Strava, and Daily Mile.

In March 2013, BSX Athletics raised $2.5 million from six private investors to build an iPhone app, runBSX, and continue development on Insight. The app was expected to launch in April 2013 and offer custom training plans from coaches, and while the company promoted it via Twitter as recently as September 2013, it is no longer in the Apple App Store.

In July 2013, researchers at the University of California in San Diego published an article in a medical journal affiliated with the American Chemical Society about a wearable sensor that monitors lactate levels through sweat.