Exclusive: PulseTracer gives heart monitoring without the chest strap

What's the worst thing about getting fit? Apart from the early mornings, the strained muscles, the sprained joints and being laughed at by youths (iro

What's the worst thing about getting fit? Apart from the early mornings, the strained muscles, the sprained joints and being laughed at by youths (ironically, most of whom are clad in sportswear). Apart from all those things, it has to be putting on a heart-monitoring chest strap to track your progress.

Now a US start-up is about to start beta-testing a heart-monitor watch that can track your workout intensity without straps, finger or electrodies. PulseTracer uses light-based technology to deliver heart data that it claims is as accurate as today's clumsy chest-straps. 

This blurry picture above is the first working prototype (the final design will be a lot sleeker), as worn by PulseTracer CEO Nadeem Kassam. The unit uses infrared illumination to follow your pulse, and also includes a 3D accelerometer and sensors for ambient and galvanic skin temperature.

"Taken together, the data gives extremely accurate caloric burns," says Kassam. "It can also be used for sleep and stress analysis - and it will totally do lie detection." Kassam says an API will allow developers to build apps for the watch - he promises that one of the first will be an iPhone app that taps the smartphone's GPS for the ultimate record of runs and bike rides.

The PulseTracer watch records heart data 24 hours a day for around a week between charges, and has Bluetooth and micro USB links for transferring data and recharging.

The PulseTracer goes on sale here in January for around $150 (plus a small monthly fee) - although Kassam is also interested in licensing the technology to hardware and software partners.