The smart apparel developer has now raised more than $51m altogether, securing funding from backers including apparel producer Mas Holdings.

US-based fitness apparel producer Athos closed a $35.5m series C round led by Social Capital yesterday that also included Sri Lanka-based apparel manufacturer Mas Holdings.

Venture capital firms Lightspeed Venture Partners, Felix Capital, DCM and True Ventures, as well as Joe Lacob, managing partner and chairman of basketball team the Golden State Warriors.

Founded in 2012, Athos produces smart training apparel that measures muscle performance, heart rate and acceleration. The data is then sent to a user’s mobile device, allowing…