How do you know when wrist-worn technology is officially a trend? When a brand best known for its printers gets in on the action. As promised, Epson is launching its first wrist-based wearables, and they're all about improving your fitness. Each line delivers a slight twist on a familiar formula. The Runsense GPS watch range (shown above) can track your running even if it loses signal thanks to stride sensors on some models, and lasts for a healthy 30 hours of continuous tracking; you may not need to recharge for days. The Pulsense line, meanwhile, monitors your heart rate, activity and sleep quality using a blend of optical and motion sensors. You theoretically never have to take the tracker off, although the 36-hour battery suggests you'll be doing that quite often.