8 Bluetooth 4.0 Fitness Gadgets

There's no need to own both a real bicycle and an at-home spin bike. When the weather keeps you indoors, pop the back wheel off of your 10-speed or BMX and mount your bike onto the Wahoo Fitness KICKR Power Trainer bike stand. KICKR connects to the Wahoo iPhone app and monitors your power (wattage), speed, and cadence. Or use the app to control the KICKR's resistance for a more challenging ride. The trainer adjusts to accommodate most bikes and foldable legs make it easy to store or tote. ($1,099, wahoofitness.com)