While G-shock timepieces are known for their robustness, Casio's designers took things a step further with the Move GBDH1000, which boasts optical sensors in addition to Bluetooth and GPS tracking. The GDH1000 is the most sophisticated fitness and activity tracker in the G-shock lineup thanks to its combination of modern features and a timeless design. Together with other helpful sensors like a temperature, barometer, and accelerometer, the GBDH1000 now has an optical heart rate sensor, enhancing its usefulness as a training and exercise planning tool.