Casio’s first G-Shock was a tough little ticker, but it couldn’t do much apart from tell the time. Well, 40 years later, the looks haven’t changed much but what’s inside certainly has. The new DW-H5600 has an optical heart-rate monitor that can also detect your cardio load status and measure blood oxygen, plus a step counter, and sleep-tracking for recovery, with in-depth fitness tracking and analysis powered by Polar. Solar power will help keep the battery topped up for up to a month, or it’ll last nearly a year if you put it in power-saving mode. That turns off most of the features, though, so you won’t be able to do much more than tell the time. It’ll be like 1983 all over again.