Activity tracking
Activity tracking
Not necessarily directly aimed at serious athletes, the Apple Watch has a range of activity tracking features built in.
These range from those that analyse heart rate data collected by the aforementioned optical monitor, to a step counter and even calories burned (although that one, as ever, will have to be taken as a very rough estimate).
How useful these are in training terms remains to be seen, but off the top of our heads we reckon they’d be a decent way to measure whether your rest days really are restful!