Wearables have become remarkably good at telling us what has already happened. They know how far we ran, how high our heart rate climbed, how well we slept afterwards and, increasingly, how much strain that workout placed on our bodies.
Could a smartwatch eventually recognise that you are heading towards an injury before you feel the first warning signs, or notice that your body is fighting an illness before you wake up feeling terrible? And, if it can, how much should you trust what it tells you to do?
