Americans Erin Jackson and Jordan Stolz won speed skating World Cup races in the absence of their top Dutch rivals on Friday.

And when it’s better to hold back. You’ve completed a few half marathons, and your sights are set on a new goal: breaking two hours. You download a training plan designed to help you do just that.

Typically, distance runners should aim to start this work in an ‘off season’ period of foundation training to allow the space ...