No, Jeffing is not a typo, but the technique of mixing running and walking in a single workout. And while it may sound counterintuitive, this run-walk method has been found to help runners become better at their sport – and at walking, too. You would initially repeat this cycle of run-walk, run-walk for a period of around 20 minutes, then, over time, lengthen the running intervals while shortening the walking ones. Jeffing is an affectionate term that recognizes US Olympian and author Jeff Galloway, who is a firm advocate of the run-walk coaching technique. But Jeffing isn't just for new runners – seasoned runners can also benefit from carefully constructed run-walk intervals and even use Jeffing to achieve new PRs.