Are you a fan of 'jeffing'?I am that stereotypical runner – everyone in my life is sick of hearing about how strength training has transformed my workouts and my reasons for getting back into the sport in the first place. Bad news for them. I have another running obsession. “Jeffing,” named after Olympian and author Jeff Galloway, is a kind of lower-key fartlek (another 10/10 name). If both of those terms sound like gobbledegook, they refer to a period of slower walking (or running) before bursts of higher-energy sprints or jogging.Jeffing, also known as the