Fast sprints, fartlek [Swedish], in jogging was a thing 20+ years ago (Wikipedia says it was developed in 1930s). I got a knee injury and haven't jogged since,

Fast sprints, fartlek [Swedish], in jogging was a thing 20+ years ago (Wikipedia says it was developed in 1930s). I got a knee injury and haven't jogged since, is it still a thing? Is this HIT a refinement of that?