Depends what you want to do. Run a fast 5k? Improve aerobic system? Something else? Short fast bursts of running will improve your anearobic capacity. Slightly longer intervals run a bit slower may target your lactate threshold and lactate clearance rates. Slower running for longer distances will target your aerobic system.
As people, and the featured article, notes, short intense intervals may burn the most calories but I would argue for more well rounded fitness you need to do a bit of everything.
Due to HIIT, there's loads of people around the world now who have great anearobic metabolism but non-existant aerobic metabolism. The effects are increased autonomic stress from all the anearobic work and an inability to exercise for long durations without quite a lot of stress on your body.
As people, and the featured article, notes, short intense intervals may burn the most calories but I would argue for more well rounded fitness you need to do a bit of everything.
Due to HIIT, there's loads of people around the world now who have great anearobic metabolism but non-existant aerobic metabolism. The effects are increased autonomic stress from all the anearobic work and an inability to exercise for long durations without quite a lot of stress on your body.