high intensity interval training

“I am in the best physical shape I have ever been in," said one fan of high-intensity interval training.
HIIT (high-intensity interval training) has been the most buzzed-about sweat method for a while, but there's a new approach gaining momentum: LISS, or low-intensity, steady-state cardio. OK, it's not really new (hello, elliptical!). So why the sudden spotlight?
Grab a partner and scroll down for Training Mate's 30-minute HIIT workout--we guarantee it'll be way more entertaining than your usual jog-and-gossip sesh.
"It's a little bit of step, a little bit of weights. It's great music. It's fun. It's hard but it's fun."