The secret to melting fat? This brand of high-intensity interval training

This Japanese import is super effective-and super hard! Yes, it's short (20 seconds on, 10 seconds off for as little as 4 minutes), but you have to go all out to get the big benefits. Sammie Kennedy, a Toronto-based personal trainer and creator of Booty Camp Fitness Ultimate Home Edition 2, shows off a Tabata-style routine in the video above. Follow along, and you'll be looking as fit as she does in no time flat.