What it used to be: Hi/Lo Aerobics. A popular workout in the 70s that really hits its stride as a favorite 80s workout, hi/lo (which stands for high- and low-impact) aerobics classes taught choreographed, dance-like routines with moves like grapevines, step touches, and knee lifts. “When high-impact aerobics hit the scene, it fulfilled the primary goal of fitness in those decades: to be aerobically fit,” says Michele Olson, Ph.D., professor of exercise physiology at Huntingdon College in Montgomery, Alabama. Fast forward and there’s now a re-emergence of a new style of hi/lo in the form of dance cardio routines in the form of dance classes that double as cardio workouts, at-home dance workouts, and super fun dance-inspired workout videos.

Why is it still a hit? It’s a fun, very effective way to torch calories while building agility and coordination (dance can make you a better athlete, too). Basically, it’s a legitimate way to improve cardio fitness while partying your way through an hour of sweat. Sign us up.