Work It Out

THE CLASS:
Studio Cycling at Equinox, 131 Dartmouth St., Boston, 617-578-8918, equinox.com.

WHY DO IT?:
Short, intense speed intervals burn fat fast; the discomfort of the rock-hard seat will make you forget your burned-out quads.

WHAT IT’S LIKE:
After a warmup, participants are led through varying intervals of sprints and climbs of increasing intensity. Riders control the resistance, so it is possible to take it easy. But with a seriously motivating instructor (“You’re a machine that can do anything!”), it’ll be hard not to challenge yourself.

THE CLASS:
Bodyweight Blast at Sports Club/LA, 4 Avery St., Boston, 617-375-8200, thesportsclubla.com.

WHY DO IT?:
You use your own body weight for resistance – no wimping out with dinky dumbbells.

WHAT IT’S LIKE:
It’s blessedly gimmick-free, utilizing only a few hand weights and one ball. Designed to target key muscle groups, the class starts with slow curls, presses, and squats that get the arms and legs burning. Ball work then builds core strength and zeroes in on tough-to-target glutes. The final round of pushups and plank holds will leave you tender for days. But oh, it hurts so good!

THE CLASS:
Zumba at Healthworks Fitness, 300 Boylston St., Chestnut Hill, 617-383-6100, healthworksfitness.com.

WHY DO IT?:
Thirty to 60 minutes of hip-shimmying makes the class feel more dance club than health club – and because you’re having fun, the time flies.

WHAT IT’S LIKE:
A series of foot-stomping, hip-shaking mini routines timed to Latin, pop, and world-music rhythms, this is a seriously aerobic workout. Participants lunge, slide, and feverishly beat air drums. Keeping up with the fast-paced sequences can be tough for first-timers, but keep moving. It’ll get your heart pumping, and you’ll burn through cake-tasting calories in no time.