The best virtual workouts designed to put you on the fast track to a better body.

FOR THE SUPER-BUSY
Equinox's Q Blog, with cardio and circuit-training videos from top trainers.

TIME COMMITMENT: 20 minutes per workout.
COST: Free at q.equinox.com.
THE SKINNY: Log on via your laptop, smartphone, or tablet to access over 25 hard- core workouts, most of which require nothing more than your body weight (squats, mountain climbers, and power jumps). Not to be skipped: the epic strength-circuit workout from trainer Josh Stolz, whose muscle-burning lunges, planks, and squats will tone up a flabby, cubicle-bound body.

FOR WEEKEND WARRIORS
Nike+ Kinect Training, a personalized coaching program for Xbox 360.

TIME COMMITMENT: 30 to 40 minutes per workout.
COST: $50 at nike.com.
THE SKINNY: Through the magic of motion- tracking technology, your trainer "sees" where your imbalances, strengths, and weaknesses are, then tailors instructions ("squat lower") accordingly. No slacking off permitted—your performance is assessed, recorded, and (if you choose) ranked against other online devotees.

FOR OVERACHIEVERS
Barre3, an online full-body workout to lengthen, strengthen, and tone.

TIME COMMITMENT: Ranges from 10-minute express classes to hour-long workouts.
COST: $15 a month at barre3.com.
THE SKINNY: This ballet-barre-inspired workout that incorporates yoga and Pilates and was created by Sadie Lincoln (Madonna's trainer) will kick your butt with calorie-torching exercises like painfully slow crunches and near impossible-squats done on the balls of your feet. Each routine requires nothing more than Wi-Fi and everyday gear like a chair and yoga mat.

FOR MENTOR-SEEKERS
The Prime Method, customizable yoga and Pilates workouts.

TIME COMMITMENT
: Less than an hour.

COST: $40 a month for all-access and live- streamed classes at theprimemethod.com.
THE SKINNY: A bona fide fitness coach (via iChat or Skype) maps out a 28-day training program and nutrition plan, along with goals specific to your needs (weight loss, body sculpting) and schedule. Access online workouts or "attend" live-streamed classes.
FOR TWITTER FIENDS
Fitocracy, a social-networking app that makes a game of working out.

TIME COMMITMENT: As little or as much as you want. You score points for tasks completed.
COST: Free for iPhone, iPad, and Android.
THE SKINNY: Select your fitness level and workout preferences, then earn points based on activities completed. Join workout groups or search for any exercise—crunches, for example—and get user-generated guidance, tips, and videos. Amass points, cultivate followers, and advance to the next level.

What Do You Think?