Arguably the best things about summer start with the letter 's': sunshine, shorts, swimming, smoothies, surfing, and showing some skin. Sweat is on the list, too, but only if it's outdoors. To stop you from slaving in the gym for that fabled “summer bod” (whatever that means), here are ITG's four favorite apps and websites with quick, high intensity circuit training (HICT) workouts. They’ll save you time—and money—to spend on the more important summer 's' words.

The 7-minute Workout

You know what you can do in seven minutes? Make a perfectly soft boiled egg. Or, do a seven-minute HICT workout with comparable results a prolonged moderate intensity workout provides. The New York Times explains the science behind it. There’s even the 7-min.com app with timer and illustrations. Using only body weight, a chair, and the wall, hell, you could make the soft-boiled egg while working out at home. Then eat it while it’s still hot.

The Daily Hiit

Although the Daily Hiit is probably best for the fitness enthusiast with room for equipment—i.e. anyone who doesn’t live in New York—their 12-minute or less workouts will get you in serious shape. Also, their trainers provide great inspiration. (Did anyone else know it was possible to have that many visible muscles?)

The Do-Anywhere Workout

Brought to you by Equinox...for those who can’t afford it. But seriously, their 16-minute Do-Anywhere workout will kick your ass.

Nike Training Club

The N+TC app has over 100 workouts designed by master trainers with workout times spanning 15, 30, and 45 minutes. So you’re bound to find the best workout to fit your schedule and mood.

—Alexis Cheung