Traditionally, abs are the coda at the end of a workout—those last five minutes you dedicate to crunches, situps, and planks.

Let’s rethink that.

“Your workout time is precious—and traditional abs exercises are an ineffective way of burning fat and building muscle given the limited number of muscles recruited and the low level of muscular overload,” says Brynn Putnam, founder of NYC’s high-intensity Refine Method.

Instead, Putnam recommends total-body movements that work mutiple muscles at once. “You’ll soon find that every exercise is a core exercise if you're working with enough resistance so your core muscles must stabilize your spine to allow your arms and legs to produce force,” she says. Suddenly, your 20-minute “abs” workout becomes a worthy sub for a full workout when time is tight.

Directions

Complete the following five exercises, one minute each, back-to-back and repeat for four rounds, resting only if you absolutely have to.

For more HIIT workouts

Check out the 10-minute total-body HIIT workout to burn fat, 10 HIIT workouts you can do at home, and the HIIT workout plan that motivates you to keep going.