You can’t get a six-pack quickly, but you can work your way toward it with fairly short workouts—if you put in the effort. That’s where high-intensity interval training can come into play. By alternating intense isometric work (in the form of planks), targeted bending and twisting actions, and high-energy core cardio (mountain climbers), you’ll tax the core muscles in every way.

“Each move complements each other to target your entire core, which will help sculpt your six-pack,” says Derek DeGrazio, trainer and managing partner of Barry’s Bootcamp South Florida, who designed this workout.

Even though you’re going for time with these body-weight moves, you still want to focus heavily on your form, making every rep count. Enjoy those rest periods—your abs will be screaming for ‘em as the workout goes on.

60 seconds forearm plank

30 seconds mountain climbers

30 seconds rest

60 seconds right side plank

30 seconds mountain climbers

30 seconds rest

60 seconds left side plank

30 seconds mountain climbers

30 seconds rest

60 seconds leg raises

30 seconds mountain climbers

30 seconds rest

60 seconds reverse crunches

30 seconds mountain climbers

30 seconds rest

60 seconds jack knife

30 seconds mountain climbers

30 seconds rest

60 seconds bicycle crunches

30 seconds mountain climbers

30 seconds rest

60 seconds forearm plank

The 25 Most Effective Workout Finishers for Your Abs>>>