FAILING TO ADD weight to ab exercises and training your core with only one movement are two of the worst mistakes you can make on your quest for a six-pack. The abs do much more than just crunch your torso, and they need to be worked against resistance to activate all their muscle fibers. Below is a plan for training your abs three different ways, and much harder than you’re used to.

Directions:

Perform a different one of the exercises at right after each regular workout for three sessions per week. For the weighted decline Russian twist and the decline situp, begin with 20 total reps, taking as many sets as you need to complete them. Rest 30 seconds between sets. Each time you repeat a workout, try to add five total reps. Continue up to 50 reps. For the plank, hold the position for 60 seconds total, and work up to 250 seconds.

Why it works:

Most guys train abs with flexion (crunches). This workout targets the abs’ other functions as well, such as rotating the torso and stabilizing it. Adding weight builds muscle size to make your abs stand out.

1. Weighted Decline Russian Twist

Set a bench to a 30-degree decline and secure your feet. Hold a weight plate (or medicine ball) at arm’s length. Now brace your core and twist to one side so your shoulders are turned 90 degrees. Twist the other way. That’s one rep.