Are sit-ups good or bad for you? For a while ... Unlike hanging leg raises, the gentle twist helps engage even more core muscle, but if you know your hips tend to steal the spotlight, keep your knees ...

To work the lateral muscles while doing sit-ups, twist slightly to the left for five sit-ups, and then do the same thing to the right for five repetitions.

Optimal sets and reps: 3 to 4 sets of 15 to 30 reps As you come up in the traditional sit-up, twist your torso toward one side, bringing the opposite elbow toward the knee on the twisting side.