Stage 1 Abs Workouts
Start your first workout with the minimum number of sets and reps (for planks, start with the minimal amount of time). During the first several weeks try to progress slowly, performing more reps each time. When you can perform 20 reps, add a second set. For planks, when you can hold a plank for 45 seconds add a second set.
When you are able to perform 20 reps for 2 sets, add a third. When you can hold 2 sets of planks for 45 seconds (or more) each, add a third set. Move on to Stage 2 workouts when you are able to perform maximal reps for all sets in a given workout.
For standing cable crunches, pick a weight that is challenging and makes it difficult to perform 20 reps.