7-Day Abs Workout Routine: Get a Strong Core at Home Day 1: 3 sets of 15-20 crunches 3 sets of 15-20 leg raises 3 sets of 15-20 Russian twists Day 2: 3 sets of 15-20 planks (hold each plank for 30 seconds) 3 sets of 15-20 side planks (hold each side plank for 30…