Here’s a 30-day ab challenge designed specifically for women to help strengthen and tone your core muscles and promote a flat tummy. This beginner-friendly workout gradually increases in intensity over the course of 30 days:

Day 1-5:

1. Basic Crunches: 3 sets of 10 reps
2. Plank: Hold for 20-30 seconds
3. Leg Raises: 3 sets of 8 reps
4. Russian Twists: 2 sets of 10 reps (each side)
5. Bicycle Crunches: 2 sets of 10 reps (each side)

Day 6-10:

1. Reverse Crunches: 3 sets of 10 reps
2. Mountain Climbers: 2 sets of 15 reps (each leg)
3. Side Plank (each side): Hold for 20-30 seconds
4. Flutter Kicks: 3 sets of 12 reps (each leg)
5. Plank with Hip Dips: 2 sets of 10 reps (each side)

Day 11-15:

1. Vertical Leg Crunches: 3 sets of 10 reps
2. Toe Touches: 2 sets of 12 reps
3. Bird Dogs: 2 sets of 10 reps (each side)
4. Side Plank with Leg Lift (each side): Hold for 20-30 seconds
5. Oblique Crunches: 2 sets of 10 reps (each side)

Day 16-20:

1. V-Ups: 3 sets of 8 reps
2. Plank with Shoulder Taps: 2 sets of 10 reps (each side)
3. Mountain Climbers with Twist: 2 sets of 12 reps (each leg)
4. Side Plank Reach-Through (each side): 2 sets of 8 reps
5. Scissor Kicks: 3 sets of 12 reps

Day 21-25:

1. Jackknife Crunches: 3 sets of 8 reps
2. Plank with Knee to Elbow: 2 sets of 10 reps (each side)
3. Pulse Ups: 3 sets of 10 reps
4. Side Plank Hip Lifts (each side): 2 sets of 10 reps
5. Russian Twists with Dumbbell: 2 sets of 12 reps (each side)

Day 26-30:

1. Hollow Body Hold: Hold for 20-30 seconds
2. Spiderman Plank: 2 sets of 10 reps (each side)
3. Standing Oblique Crunches (each side): 3 sets of 12 reps
4. Plank Jacks: 2 sets of 15 reps
5. Bicycle Crunches with Twist: 3 sets of 12 reps (each side)

Remember to maintain proper form throughout each exercise and listen to your body. Additionally, pair this ab challenge with a balanced diet and regular cardio exercise for optimal results in achieving a flat tummy and overall weight loss. Always consult with a healthcare professional before starting any new exercise program.