Thousands of people around the world have tried this and succeeded in their wish.

The most effective exercise is the plank. Usually people think it is too simple so they avoid it and skip it during their exercise.

It helps to melt more fat than sit-ups and it helps to strengthen the internal and external muscles of the back and the core. It also helps to strengthen the muscles of the buttocks, arms and legs.

This is the perfect exercise for push-up positions letting the muscles work properly. The push-ups should not be lengthened or shortened but deeply strong and durable.

This exercise should be finished in four weeks, increased with time.

Start by holding the plank position for 20 seconds. At the final weeks the goal will be to continue to sit in this position for four minutes with no pause. The body can endure this challenge and the muscles can do it as well.

The important thing is to do the plank correct. The body should remain in the straight line while you lift yourself on your elbows and lean on your toes.

Take a deep breath and control your abdominal muscles remaining in `this position, while the neck and head will be the extension of the back. The weight should be on the elbows and the feet so that the glutes are strained and enhanced with it restore balance to the body.

You need to learn the correct position so that you can take the 28 day challenge. Here are the times of how long you should remain in this position every day.

Day 1 : 20 seconds

Day 2: 20 seconds

Day 3: 30 seconds

Day 4: 30 seconds

Day 5: 40 seconds

Day 6: rest

Day 7: 45 seconds

Day 8: 45 seconds

Day 9: 60 seconds

Day 10: 60 seconds

Day 11: 60 seconds

Day 12: 90 seconds

Day 13: rest

Day 14: 90 seconds

Day 15: 90 seconds

Day 16: 120 seconds

Day 17: 120 seconds

Day 18: 150 seconds

Day 19: rest

Day 20: 150 seconds

Day 21 150 seconds

Day 22: 180 seconds

Day 23: 180 seconds

Day 24: 210 seconds

Day 25: rest

Day 26: 210 seconds

Day 27: 240 seconds

Day 28: the longest you can

You need to feel reaction the first twenty seconds. You can change some parts if you like but you need to maintain the principle. You can increase the reps of sit-ups or crunches.