What exercise flattens your stomach best?

The best exercise for flattening your stomach is a combination of aerobic exercise and strength training. Aerobic exercise, such as running, swimming, or cycling, helps to burn calories and reduce body fat. Strength training, such as crunches, planks, and other core exercises, helps to strengthen and tone the abdominal muscles. A combination of both types of exercise is the most effective way to flatten your stomach.