Crunches, sit-ups, squats, and deadlifts are some of the most frequent core ab workouts. Bodyweight crunches and sit-ups are the most frequent core ab workouts. Lying on your back with your knees bent at a 45-degree angle, complete a sit-up. Standing up after a sit-up is important too! Lie on your stomach to do a crunch. Bodyweight squats, lunges, and bridges are great abs exercises as well. Start with 10 repetitions of each exercise and work your way up over time. Deadlifts are another great ab exercise that works all parts of the abdominal wall. The deadlift allows you to lift more weight than other common ab exercises because you are using muscle power instead of just your muscles. It is recommended that you use a spotter for this exercise. Crunches and sit-ups can be used daily to strengthen your core. Try not to skip any days when doing ab exercises so that you do not develop a weak core. A strong core helps protect you from injury and also improves your posture.