Side Plank : When you can hold this plank position for a minute easily, you can increase the challenge on your obliques by either holding a weight on top of your hips.
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Lying Windshield Wipers : To make this exercise harder, you can increase the speed of the movement without slamming your feet into the floor so that you need to break harder in the eccentric phase.
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Ab Wheel Roll-Out : The ab wheel roll-out is one of the best exercises you can do for the front of your core, mainly your rectus abdominus but also the front-most muscle fibers of your obliques.
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Crunches : Don’t skimp on the classics. If this exercise is too easy for you, you can increase the resistance by holding a small weight against your chest, perform crunches on a ball or declined bench, or try cable crunches.
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Back Extension : Make sure to begin light in this exercise as you get accustomed to it, and then gradually make it harder by holding a weight against your chest, or by extending your arms over your head, away from your hips.
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Oblique Sit-Up : I recommend you alternate between your left and right sides in every rep of this exercise. To make the exercise harder, try holding a weight against your chest or perform the oblique sit-ups on a ball or declined bench.
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Hanging Leg Raise : The final exercise for the front of your core in this list is the hanging leg raise. This exercise will work your hip flexors dynamically while your abs have to work hard.
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