Core exercises that effectively target the core include planks, crunches, and Russian twists. Planks engage multiple core muscles simultaneously, improving stability and posture. Crunches specifically strengthen the rectus abdominis, the muscle responsible for the "six-pack" appearance. Meanwhile, Russian twists enhance lateral core strength and improve rotational movement, critical for various physical activities. A balanced routine incorporating these exercises contributes to a strong and stable core, benefiting overall fitness.