Russian twists are an essential core exercise that can be completed with or without weights. They focus on the sides of your core, also known as your obliques.

1. Sit on the ground with your knees bent and your feet flat, leaning back slightly.
2. Hold your hands together or a weight at your chest.
3. Rotate your torso to the right, bringing your hands or the weight beside your hip.
4. Rotate your torso to the left, bringing your hands or the weight beside your other hip.
5. Continue alternating sides.