The Russian Twist is an abdominal exercise that primarily works the obliques, which are the muscles located on the sides of your abdomen. It also works the rectus abdominis (abs), transverse abdominis (deep core muscles), and the hip flexors.

The Russian Twist is an exercise that can be performed as often as you'd like, but it's important to remember to take a break if you start to feel any strain or discomfort. It's also important to make sure you are using proper form and technique when performing the exercise. Generally, it's recommended to perform the Russian Twist 2-3 times per week, with 1-2 sets of 10-15 reps per session.

Safety considerations for the Russian Twist include: 1. Make sure to maintain good posture throughout the exercise. Keep your back straight and your core engaged. 2. Make sure to keep your feet flat on the ground and your knees bent at a 90 degree angle. 3. Do not twist your torso too far as this can cause strain on your lower back. 4. Make sure to use a weight that is appropriate for your fitness level. 5. Make sure to keep your breathing steady and controlled throughout the exercise.

Common mistakes to avoid with the Russian Twist include: 1. Not engaging the core: Make sure to keep your core engaged throughout the entire exercise to get the most out of it. 2. Not going slow enough: Make sure to go slow and controlled with the Russian Twist to ensure you are engaging the correct muscles. 3. Not using proper form: Make sure to keep your back straight and your feet off the ground during the exercise. 4. Not focusing on the obliques: Make sure to focus on engaging your obliques throughout the exercise.