Similar to the principles of etiquette when you’re flying solo in the gym, it’s important ultimately to be respectful and considerate of both your group classmates and of your instructor. Especially when they are teaching oblique exercises. The group class environment is not personal training. You are receiving the benefit of trained instruction; however, the workout is not designed specifically to your individual needs. There is always a tension in that arrangement, however the benefit is that group fitness is much more cost-effective for you.
In addition to the basic rules of respect and consideration, make sure you are always on time to class. Do not enter a class late and disrupt the class. Not only is it not safe, since you have not participated in the warm-up, it can also distract other participant’s at a critical moment that could lead to an injury. Remember, it’s important to pay attention to form and technique when training.