In this video, Ozzie Jacobs shows how to activate your upper back muscles in order to tone them effectively when at the gym. As Ozzie explains, this is often more difficult to achieve due to the tendency of your shoulders to slump forward due to the effect of gravity. In order to properly activate your upper back muscles at a machine like a rowing machine, Ozzie advises her viewers to make sure that their back muscles are tightened, focusing and consciously trying to pull your shoulder blades together. By squeezing your shoulder blades together, you should activate your muscles. Then, continue this by challenging yourself by squeezing your shoulder blades tighter and holding the position for 2 seconds before releasing. By following these easy steps, you should be able to tone your upper back muscles with ease.