I notice a big difference when I get impatient and rush my warm up sets. Sometimes I am not able to lift as heavy as normal when I go to the heavy weights too fast. Sometimes I feel like my technique is compromised or that the right muscles arent activating. Other times Ill start to feel niggles that let me know I rushed the heavy weights.Proper warm up sets are especially with your shoulders. This is such a complex muscle group, its so important to properly warm up to your heavy lifts.