During different types of performances, the heart rate varies significantly. For example, studies have been done that show that heart rate varies throughout the different stages of a speech, which include leading up to a speaking role (the highest heart rate occurs during this stage), during the speaking role, and after the speaking role. Similar changes in heart rate also occur during acting, relating to stress. The high heart rates can be attributed to the stress caused by anticipation. During a performance with an audience, the actor experiences high levels of stress throughout the performance, as it pushes the actors mentally. However, this stress helps the actor have a stronger performance. Similar changes in heart rate occur for musicians during their performance. Though their heart rate is highest while they are musically performing, their heart rate is higher during the pre-performance phase, than during the post-performance phase, which is attributed to the stress caused by anticipation. The anticipation leading up to a performance, causes heart rate to increase, while the relief after a performance, causes the heart rate to decrease.