You have the option to play your lectures at different speeds (.5x, 1x, 1.25x, 1.5x or 2x).
To change the speed of a particular lecture video, go to that lecture, and drag your mouse over the video. You will see a button in the bottom-left corner of the video giving you the option to change the speed.
Using Keyboard Shortcuts to Change the Video Speed
You can also change the video speed by using the keyboard shortcuts shift left and shift right. By clicking shift right, you can increase the video speed, and by clicking shift left you can decrease it.
You can also use the left arrow directional key to jump back 5 seconds in the video lecture, and the right arrow directional key to move forward 5 seconds.