How heavy was plate armor?

One of many dubious stories I heard in history class was that knights had to be winched onto horses because their armor was so heavy, and if they fell on the ground, they were completely helpless.

This modern re-enactment shows an obstacle course competition between a soldier, a firefighter, and a knight in plate armor. The outcome: looks like a tie!

Knights and soldiers in my novel (Journey of Souls) do not wear plate armor because it had not been invented yet. A 13th-century soldier typically wore a gambeson (a quilted jacket) with a mail shirt or tunic over it, and sometimes an additional tunic over that.