Around the time of his work towards the great mural of the Battle of Anghiari, Leonardo made many studies of male nudes, both in action and, as here, at rest. These were not directly preparatory for the Battle, but background research, a survey of the body in the manner of a series of architectural elevations. The model spreads his legs to equalise his weight distribution - while it was important for expressive purposes to know how to draw the muscles in tension, it was just as important to know how to draw them when relaxed. Though the shading of the body is very subtle, almost every superficially visible muscle is clearly depicted. Artistic beauty and anatomical accuracy are in perfect balance