Spacewalks can be notoriously taxing on the body - a multi-hour spacewalk is often compared to a marathon in how much the astronaut must exert to overcome the stiffness of the suit.
I remember reading that in a couple of instances, astronauts have even lost fingernails over the course of a spacewalk. I have been unable to find any reference to this on the internet, however.
Is this true? Have astronauts lost fingernails during particularly gruelling spacewalks?