eelslake

As a teenager, I spent summers working for my Dad, who was a carpenter/house builder.
All the crew loved framing, of course. As one master woodworker once said to me "Everyone loves framing".
It was a game to frame the house as quickly as possible, and a game to pound the most nails. I swung my claw hammer as hard and as fast as possible.
The problem came at night while sleeping. My upper arm would ache incredibly; I would be in agony.
The next day, I'd be back at it, swinging that hammer as hard and fast as I could. And the next night, my arm would ache again.
Sounds like a titanium hammer would have been the answer. Not only could I have pounded more nails, but maybe my arm would not have kept me awake.