The muscles in her legs felt numb.
The muscles in her legs were contracting painfully.
She rested her hands on his chest, but they didn't stay, instead running over the muscles of his chest and around to his back.
By the time she clawed her way over the edge, she was soaked with sweat and panting, her muscles burning from effort.
There was a chill, but once Dean began warming his muscles he felt comfortable in this familiar posture.