He was breathing quickly, as if he'd been running.

"I thought you might be cold," he said, breathing quickly.

He was breathing quickly now, the blood pounding in his ears.

She breathed quickly, as if she'd just run a long way.

She was staring at him, her eyes wide, breathing quickly.

She was breathing quickly now, all too aware of what lay in store for her.

Both she and Nick were breathing quickly from the demands of the dance.

Do not breathe quickly, or you may start to hyperventilate.

Her cheeks were hot with annoyance and she was breathing quickly.