The horses ran for a few more feet then stood, sides heaving.
The sides of their animals heaving, they stood silent and still.
Its sides heaved, and it was no longer running as a blur.
He sat on the brick floor of the tunnel, his sides heaving.
Her sides were heaving with fear and exertion, but she let herself be touched.
He flopped to the bottom of the boat, his sides heaving.
The black horse pulled at the bit, sides heaving like bellows.
The stallion's sides heaved from the speed of his journey.
The female now lay motionless, only her muddy sides heaving.
For a few moments he lay panting, his side heaving in exhaustion.