Running Full Tilt by Michael Currinder

Like most siblings, Leo and Caleb have a complicated relationship. But Caleb's violent outbursts literally send Leo running. When the family is forced to relocate due to Caleb's uncontrollable behavior, Leo tries to settle into a new school, joining the cross-country team and discovering his talent for racing and endurance for distance. Things even begin to look up for Leo when he befriends Curtis, a potential state champion who teaches Leo strategy and introduces him to would-be girlfriend, Mary. But Leo's stability is short-lived as Caleb escalates his attacks on his brother, resentful of his sport successes and new friendships.

Leo can't keep running away from his problems. But, with a little help from Curtis and Mary, he can appreciate his worth as a brother and his own capacity for growth, both on and off the field. (Goodreads.com)

Lexile: 810L